US3558910A - Relay circuits employing a triac to prevent arcing - Google Patents

Relay circuits employing a triac to prevent arcing Download PDF

Info

Publication number
US3558910A
US3558910A US746149A US3558910DA US3558910A US 3558910 A US3558910 A US 3558910A US 746149 A US746149 A US 746149A US 3558910D A US3558910D A US 3558910DA US 3558910 A US3558910 A US 3558910A
Authority
US
United States
Prior art keywords
triac
relay
input terminal
relay contact
semiconductor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US746149A
Inventor
Robert G Dale
Gary V Fay
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Motorola Solutions Inc
Original Assignee
Motorola Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Motorola Inc filed Critical Motorola Inc
Application granted granted Critical
Publication of US3558910A publication Critical patent/US3558910A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
    • H01H9/54—Circuit arrangements not adapted to a particular application of the switching device and for which no provision exists elsewhere
    • H01H9/541—Contacts shunted by semiconductor devices
    • H01H9/542—Contacts shunted by static switch means
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/51—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used
    • H03K17/56—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices
    • H03K17/72—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices having more than two PN junctions; having more than three electrodes; having more than one electrode connected to the same conductivity region
    • H03K17/725—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices having more than two PN junctions; having more than three electrodes; having more than one electrode connected to the same conductivity region for ac voltages or currents

Definitions

  • a bilateral semiconductor switch such as a semiconductor triac connected in parallel with the contacts of an electromechanical relay.
  • the relay and triac are connected in series with the AC source and the load.
  • Circuit means are connected between a gate electrode of the triac and circuit input terminals to which the AC source is connected and provides turn-on gate current for the triac prior to and during the closure of the electromechanical relay contacts to prevent effects of contact bounce.
  • This circuit means also provides a sustaining or hold current to the triac subsequent to the opening of the relay contacts and thereby prevents contact arcing.
  • the triac conducts before the relay contacts close and after the relay contacts 10 n i 14 2a I l I a l l l l l l l RELAY cincurrs EMPLOYING A TRIAC TO PREVENT ARCING I BACKGROUND OF TI'IEINVENTION .
  • -Prior art power control circuits have employed electromechanical relays of the type having a coil operative to close relay contacts when energized by alternatingcurrent. When the relay contacts open and close, there is a substantial amount of arcing due to the high electrical field between the contacts, and this arcing causes early contact failure'because of the burning produced by the arcing. Because of the arcing, the sizeand expense of the relay contacts are much. greater than would be required in the absence of such arcing. The areing also generates noise and causes transients to be transmitted on the AC line. In addition, the contact bounce that takes place when the contacts close causes the contacts to wear and produces undesirable effects on the load.
  • a further object of this invention is to provide a circuit of DESCRIPTION or THE DRAWINGS IFIG. 1 is a schematic diagram vention.
  • FIG. 2 is a schematic diagram of an alternative embodiment ofthe invention. Corresponding components in FIGS. 1 and 2 share the same reference numerals.
  • the circuit embodying the present invention tincludes a bilateral semiconductor switch such as a triac connected in parallel with electromechanical relay contacts between an AC source and a load.
  • a first circuit means is connected between circuit input terminals and a control electrode of the semiconductor switch for turning on the switch prior to the time that the relay contacts close, thereby preventing arcing and the effects of contact bounce upon contact closure.
  • a second circuit means is connected to the first circuitmeans and provides a sustaining or holding current to the semiconductor switch after the relay contacts open to prevent arcing between the contacts upon the opening thereof.
  • FIG. 1 a power line;;11 which interconnects a load 14 and a pairof input terminals 10 and 12.
  • a mechanical switch 16 is connected between the input terminal 10 and electromechanical relay means 20 and is used to initiate switching action for connectin'g fan AC source 13 to the load 14.
  • the electromechanical relay means 20 including a relay coil 22 and relay contacts 24 and25 is electromechanically coupled to the AC line 11 as shown and the coil 22 isconnected to receive an energizing potential from the AC source 13 upon closure of electromechanical switch l th
  • a diode 18 is connected between th e switch 16 and a common junction 31 between first and second resistors 30 and 32.
  • the diode l8 ensures that capacitor 34 charges in a positive direction as shown in the drawings.
  • the first resistor 30 constitutes a first circuit means connected-to, a control or gate electrode 28 of the semiconductor switch 26 and provides turn-on gate current forthe semiconductor switch 26.
  • the resistor 32 and capacitor 34 constitute a second circuit means and provide sustaining or holding current to the semiconduc!
  • the bilateral semiconductor switch 26 is preferably a solid state device identified as a triac, and this triac can be triggered into conduction in either direction by positive or negative polarity signals on gate electrode 28.
  • the triac structure is well known in the semiconductor art and the Motorola Type No. MAC2-4 may be used as switch 26 in FIGS. 1 and 2.
  • the triacs semiconductor structure includes.
  • the gate. region of the triac comprises P- and N-type subregions which are electrically connected to the gate electrode2 8- and respond to the nega-. tive an and positive polarity gate signals, respectively. 7
  • the resistor30 has two functions in the circuit depending on whether the switch 16 has just been opened or whether the switch 16 has just been closed. If the switch 16 has just been closed, resistor 30 provides a path for gate current to flow into the gate electrode 28 as previously explained. If the switch 16 has just been opened, the resistor 30 provides a current path for the discharge of capacitor 34 to maintain semiconductor switch 26 conducting after the contacts 24 and 25 are opened by the electromechanical action of the relay means 20. At this time the capacitor 34 discharges through resistors 30 and 32 into the gate electrode of semiconductor switch 26 and into the load 14.
  • the electrical network consisting of resistor 36 and capacitor 38 controls the rate of change of voltage across the switch 26. This network insures that the switch 26 will not be triggered by rapid changes in voltage caused by closing or opening of contacts 24 and 25 or by voltage transients or'surges on the power line 11.
  • the semiconductor switch 26 which draws turn: on gate current immediately upon the closure of switch
  • the semiconductor switch 26 immediately shorts out the relay contacts 24 and 25 and eliminates the high electric field otherwise present at these contacts.
  • the contacts 24 and 25 close without contact arcing or effects of the contact bounce and there is .no chopping of the line voltage.
  • the initial load current is supplied through the semiconductor switch 26 until such time. as the relay contacts 24 and 25 close. At this time, current flows through the relay contacts 24 and 25 to the load 14 even though there is'a potential on the gate electrode 28 of the semiconductor switch 26.
  • the capacitor 34 charges in a positive direction (as shown).
  • the capacitor 34 discharges through resistors 30 and 32 to maintain the semiconductor switch 26 conducting during the opening of contacts 24 and 25, thus preventing arcing.
  • the semiconductor switch 26 conducts prior to the. closure of the contacts 24 and 25 and remains conducting after the contacts 24 and 25 are opened by the respective energization and deenergization of the relay coil 22.
  • the capacitor 34 discharges into the gate 28 of the switch 26 and maintains switch 26 conducting for at least a few cycles after the contacts 24 and 25 open.
  • FIG. 2 illustrates an alternative embodiment of the invention wherein a half wave rectifier 18a is connected between the relay coil 22 and the mechanical switch 16.
  • the relay coil 22 is energized by a rectified half wave voltage which is also applied to the first and second circuit means at node3l in the above-described resistance-capacitance network.
  • the circuit shown in FIG. 2 operates in the manner identical to that described above with reference to FIG. 1. Since there is no diode blocking between the capacitor 34 and the relay coil 22 in FIG. 2, the capacitor 34 will discharge through coil 22 at the same time it is discharging into the gate electrode 28 to maintain the triac 26 conducting.
  • the second resistor 32 can be selected sufficiently large in value to limit the current flowing in relay coil 22 to a value insufficient to operate relay contacts 24 and 25. This requirement is not difficult to meet since gate current for the triac 26 is normally less than the value of current required to actuate the contacts 24 and 25.
  • the bilateral semiconductor switch 16 could be replaced with any device (solid state or otherwise) which is responsive to a pulse of gate current to perform the relay contact shunting function described above.
  • One such device may for example include two semiconductor controlled rectifiers (SCRs) connected in parallel with their gate electrodes connected together.
  • SCRs semiconductor controlled rectifiers
  • Circuitry for controlling the flow of current from an AC source to a load including, in combination:
  • a.'relay contact means connected between a load terminal and input terminal means; r e i b. electroresponsive means coupled between said input terminal means and said relaycontact means for closing said relaycontact means a given time after an input voltage is applied to said electroresponsive means:
  • a multilayer semiconductor switch connected in parallel with said relay contact means, said multilayer semiconductor switch having a gateregion connected to a control electrode and responsive to negative and positive polarity signals to shunt said relay contact means;
  • first circuit means including-a diode and a-first resistor serially connected between said control electrode of said nected to said'first resistor, said capacitor discharging into said control electrode of said semiconductor switch to maintain said semiconductor switch conducting subsequent to the opening of said relay contact means.
  • circuitry defined in claim 2 which further includes resistance-capacitance network means connected in shunt with said semiconductor switch and responsive to rapid changes in AC line voltage to prevent triggering of said semiconductor switch.
  • said resistance capacitance network means consists of a resistor and capaci; tor connected in series across said semiconductor switch and across said relay contact means.
  • Circuitry for controlling the flow of current from an AC source to a load including, in combination:
  • a. relay contact means connected between a first input tet
  • electroresponsive means coupled between the first input terminal and said relay contact means for closing said relay contact means a given time after an input voltage is applied to said electroresponsive means
  • charge storage means connected between said second rethrough said firstand second resistors into the gate eIectrode of said semiconductor triac to sustain conduction wsistor anda second input terminal, said means receiving a' therein and prevent arcing in said relay contact means after an energizing voltage is removed from said electroresponsive means.
  • said electroresponsive means includes an electromechanical relay including an inductor serially connected through a switch across a pair of input terminals for receiving an AC energizing voltage when said switch is v closed.

