BE1024920B1 - DEVICE FOR CONVERTING AN INPUT VOLTAGE TO INDEPENDENT OUTPUT VOLTAGES - Google Patents

Abstract

According to an embodiment, the invention comprises a recoil converter (150) for converting an input voltage (100) into two independent output voltages (101, 102) comprising a first feedback (130, 131, 123, 117) configured to connect an input switch (115) to control the total electrical power demand of two output portions (106, 107) of the recoil converter (150) and a second feedback to distribute the electrical power across the first (106) and second (107) output portions.

Description

(30) Priority data:

(73) Holder (s):

DANTRONIC private limited liability company

2920, CALMTHOUT

Belgium (72) Inventor (s):

VERHEIJ Peter 2960 BRECHT Belgium (54) APPARATUS FOR CONVERTING AN INPUT VOLTAGE TO INDEPENDENT OUTPUT VOLTAGES (57) According to one embodiment, the invention comprises a flyback converter (150) for converting an input voltage (100) into two independent output voltages (101, 102) comprising a first feedback (130, 131, 123, 117) configured to drive an input switch (115) to meet the total electrical power demand of two output portions (106, 107) of the flyback converter (150) and a second feedback to distributing the electrical power between the first (106) and second (107) output sections.

BELGIAN INVENTION PATENT

FPS Economy, K.M.O., Self-employed & Energy

Publication number: 1024920 Filing number: BE2017 / 0080

Intellectual Property Office

International classification: H02M 1/00 H02M 3/335 Date of issue: 08/09/2018

The Minister of Economy,

Having regard to the Paris Convention of 20 March 1883 for the Protection of Industrial Property;

Having regard to the Law of March 28, 1984 on inventive patents, Article 22, for patent applications filed before September 22, 2014;

Having regard to Title 1 Invention Patents of Book XI of the Economic Law Code, Article XI.24, for patent applications filed from September 22, 2014;

Having regard to the Royal Decree of 2 December 1986 on the filing, granting and maintenance of inventive patents, Article 28;

Having regard to the application for an invention patent received by the Intellectual Property Office on 09/06/2017.

Whereas for patent applications that fall within the scope of Title 1, Book XI, of the Code of Economic Law (hereinafter WER), in accordance with Article XI.19, § 4, second paragraph, of the WER, the granted patent will be limited. to the patent claims for which the novelty search report was prepared, when the patent application is the subject of a novelty search report indicating a lack of unity of invention as referred to in paragraph 1, and when the applicant does not limit his filing and does not file a divisional application in accordance with the search report.

Decision:

Article 1

DANTRONIC private limited liability company, Fransweg 20, 2920 KALMTHOUT Belgium;

represented by

DUMAREY Robrecht, Hubert Frère-Orbanlaan 329, 9000, GHENT;

a Belgian invention patent with a term of 20 years, subject to payment of the annual fees as referred to in Article XI.48, § 1 of the Code of Economic Law, for: FURNISHING

FOR CONVERTING AN INPUT VOLTAGE TO INDEPENDENT

OUTPUT VOLTAGES.

INVENTOR (S):

VERHEIJ Peter, Koekoeksdreef 29, 2960, BRECHT;

PRIORITY:

BREAKDOWN:

Split from basic application: Filing date of the basic application:

Article 2. - This patent is granted without prior investigation into the patentability of the invention, without warranty of the Merit of the invention, nor of the accuracy of its description and at the risk of the applicant (s).

Brussels, 09/08/2018,

With special authorization:

- 1 B E2017 / 0080

DEVICE FOR TRANSFORMING AN INPUT VOLTAGE

TO INDEPENDENT OUTPUT VOLTAGES

Technical Field The invention is situated in the field of electric power conversion and more particularly in the field of flyback converters.

Background Art [02] A device for converting an electric power is already known. A flyback converter, also called a flyback converter, is used to convert an AC or DC voltage, called the input voltage, into an output voltage where input and output voltages are galvanically separated from each other.

[03] In one embodiment, the input voltage is converted to a single output voltage. The input voltage is then connected to an input circuit which is then connected to a coil on the primary side of a transformer. The output chain is then located on the secondary side of the transformer. In the latter chain, a diode is placed and a capacitor parallel to the output chain behind the diode. The output voltage will then be applied to this capacitor. The input circuit further has a switch, called the input switch, which is driven to control the power transfer from the input voltage source to the output voltage. The regulation can, for example, be based on the power demand at the output.

-2BE2017 / 0080 [04] In addition to the above embodiment, a circuit comprising multiple output voltages can further be provided. The supplied power then comes again from a single input voltage source and is distributed over several output chains.

[05] Publication US6130828 thus describes a circuit providing a second output circuit connected to a second secondary output of the coil. This second output chain is separated from the first output chain. The regulation is done by feedback via the first output chain. A drawback of this solution is that a power demand in the second output chain can cause a voltage drop in the first output chain. Consequently, there is a dependence between the two output chains, which however cannot be matched.

[06] The circuit disclosed in patent publication US6504027B1 also includes multiple output circuits. The feedback is based on the sum of the power demand of the different outputs and the power is distributed via a control circuit that controls a switch per output chain. However, this circuit also has some drawbacks. Just as in the circuit described in US6130828, a switch can be switched while it is still live. This not only creates switching losses, but also requires the switches to be