Landscapes

  • Relay Circuits (AREA)

Abstract

Disclosed is circuitry for controlling the flow of current from an AC source to a load and includes a bilateral semiconductor switch such as a semiconductor triac connected in parallel with the contacts of an electromechanical relay. The relay and triac are connected in series with the AC source and the load. Circuit means are connected between a gate electrode of the triac and circuit input terminals to which the AC source is connected and provides turn-on gate current for the triac prior to and during the closure of the electromechanical relay contacts to prevent effects of contact bounce. This circuit means also provides a sustaining or hold current to the triac subsequent to the opening of the relay contacts and thereby prevents contact arcing. The triac conducts before the relay contacts close and after the relay contacts open.

Description

- United States Patent Inventors Appl. No.
RELAY CIRCUITS EMPLOYING A TRIAC TO PREVENT ARCING 13 Claims, 2 Drawing Figs.
Robert G. Dale 3,389,301 6/1968 Siwko 307/136 Tempe; 3,402,302 9/1968 Coburn 307/133 Gary V. Fay, Scottsdale, Ariz. 3,328,606 6/1967 Pinckaers.... 32l/45DT 746,149. 3,348,131 10/1967 Banks 32l/45DT July 19, 1968 3,474,293 10/ 1969 Siwko et a]. 307/136X 1971 Primary Examiner-Robert K. Schaefer Motorola, Inc.
Assistant Examiner-T. B. .Iorke Franklin Park, Ill.
. Attorney Mueller and Archele a corporation of Illinois ABSTRACT: Disclosed is circuitry for controlling the flow of Int. Cl
Field of Search UNITED STATES PATENTS 3,184,619 5/1965 Zydney 3,339,110 8/1967 Jones,Jr
307/136, 317/11 ..H0lh 33/59 307/134, 133, 136; 317/1 1.4; 302/252, 305A References Cited 307/134X open.
current from an AC source to a load and includes a bilateral semiconductor switch such as a semiconductor triac connected in parallel with the contacts of an electromechanical relay. The relay and triac are connected in series with the AC source and the load. Circuit means are connected between a gate electrode of the triac and circuit input terminals to which the AC source is connected and provides turn-on gate current for the triac prior to and during the closure of the electromechanical relay contacts to prevent effects of contact bounce. This circuit means also provides a sustaining or hold current to the triac subsequent to the opening of the relay contacts and thereby prevents contact arcing. The triac conducts before the relay contacts close and after the relay contacts 10 n i 14 2a I l I a l l l l l l RELAY cincurrs EMPLOYING A TRIAC TO PREVENT ARCING I BACKGROUND OF TI'IEINVENTION .-Prior art power control circuits have employed electromechanical relays of the type having a coil operative to close relay contacts when energized by alternatingcurrent. When the relay contacts open and close, there is a substantial amount of arcing due to the high electrical field between the contacts, and this arcing causes early contact failure'because of the burning produced by the arcing. Because of the arcing, the sizeand expense of the relay contacts are much. greater than would be required in the absence of such arcing. The areing also generates noise and causes transients to be transmitted on the AC line. In addition, the contact bounce that takes place when the contacts close causes the contacts to wear and produces undesirable effects on the load.
SUMMARY OF THE INVENTION electromechanical relay contacts used therein have been greatly reduced for a given current rating. 1- v I -A further object of the present invention is to provide a power control circuit having a long lifetime and in which the effects of contact bounce have been'eliminated.
A further object of this invention is to provide a circuit of DESCRIPTION or THE DRAWINGS IFIG. 1 is a schematic diagram vention; and
FIG. 2 is a schematic diagram of an alternative embodiment ofthe invention. Corresponding components in FIGS. 1 and 2 share the same reference numerals.
BRIEF DESCRIPTION OF THE INVENTION ...Briefly described, the circuit embodying the present inventiontincludes a bilateral semiconductor switch such as a triac connected in parallel with electromechanical relay contacts between an AC source and a load. A first circuit means is connected between circuit input terminals and a control electrode of the semiconductor switch for turning on the switch prior to the time that the relay contacts close, thereby preventing arcing and the effects of contact bounce upon contact closure. A second circuit means is connected to the first circuitmeans and provides a sustaining or holding current to the semiconductor switch after the relay contacts open to prevent arcing between the contacts upon the opening thereof.
' jDETAlLED DESCRIPTION or THE INVENTION .Referring to the drawing, there is shown in FIG. 1 a power line;;11 which interconnects a load 14 and a pairof input terminals 10 and 12. A mechanical switch 16 is connected between the input terminal 10 and electromechanical relay means 20 and is used to initiate switching action for connectin'g fan AC source 13 to the load 14. I
of one embodiment of the in- The electromechanical relay means 20 including a relay coil 22 and relay contacts 24 and25 is electromechanically coupled to the AC line 11 as shown and the coil 22 isconnected to receive an energizing potential from the AC source 13 upon closure of electromechanical switch l th A diode 18 is connected between th e switch 16 and a common junction 31 between first and second resistors 30 and 32. The diode l8 ensures that capacitor 34 charges in a positive direction as shown in the drawings. The first resistor 30 constitutes a first circuit means connected-to, a control or gate electrode 28 of the semiconductor switch 26 and provides turn-on gate current forthe semiconductor switch 26. The resistor 32 and capacitor 34 constitute a second circuit means and provide sustaining or holding current to the semiconduc! tor switch 26 to maintain switch 26 conducting after the relay contacts 24 and 25 have been opened by the deenergization of relay coil 22. The diode 18 provides a path for turn-on gate current through resistor 30 to the gate electrode 28 of the AC semiconductor switch 26. The bilateral semiconductor switch 26 is preferably a solid state device identified as a triac, and this triac can be triggered into conduction in either direction by positive or negative polarity signals on gate electrode 28. The triac structure is well known in the semiconductor art and the Motorola Type No. MAC2-4 may be used as switch 26 in FIGS. 1 and 2. The triacs semiconductor structure includes. parallel PNPN conductiye paths which are alternately driven into conduction upon positive and negative polarity signals respectively applied to the gate or control electrode 28 of the bilateral semiconductor switch 26'. The gate. region of the triac comprises P- and N-type subregions which are electrically connected to the gate electrode2 8- and respond to the nega-. tive an and positive polarity gate signals, respectively. 7
The resistor30 has two functions in the circuit depending on whether the switch 16 has just been opened or whether the switch 16 has just been closed. If the switch 16 has just been closed, resistor 30 provides a path for gate current to flow into the gate electrode 28 as previously explained. If the switch 16 has just been opened, the resistor 30 provides a current path for the discharge of capacitor 34 to maintain semiconductor switch 26 conducting after the contacts 24 and 25 are opened by the electromechanical action of the relay means 20. At this time the capacitor 34 discharges through resistors 30 and 32 into the gate electrode of semiconductor switch 26 and into the load 14.
The electrical network consisting of resistor 36 and capacitor 38 controls the rate of change of voltage across the switch 26. This network insures that the switch 26 will not be triggered by rapid changes in voltage caused by closing or opening of contacts 24 and 25 or by voltage transients or'surges on the power line 11.
DESCRIPTION OF OPERATION When mechanical switch 16 in FIG. 1 is closed to energize relay coil 22, there is a time delay between the initial energiz'ation of relay coil 22 and the closure of contacts 24v and 25. Similarly, there is a time delay between the deenergization of relaycoil 22 and the opening of relay contacts 24 and 25 by well-known electromechanical relay action.
When the relay coil 22 is energized and in the absence of the semiconductor switch 26 and the associated circuitry according to the present invention, there is a bouncing of contacts 24 and 25 and an arcing therebetween caused by the high electric field between the open contacts 24 and 25. This bouncing chops the voltage waveform on power line 11, and the arcing and bouncing limits the contact lifetime. v v
In accordance with the present invention, the above problems associated with contact arcing and bounce are eliminated by the semiconductor switch 26 which draws turn: on gate current immediately upon the closure of switch The semiconductor switch 26 immediately shorts out the relay contacts 24 and 25 and eliminates the high electric field otherwise present at these contacts. Thus, the contacts 24 and 25 close without contact arcing or effects of the contact bounce and there is .no chopping of the line voltage. The initial load current is supplied through the semiconductor switch 26 until such time. as the relay contacts 24 and 25 close. At this time, current flows through the relay contacts 24 and 25 to the load 14 even though there is'a potential on the gate electrode 28 of the semiconductor switch 26. After switch 16 is closed, the capacitor 34 charges in a positive direction (as shown).
When the relay coil 22 is deenergized, the capacitor 34 discharges through resistors 30 and 32 to maintain the semiconductor switch 26 conducting during the opening of contacts 24 and 25, thus preventing arcing. Thus, the semiconductor switch 26 conducts prior to the. closure of the contacts 24 and 25 and remains conducting after the contacts 24 and 25 are opened by the respective energization and deenergization of the relay coil 22. The capacitor 34 discharges into the gate 28 of the switch 26 and maintains switch 26 conducting for at least a few cycles after the contacts 24 and 25 open.
FIG. 2 illustrates an alternative embodiment of the invention wherein a half wave rectifier 18a is connected between the relay coil 22 and the mechanical switch 16. In this embodi ment of the invention, the relay coil 22 is energized by a rectified half wave voltage which is also applied to the first and second circuit means at node3l in the above-described resistance-capacitance network. In all other regards, the circuit shown in FIG. 2 operates in the manner identical to that described above with reference to FIG. 1. Since there is no diode blocking between the capacitor 34 and the relay coil 22 in FIG. 2, the capacitor 34 will discharge through coil 22 at the same time it is discharging into the gate electrode 28 to maintain the triac 26 conducting. However, the second resistor 32 can be selected sufficiently large in value to limit the current flowing in relay coil 22 to a value insufficient to operate relay contacts 24 and 25. This requirement is not difficult to meet since gate current for the triac 26 is normally less than the value of current required to actuate the contacts 24 and 25.
The following is a table of resistance and capacitance values used in a circuit of a type described which has been built and successfully operated.
TABLE Component Value Resistor:
30 kilohms 1.
36 -do 47 Capacitor:
34 microfarads 38 do 0. 1 Triac 26 (type) Motorola MAC2-4 The present invention may be practiced other than as specifically described above. For example, within the scope of the present invention, the bilateral semiconductor switch 16 could be replaced with any device (solid state or otherwise) which is responsive to a pulse of gate current to perform the relay contact shunting function described above. Onesuch device may for example include two semiconductor controlled rectifiers (SCRs) connected in parallel with their gate electrodes connected together. The switch 26 may be fabricated in monolithic, hybrid or discrete component form within the scope of this invention. Accordingly,=-said inventionis limited only by way of the following appended claims.
We, claim: a 1. Circuitry for controlling the flow of current from an AC source to a load including, in combination:
a.'relay contact means connected between a load terminal and input terminal means; r e i b. electroresponsive means coupled between said input terminal means and said relaycontact means for closing said relaycontact means a given time after an input voltage is applied to said electroresponsive means:
c. a multilayer semiconductor switch connected in parallel with said relay contact means, said multilayer semiconductor switch having a gateregion connected to a control electrode and responsive to negative and positive polarity signals to shunt said relay contact means;
d. first circuit meansincluding-a diode and a-first resistor serially connected between said control electrode of said nected to said'first resistor, said capacitor discharging into said control electrode of said semiconductor switch to maintain said semiconductor switch conducting subsequent to the opening of said relay contact means.
3. The circuitry defined in claim 2 wherein said diode is connected between a common junction between said first and second resistors and said input terminal means.
4. The circuitry defined in claim 2 wherein said diode is connected in series with said relay means across said input ter minal means, said relay means including a relay coil which is electromechanically coupled to said relay contact means for closing said relay contact means. i 5. The circuitry defined in claim 2 wherein said relay mean includes a relay coil which is connected across said input terminal means, said circuitry further including a diode connected between said input terminal means and said common junction between said first and second resistors.
6. The circuitry defined in claim 5 wherein said diode is connected directly between said common junction and said input terminal means. i
7. The circuitry defined in claim 2 which further includes resistance-capacitance network means connected in shunt with said semiconductor switch and responsive to rapid changes in AC line voltage to prevent triggering of said semiconductor switch.
8. The circuitry defined in claim 7 wherein said resistance capacitance network means consists of a resistor and capaci; tor connected in series across said semiconductor switch and across said relay contact means.
9. Circuitry for controlling the flow of current from an AC source to a load including, in combination:
a. relay contact means connected between a first input tet;
minal and a load terminal;
b. electroresponsive means coupled between the first input terminal and said relay contact means for closing said relay contact means a given time after an input voltage is applied to said electroresponsive means;
c. a semiconductor triac connected in parallelwith said relay contact means and having a gate electrode for receiving gate current for turning on said semiconductor tr1ac;" 1 v t d. afirst resistor connected to the gate electrode of said semiconductor triac; I
- aera second resistor connected to 'said first resistor;
x f. charge storage means connected between said second rethrough said firstand second resistors into the gate eIectrode of said semiconductor triac to sustain conduction wsistor anda second input terminal, said means receiving a' therein and prevent arcing in said relay contact means after an energizing voltage is removed from said electroresponsive means.
10. Circuitry defined in claim 9 wherein said semiconductor triac includes parallel. PNPN conductive paths which are alternately rendered conductive upon the application of positive and negative polarity signals to said gate electrode of said a. said' diode is connected in parallel with said electroresponsive means; and
said electroresponsive means includes an electromechanical relay including an inductor serially connected through a switch across a pair of input terminals for receiving an AC energizing voltage when said switch is v closed.
13. The circuitry defined in claim I] wherein said diode is connected between said input terminal and one end of an inductor in said electroresponsive means so that said electroresponsive means; said semiconductor triac, and said capacitor are all energized by a rectified energizing voltage.

Claims (13)

1. Circuitry for controlling the flow of current from an AC source to a load including, in combination: a. relay contact means connected between a load terminal and input terminal means; b. electroresponsive means coupled between said input terminal means and said relay contact means for closing said relay contact means a given time after an input voltage is applied to said electroresponsive means: c. a multilayer semiconductor switch connected in parallel with said relay contact means, said multilayer semiconductor switch having a gate region connected to a control electrode and responsive to negative and positive polarity signals to shunt said relay contact means; d. first circuit means including a diode and a first resistor serially connected between said control electrode of said semiconductor switch and said input terminal means, said first circuit means applying a turn-on current to said semiconductor switch prior to the time said relay contact means close; and e. second circuit means connected to said first circuit means and providing a current to said control electrode of said multilayer semiconductor switch to maintain conduction in said multilayer semiconductor switch after said relay contact means opens.
2. The circuitry defined in claim 1 wherein said second circuit means includes a second resistor and a capacitor connected to said first resistor, said capacitor discharging into said control electrode of said semiconductor switch to maintain said semiconductor switch conducting subsequent to the opening of said relay contact means.
3. The circuitry defined in claim 2 wherein said diode is connected between a common junction between said first and second resistors and said input terminal means.
4. The circuitry defined in claim 2 wherein said diode is connected in series with said relay means across said input terminal means, said relay means including a relay coil which is electromechanically coupled to said relay contact means for closing said relay contact means.
5. The circuitry defined in claim 2 wherein said relay means includes a relay coil which is connected across said input terminal means, said circuitry further including a diode connected between said input terminal means and said common junction between said first and second resistors.
6. The circuitry defined in claim 5 wherein said diode is connected directly between said common junction and said input terminal means.
7. The circuitry defined in claim 2 which further includes resistance-capacitance network means connected in shunt with said semiconductor switch and responsive to rapid changes in AC line voltage to prevent triggering of said semiconductor switch.
8. The circuitry defined in claim 7 wherein said resistance-capacitance network means consists of a resistor and capacitor connected in series across said semiconductor switch and across said relay contact means.
9. Circuitry for controlling the flow of current from an AC source to a load including, in combination: a. relay contact means connected between a first input terminal and a load terminal; b. electroresponsive means coupled between the first input terminal and said relay contact means for closing said relay contact means a given time after an input voltage is applied to said electroresponsive means; c. a semiconductor triac connected in parallel with said relay contact means and having a gate electrode for receiving gate current for turning on said semiconductor triac; d. a first resistor connected to the gate electrode of said semiconductor triac; e. a second resistor connected to said firsT resistor; f. charge storage means connected between said second resistor and a second input terminal, said means receiving a charge sufficient to sustain conduction in said semiconductor triac after an energizing voltage is removed from said electroresponsive means; and g. interconnecting circuit means connected between said first input terminal and a point intermediate said first and second resistors so that said first resistor limits the turn-on gate current to said semiconductor triac when the latter is turned on and said storage means discharges through said first and second resistors into the gate electrode of said semiconductor triac to sustain conduction therein and prevent arcing in said relay contact means after an energizing voltage is removed from said electroresponsive means.
10. Circuitry defined in claim 9 wherein said semiconductor triac includes parallel PNPN conductive paths which are alternately rendered conductive upon the application of positive and negative polarity signals to said gate electrode of said triac.
11. The circuitry defined in claim 9 wherein said interconnecting circuit means includes a diode connected between said input terminal and said point intermediate said first and second resistors, so that said semiconductor triac and said capacitor are energized by a rectified voltage of one polarity.
12. The circuitry defined in claim ll wherein: a. said diode is connected in parallel with said electroresponsive means; and b. said electroresponsive means includes an electromechanical relay including an inductor serially connected through a switch across a pair of input terminals for receiving an AC energizing voltage when said switch is closed.
13. The circuitry defined in claim ll wherein said diode is connected between said input terminal and one end of an inductor in said electroresponsive means so that said electroresponsive means, said semiconductor triac, and said capacitor are all energized by a rectified energizing voltage.
US746149A 1968-07-19 1968-07-19 Relay circuits employing a triac to prevent arcing Expired - Lifetime US3558910A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US74614968A 1968-07-19 1968-07-19

Publications (1)

Publication Number Publication Date
US3558910A true US3558910A (en) 1971-01-26

Family

ID=24999662

Family Applications (1)

Application Number Title Priority Date Filing Date
US746149A Expired - Lifetime US3558910A (en) 1968-07-19 1968-07-19 Relay circuits employing a triac to prevent arcing

Country Status (1)

Country Link
US (1) US3558910A (en)

Cited By (63)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3786337A (en) * 1972-02-17 1974-01-15 Reinhausen Maschf Scheubeck Thyristors for effecting tap changing on transformers and including current limiting resistors and standby trigger system
US3982137A (en) * 1975-03-27 1976-09-21 Power Management Corporation Arc suppressor circuit
US4025820A (en) * 1976-03-11 1977-05-24 Power Management Corporation Contactor device including arc supression means
US4074333A (en) * 1976-07-15 1978-02-14 Shinko Electric Company, Ltd. A.c. relay system
US4152634A (en) * 1976-12-22 1979-05-01 Power Management Corporation Power contactor and control circuit
US4225895A (en) * 1977-11-28 1980-09-30 Hjertman Bengt N V Device for closing or interrupting an electric alternating current arising on a line
US4296449A (en) * 1979-08-27 1981-10-20 General Electric Company Relay switching apparatus
US4360740A (en) * 1981-09-01 1982-11-23 Conard Albert F Low voltage switching circuit for controlling a high voltage electrical load
FR2538608A1 (en) * 1982-12-28 1984-06-29 Lgt Lab Gen Telecomm Electronic device for protecting the contactor circuit of a relay and relay equipped with such a device.
US4525762A (en) * 1983-10-07 1985-06-25 Norris Claude R Arc suppression device and method
DE3432025A1 (en) * 1984-08-31 1986-03-13 Kromberg & Schubert, 5600 Wuppertal Switching apparatus, especially for switching high-power current loads on and off
US4598330A (en) * 1984-10-31 1986-07-01 International Business Machines Corporation High power direct current switching circuit
US4700256A (en) * 1984-05-16 1987-10-13 General Electric Company Solid state current limiting circuit interrupter
US4704652A (en) * 1986-01-27 1987-11-03 Westinghouse Electric Corp. Hybrid electrical power controller
DE3718634A1 (en) * 1986-06-02 1987-12-03 In Suk Kim ARC-FREE ELECTROMAGNETIC SWITCH
DE3701838A1 (en) * 1987-01-23 1988-08-04 Hella Kg Hueck & Co DEVICE FOR PROTECTING RELAY CONTACTS
US4772809A (en) * 1983-11-28 1988-09-20 Omron Tateisi Electronics Co. Switching circuit and a relay device employed to prevent arcing
US4939776A (en) * 1988-09-20 1990-07-03 Siemens Transmission Systems, Inc. Logic signal circuit for a releasing relay
USRE33314E (en) * 1984-10-10 1990-08-28 Mars Incorporated Vending machine power switching apparatus
US4991050A (en) * 1989-09-18 1991-02-05 Allen-Bradley Company, Inc. Method and device for protecting starters from fault currents
US5072203A (en) * 1989-09-18 1991-12-10 Allen-Bradley Company, Inc. Method and device for protecting starters from fault currents
US5633540A (en) * 1996-06-25 1997-05-27 Lutron Electronics Co., Inc. Surge-resistant relay switching circuit
US5637964A (en) * 1995-03-21 1997-06-10 Lutron Electronics Co., Inc. Remote control system for individual control of spaced lighting fixtures
US5987205A (en) * 1996-09-13 1999-11-16 Lutron Electronics Co., Inc. Infrared energy transmissive member and radiation receiver
CN1046591C (en) * 1993-09-24 1999-11-17 富士电机株式会社 Driving circuit of electromagnetic switch
US6037721A (en) * 1996-01-11 2000-03-14 Lutron Electronics, Co., Inc. System for individual and remote control of spaced lighting fixtures
US6621668B1 (en) 2000-06-26 2003-09-16 Zytron Control Products, Inc. Relay circuit means for controlling the application of AC power to a load using a relay with arc suppression circuitry
US6624989B2 (en) * 2001-05-18 2003-09-23 Franklin Electric Company, Inc. Arc suppressing circuit employing a triggerable electronic switch to protect switch contacts
US20040179313A1 (en) * 2000-08-09 2004-09-16 Cleveland Andrew J. Active arc-supression circuit, system, and method of use
US20050094328A1 (en) * 2003-10-14 2005-05-05 John Weiss Electrical power connector
US20050123408A1 (en) * 2003-12-08 2005-06-09 Koehl Robert M. Pump control system and method
US20050226731A1 (en) * 2004-04-09 2005-10-13 A.O. Smith Corporation Controller for a motor and a method of controlling the motor
US20060127227A1 (en) * 2004-04-09 2006-06-15 A.O. Smith Corporation Controller for a motor and a method of controlling the motor
US20070014055A1 (en) * 2005-07-14 2007-01-18 Ness Keith D Apparatus and method for relay contact arc suppression
US20070163929A1 (en) * 2004-08-26 2007-07-19 Pentair Water Pool And Spa, Inc. Filter loading
US20080095638A1 (en) * 2006-10-13 2008-04-24 A.O. Smith Corporation Controller for a motor and a method of controlling the motor
US20080095640A1 (en) * 2006-10-13 2008-04-24 A.O. Smith Corporation Controller for a motor and a method of controlling the motor
US20080266742A1 (en) * 2007-04-30 2008-10-30 Watlow Electric Manufacturing Company Apparatus and method for increasing switching life of electromechanical contacts in a hybrid power switching device
US20100080714A1 (en) * 2008-10-01 2010-04-01 A. O. Smith Corporation Controller for a motor and a method of controlling the motor
US20100134931A1 (en) * 2008-12-01 2010-06-03 Sergio Orozco Hybrid power relay with thermal protection
US20100254825A1 (en) * 2004-08-26 2010-10-07 Stiles Jr Robert W Pumping System with Power Optimization
US20100310382A1 (en) * 2009-06-09 2010-12-09 Melissa Drechsel Kidd Method of Controlling a Pump and Motor
US20110002792A1 (en) * 2004-04-09 2011-01-06 Bartos Ronald P Controller for a motor and a method of controlling the motor
US20110052416A1 (en) * 2004-08-26 2011-03-03 Robert Stiles Variable Speed Pumping System and Method
US20110076156A1 (en) * 2004-08-26 2011-03-31 Stiles Jr Robert W Flow Control
US20110091329A1 (en) * 2004-08-26 2011-04-21 Stiles Jr Robert W Pumping System with Two Way Communication
US20110187286A1 (en) * 2010-02-01 2011-08-04 Lutron Electronics Co., Inc. Switching Circuit Having Delay For Inrush Current Protection
US20110187332A1 (en) * 2010-02-01 2011-08-04 Lutron Electronics Co., Inc. Switching Circuit Having Delay For Inrush Current Protection
US20110222191A1 (en) * 2010-03-12 2011-09-15 Reinhold Henke Two Terminal Arc Suppressor
US8281425B2 (en) 2004-11-01 2012-10-09 Cohen Joseph D Load sensor safety vacuum release system
US8313306B2 (en) 2008-10-06 2012-11-20 Pentair Water Pool And Spa, Inc. Method of operating a safety vacuum release system
US8436559B2 (en) 2009-06-09 2013-05-07 Sta-Rite Industries, Llc System and method for motor drive control pad and drive terminals
US8469675B2 (en) 2004-08-26 2013-06-25 Pentair Water Pool And Spa, Inc. Priming protection
US8564233B2 (en) 2009-06-09 2013-10-22 Sta-Rite Industries, Llc Safety system and method for pump and motor
US8602745B2 (en) 2004-08-26 2013-12-10 Pentair Water Pool And Spa, Inc. Anti-entrapment and anti-dead head function
US20150035485A1 (en) * 2013-08-02 2015-02-05 Delta Electronics, Inc. Electric vehicle supply equipment and method of operating the same
US9243413B2 (en) 2010-12-08 2016-01-26 Pentair Water Pool And Spa, Inc. Discharge vacuum relief valve for safety vacuum release system
US9307622B2 (en) 2014-08-22 2016-04-05 Lutron Electronics Co., Inc. Three-way switching circuit having delay for inrush current protection
US9404500B2 (en) 2004-08-26 2016-08-02 Pentair Water Pool And Spa, Inc. Control algorithm of variable speed pumping system
US9531215B2 (en) 2004-07-31 2016-12-27 Server Technology, Inc. Transfer switch with arc suppression
US9885360B2 (en) 2012-10-25 2018-02-06 Pentair Flow Technologies, Llc Battery backup sump pump systems and methods
WO2018046708A1 (en) * 2016-09-09 2018-03-15 Eaton Industries (Austria) Gmbh Circuit breaker
US10465676B2 (en) 2011-11-01 2019-11-05 Pentair Water Pool And Spa, Inc. Flow locking system and method

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3184619A (en) * 1962-08-30 1965-05-18 Bell Telephone Labor Inc Contact noise suppressor
US3328606A (en) * 1964-11-02 1967-06-27 Honeywell Inc Scr bidirectional switch apparatus having variable impedance input control circuit
US3339110A (en) * 1964-05-13 1967-08-29 Navigational Comp Corp Relay circuits
US3348131A (en) * 1964-08-11 1967-10-17 Encore Mfg Corp A-c power control circuit having a trigger means with a voltage breakdown device connected to the base of a unijunction transistor
US3389301A (en) * 1965-10-21 1968-06-18 Fenwal Inc Arc suppressing circuit
US3402302A (en) * 1962-09-28 1968-09-17 Dynamic Controls Corp Radio noise-free switch
US3474293A (en) * 1965-10-23 1969-10-21 Fenwal Inc Arc suppressing circuits

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3184619A (en) * 1962-08-30 1965-05-18 Bell Telephone Labor Inc Contact noise suppressor
US3402302A (en) * 1962-09-28 1968-09-17 Dynamic Controls Corp Radio noise-free switch
US3339110A (en) * 1964-05-13 1967-08-29 Navigational Comp Corp Relay circuits
US3348131A (en) * 1964-08-11 1967-10-17 Encore Mfg Corp A-c power control circuit having a trigger means with a voltage breakdown device connected to the base of a unijunction transistor
US3328606A (en) * 1964-11-02 1967-06-27 Honeywell Inc Scr bidirectional switch apparatus having variable impedance input control circuit
US3389301A (en) * 1965-10-21 1968-06-18 Fenwal Inc Arc suppressing circuit
US3474293A (en) * 1965-10-23 1969-10-21 Fenwal Inc Arc suppressing circuits

Cited By (139)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3786337A (en) * 1972-02-17 1974-01-15 Reinhausen Maschf Scheubeck Thyristors for effecting tap changing on transformers and including current limiting resistors and standby trigger system
US3982137A (en) * 1975-03-27 1976-09-21 Power Management Corporation Arc suppressor circuit
DE2612437A1 (en) * 1975-03-27 1976-10-14 Power Management Corp ARC SUPPRESSION CIRCUIT
US4025820A (en) * 1976-03-11 1977-05-24 Power Management Corporation Contactor device including arc supression means
US4074333A (en) * 1976-07-15 1978-02-14 Shinko Electric Company, Ltd. A.c. relay system
US4152634A (en) * 1976-12-22 1979-05-01 Power Management Corporation Power contactor and control circuit
US4225895A (en) * 1977-11-28 1980-09-30 Hjertman Bengt N V Device for closing or interrupting an electric alternating current arising on a line
US4296449A (en) * 1979-08-27 1981-10-20 General Electric Company Relay switching apparatus
US4360740A (en) * 1981-09-01 1982-11-23 Conard Albert F Low voltage switching circuit for controlling a high voltage electrical load
FR2538608A1 (en) * 1982-12-28 1984-06-29 Lgt Lab Gen Telecomm Electronic device for protecting the contactor circuit of a relay and relay equipped with such a device.
US4525762A (en) * 1983-10-07 1985-06-25 Norris Claude R Arc suppression device and method
US4772809A (en) * 1983-11-28 1988-09-20 Omron Tateisi Electronics Co. Switching circuit and a relay device employed to prevent arcing
US4855612A (en) * 1983-11-28 1989-08-08 Omron Tateisi Electronics Co. Switching current and a relay device employed therein
US4700256A (en) * 1984-05-16 1987-10-13 General Electric Company Solid state current limiting circuit interrupter
DE3432025A1 (en) * 1984-08-31 1986-03-13 Kromberg & Schubert, 5600 Wuppertal Switching apparatus, especially for switching high-power current loads on and off
USRE33314E (en) * 1984-10-10 1990-08-28 Mars Incorporated Vending machine power switching apparatus
US4598330A (en) * 1984-10-31 1986-07-01 International Business Machines Corporation High power direct current switching circuit
US4704652A (en) * 1986-01-27 1987-11-03 Westinghouse Electric Corp. Hybrid electrical power controller
DE3718634A1 (en) * 1986-06-02 1987-12-03 In Suk Kim ARC-FREE ELECTROMAGNETIC SWITCH
US4802051A (en) * 1986-06-02 1989-01-31 In Suk Kim Arc-free electromagnetic contactor
FR2600207A1 (en) * 1986-06-16 1987-12-18 Gen Electric Current-limiting circuit interrupter with solid body
DE3701838A1 (en) * 1987-01-23 1988-08-04 Hella Kg Hueck & Co DEVICE FOR PROTECTING RELAY CONTACTS
US4939776A (en) * 1988-09-20 1990-07-03 Siemens Transmission Systems, Inc. Logic signal circuit for a releasing relay
US4991050A (en) * 1989-09-18 1991-02-05 Allen-Bradley Company, Inc. Method and device for protecting starters from fault currents
US5072203A (en) * 1989-09-18 1991-12-10 Allen-Bradley Company, Inc. Method and device for protecting starters from fault currents
CN1046591C (en) * 1993-09-24 1999-11-17 富士电机株式会社 Driving circuit of electromagnetic switch
US5637964A (en) * 1995-03-21 1997-06-10 Lutron Electronics Co., Inc. Remote control system for individual control of spaced lighting fixtures
US6037721A (en) * 1996-01-11 2000-03-14 Lutron Electronics, Co., Inc. System for individual and remote control of spaced lighting fixtures
US6310440B1 (en) 1996-01-11 2001-10-30 Lutron Electronics Company, Inc. System for individual and remote control of spaced lighting fixtures
US5633540A (en) * 1996-06-25 1997-05-27 Lutron Electronics Co., Inc. Surge-resistant relay switching circuit
US5987205A (en) * 1996-09-13 1999-11-16 Lutron Electronics Co., Inc. Infrared energy transmissive member and radiation receiver
US6621668B1 (en) 2000-06-26 2003-09-16 Zytron Control Products, Inc. Relay circuit means for controlling the application of AC power to a load using a relay with arc suppression circuitry
US7259945B2 (en) * 2000-08-09 2007-08-21 Server Technology, Inc. Active arc-suppression circuit, system, and method of use
US20040179313A1 (en) * 2000-08-09 2004-09-16 Cleveland Andrew J. Active arc-supression circuit, system, and method of use
US6624989B2 (en) * 2001-05-18 2003-09-23 Franklin Electric Company, Inc. Arc suppressing circuit employing a triggerable electronic switch to protect switch contacts
US20050094328A1 (en) * 2003-10-14 2005-05-05 John Weiss Electrical power connector
US10289129B2 (en) 2003-12-08 2019-05-14 Pentair Water Pool And Spa, Inc. Pump controller system and method
US8540493B2 (en) 2003-12-08 2013-09-24 Sta-Rite Industries, Llc Pump control system and method
US10642287B2 (en) 2003-12-08 2020-05-05 Pentair Water Pool And Spa, Inc. Pump controller system and method
US10416690B2 (en) 2003-12-08 2019-09-17 Pentair Water Pool And Spa, Inc. Pump controller system and method
US8444394B2 (en) 2003-12-08 2013-05-21 Sta-Rite Industries, Llc Pump controller system and method
US10409299B2 (en) 2003-12-08 2019-09-10 Pentair Water Pool And Spa, Inc. Pump controller system and method
US20050123408A1 (en) * 2003-12-08 2005-06-09 Koehl Robert M. Pump control system and method
US20080131286A1 (en) * 2003-12-08 2008-06-05 Koehl Robert M Pump controller system and method
US10241524B2 (en) 2003-12-08 2019-03-26 Pentair Water Pool And Spa, Inc. Pump controller system and method
US20080260540A1 (en) * 2003-12-08 2008-10-23 Koehl Robert M Pump controller system and method
US9328727B2 (en) 2003-12-08 2016-05-03 Pentair Water Pool And Spa, Inc. Pump controller system and method
US9371829B2 (en) 2003-12-08 2016-06-21 Pentair Water Pool And Spa, Inc. Pump controller system and method
US9399992B2 (en) 2003-12-08 2016-07-26 Pentair Water Pool And Spa, Inc. Pump controller system and method
US20100068073A1 (en) * 2004-04-09 2010-03-18 A. O. Smith Corporation Controller for a motor and a method of controlling the motor
US8133034B2 (en) 2004-04-09 2012-03-13 Regal Beloit Epc Inc. Controller for a motor and a method of controlling the motor
US20060127227A1 (en) * 2004-04-09 2006-06-15 A.O. Smith Corporation Controller for a motor and a method of controlling the motor
US20050226731A1 (en) * 2004-04-09 2005-10-13 A.O. Smith Corporation Controller for a motor and a method of controlling the motor
US8353678B2 (en) 2004-04-09 2013-01-15 Regal Beloit Epc Inc. Controller for a motor and a method of controlling the motor
US8282361B2 (en) 2004-04-09 2012-10-09 Regal Beloit Epc Inc. Controller for a motor and a method of controlling the motor
US20110002792A1 (en) * 2004-04-09 2011-01-06 Bartos Ronald P Controller for a motor and a method of controlling the motor
US8177520B2 (en) 2004-04-09 2012-05-15 Regal Beloit Epc Inc. Controller for a motor and a method of controlling the motor
US9531215B2 (en) 2004-07-31 2016-12-27 Server Technology, Inc. Transfer switch with arc suppression
US9551344B2 (en) 2004-08-26 2017-01-24 Pentair Water Pool And Spa, Inc. Anti-entrapment and anti-dead head function
US10415569B2 (en) 2004-08-26 2019-09-17 Pentair Water Pool And Spa, Inc. Flow control
US11391281B2 (en) 2004-08-26 2022-07-19 Pentair Water Pool And Spa, Inc. Priming protection
US11073155B2 (en) 2004-08-26 2021-07-27 Pentair Water Pool And Spa, Inc. Pumping system with power optimization
US10947981B2 (en) 2004-08-26 2021-03-16 Pentair Water Pool And Spa, Inc. Variable speed pumping system and method
US10871163B2 (en) 2004-08-26 2020-12-22 Pentair Water Pool And Spa, Inc. Pumping system and method having an independent controller
US10871001B2 (en) 2004-08-26 2020-12-22 Pentair Water Pool And Spa, Inc. Filter loading
US20110076156A1 (en) * 2004-08-26 2011-03-31 Stiles Jr Robert W Flow Control
US10731655B2 (en) 2004-08-26 2020-08-04 Pentair Water Pool And Spa, Inc. Priming protection
US20110052416A1 (en) * 2004-08-26 2011-03-03 Robert Stiles Variable Speed Pumping System and Method
US10527042B2 (en) 2004-08-26 2020-01-07 Pentair Water Pool And Spa, Inc. Speed control
US10502203B2 (en) 2004-08-26 2019-12-10 Pentair Water Pool And Spa, Inc. Speed control
US10480516B2 (en) 2004-08-26 2019-11-19 Pentair Water Pool And Spa, Inc. Anti-entrapment and anti-deadhead function
US20110091329A1 (en) * 2004-08-26 2011-04-21 Stiles Jr Robert W Pumping System with Two Way Communication
US20070163929A1 (en) * 2004-08-26 2007-07-19 Pentair Water Pool And Spa, Inc. Filter loading
US10240604B2 (en) 2004-08-26 2019-03-26 Pentair Water Pool And Spa, Inc. Pumping system with housing and user interface
US20100254825A1 (en) * 2004-08-26 2010-10-07 Stiles Jr Robert W Pumping System with Power Optimization
US10240606B2 (en) 2004-08-26 2019-03-26 Pentair Water Pool And Spa, Inc. Pumping system with two way communication
US9932984B2 (en) 2004-08-26 2018-04-03 Pentair Water Pool And Spa, Inc. Pumping system with power optimization
US9777733B2 (en) 2004-08-26 2017-10-03 Pentair Water Pool And Spa, Inc. Flow control
US8465262B2 (en) 2004-08-26 2013-06-18 Pentair Water Pool And Spa, Inc. Speed control
US8469675B2 (en) 2004-08-26 2013-06-25 Pentair Water Pool And Spa, Inc. Priming protection
US8480373B2 (en) 2004-08-26 2013-07-09 Pentair Water Pool And Spa, Inc. Filter loading
US8500413B2 (en) 2004-08-26 2013-08-06 Pentair Water Pool And Spa, Inc. Pumping system with power optimization
US9605680B2 (en) 2004-08-26 2017-03-28 Pentair Water Pool And Spa, Inc. Control algorithm of variable speed pumping system
US9404500B2 (en) 2004-08-26 2016-08-02 Pentair Water Pool And Spa, Inc. Control algorithm of variable speed pumping system
US8573952B2 (en) 2004-08-26 2013-11-05 Pentair Water Pool And Spa, Inc. Priming protection
US8602745B2 (en) 2004-08-26 2013-12-10 Pentair Water Pool And Spa, Inc. Anti-entrapment and anti-dead head function
US9051930B2 (en) 2004-08-26 2015-06-09 Pentair Water Pool And Spa, Inc. Speed control
US8840376B2 (en) 2004-08-26 2014-09-23 Pentair Water Pool And Spa, Inc. Pumping system with power optimization
US8801389B2 (en) 2004-08-26 2014-08-12 Pentair Water Pool And Spa, Inc. Flow control
US8281425B2 (en) 2004-11-01 2012-10-09 Cohen Joseph D Load sensor safety vacuum release system
US20070014055A1 (en) * 2005-07-14 2007-01-18 Ness Keith D Apparatus and method for relay contact arc suppression
US7385791B2 (en) 2005-07-14 2008-06-10 Wetlow Electric Manufacturing Group Apparatus and method for relay contact arc suppression
US8177519B2 (en) 2006-10-13 2012-05-15 Regal Beloit Epc Inc. Controller for a motor and a method of controlling the motor
US20080095638A1 (en) * 2006-10-13 2008-04-24 A.O. Smith Corporation Controller for a motor and a method of controlling the motor
US20080095640A1 (en) * 2006-10-13 2008-04-24 A.O. Smith Corporation Controller for a motor and a method of controlling the motor
US7690897B2 (en) 2006-10-13 2010-04-06 A.O. Smith Corporation Controller for a motor and a method of controlling the motor
US8360736B2 (en) 2006-10-13 2013-01-29 Regal Beloit Epc Inc. Controller for a motor and a method of controlling the motor
US20090290990A1 (en) * 2006-10-13 2009-11-26 Brian Thomas Branecky Controller for a motor and a method of controlling the motor
US20100232981A1 (en) * 2006-10-13 2010-09-16 Brian Thomas Branecky Controller for a motor and a method of controlling the motor
WO2008134383A1 (en) * 2007-04-30 2008-11-06 Watlow Electric Manufacturing Company Apparatus and method for increasing switching life of electromechanical contacts in a hybrid power switching device
US20080266742A1 (en) * 2007-04-30 2008-10-30 Watlow Electric Manufacturing Company Apparatus and method for increasing switching life of electromechanical contacts in a hybrid power switching device
US8354809B2 (en) 2008-10-01 2013-01-15 Regal Beloit Epc Inc. Controller for a motor and a method of controlling the motor
US20100080714A1 (en) * 2008-10-01 2010-04-01 A. O. Smith Corporation Controller for a motor and a method of controlling the motor
US8602743B2 (en) 2008-10-06 2013-12-10 Pentair Water Pool And Spa, Inc. Method of operating a safety vacuum release system
US10724263B2 (en) 2008-10-06 2020-07-28 Pentair Water Pool And Spa, Inc. Safety vacuum release system
US9726184B2 (en) 2008-10-06 2017-08-08 Pentair Water Pool And Spa, Inc. Safety vacuum release system
US8313306B2 (en) 2008-10-06 2012-11-20 Pentair Water Pool And Spa, Inc. Method of operating a safety vacuum release system
US8089735B2 (en) * 2008-12-01 2012-01-03 Custom Sensors & Technologies, Inc. Hybrid power relay with thermal protection
US20100134931A1 (en) * 2008-12-01 2010-06-03 Sergio Orozco Hybrid power relay with thermal protection
US8564233B2 (en) 2009-06-09 2013-10-22 Sta-Rite Industries, Llc Safety system and method for pump and motor
US9712098B2 (en) 2009-06-09 2017-07-18 Pentair Flow Technologies, Llc Safety system and method for pump and motor
US8436559B2 (en) 2009-06-09 2013-05-07 Sta-Rite Industries, Llc System and method for motor drive control pad and drive terminals
US11493034B2 (en) 2009-06-09 2022-11-08 Pentair Flow Technologies, Llc Method of controlling a pump and motor
US9556874B2 (en) 2009-06-09 2017-01-31 Pentair Flow Technologies, Llc Method of controlling a pump and motor
US10590926B2 (en) 2009-06-09 2020-03-17 Pentair Flow Technologies, Llc Method of controlling a pump and motor
US20100310382A1 (en) * 2009-06-09 2010-12-09 Melissa Drechsel Kidd Method of Controlling a Pump and Motor
WO2011094665A3 (en) * 2010-02-01 2012-01-26 Lutron Electronics Company, Inc. Switching circuit having delay for inrush current protection
US8278839B2 (en) 2010-02-01 2012-10-02 Lutron Electronics Co., Inc. Switching circuit having delay for inrush current protection
US20110187286A1 (en) * 2010-02-01 2011-08-04 Lutron Electronics Co., Inc. Switching Circuit Having Delay For Inrush Current Protection
US20110187332A1 (en) * 2010-02-01 2011-08-04 Lutron Electronics Co., Inc. Switching Circuit Having Delay For Inrush Current Protection
US8274240B2 (en) 2010-02-01 2012-09-25 Lutron Electronics Co., Inc. Switching circuit having delay for inrush current protection
US20110222191A1 (en) * 2010-03-12 2011-09-15 Reinhold Henke Two Terminal Arc Suppressor
US11295906B2 (en) 2010-03-12 2022-04-05 Arc Suppression Technologies, Llc Two terminal arc suppressor
US8619395B2 (en) 2010-03-12 2013-12-31 Arc Suppression Technologies, Llc Two terminal arc suppressor
US10134536B2 (en) 2010-03-12 2018-11-20 Arc Suppression Technologies, Llc Two terminal arc suppressor
US11676777B2 (en) 2010-03-12 2023-06-13 Arc Suppression Technologies, Llc Two terminal arc suppressor
US10748719B2 (en) 2010-03-12 2020-08-18 Arc Suppression Technologies, Llc Two terminal arc suppressor
US9508501B2 (en) 2010-03-12 2016-11-29 Arc Suppression Technologies, Llc Two terminal arc suppressor
US9087653B2 (en) 2010-03-12 2015-07-21 Arc Suppression Technologies, Llc Two terminal arc suppressor
US9568005B2 (en) 2010-12-08 2017-02-14 Pentair Water Pool And Spa, Inc. Discharge vacuum relief valve for safety vacuum release system
US9243413B2 (en) 2010-12-08 2016-01-26 Pentair Water Pool And Spa, Inc. Discharge vacuum relief valve for safety vacuum release system
US10465676B2 (en) 2011-11-01 2019-11-05 Pentair Water Pool And Spa, Inc. Flow locking system and method
US10883489B2 (en) 2011-11-01 2021-01-05 Pentair Water Pool And Spa, Inc. Flow locking system and method
US9885360B2 (en) 2012-10-25 2018-02-06 Pentair Flow Technologies, Llc Battery backup sump pump systems and methods
US9302593B2 (en) * 2013-08-02 2016-04-05 Delta Electronics, Inc. Protecting switch contacts of relay apparatus from electrical arcing in electric vehicle
US20150035485A1 (en) * 2013-08-02 2015-02-05 Delta Electronics, Inc. Electric vehicle supply equipment and method of operating the same
US9307622B2 (en) 2014-08-22 2016-04-05 Lutron Electronics Co., Inc. Three-way switching circuit having delay for inrush current protection
US11367578B2 (en) 2016-09-09 2022-06-21 Eaton Intelligent Power Limited Circuit breaker
WO2018046708A1 (en) * 2016-09-09 2018-03-15 Eaton Industries (Austria) Gmbh Circuit breaker

Similar Documents

Publication Publication Date Title
US3558910A (en) Relay circuits employing a triac to prevent arcing
US3783305A (en) Arc elimination circuit
US3555353A (en) Means effecting relay contact arc suppression in relay controlled alternating load circuits
US3662190A (en) Control circuit for single stroke electrical tools
US4155015A (en) Light switch
US3641397A (en) Off-delay solid-state timer systems
US4204128A (en) Adjustable time delay relay
US3406295A (en) Cycling on-off electronic timing system using one relay
US3389301A (en) Arc suppressing circuit
US3754165A (en) Electromagnetically actuated switching device having delayed dropout
US3755695A (en) Solid state motor control cycling timer
US3239722A (en) Electrical control system
US3397323A (en) Timer
US3329838A (en) Capacitor operated scr switching circuit
NL8204140A (en) SWITCHING DEVICE.
US3740585A (en) Power control system
US3401312A (en) Solid state time delay after deenergization function circuit
US3564346A (en) Control circuit
US3483395A (en) Electronic timing circuit
US3715605A (en) Control circuit for single stroke electrical tools
US3758793A (en) Synchronous switching circuit
US3469153A (en) Apparatus for energizing and de-energizing a plurality of switching devices in a predetermined sequence
US3668511A (en) Self energizing tap switch for electronic tap changer
US3809970A (en) Solid state timing circuit
US3562598A (en) Semiconductor controlled safety time delay relay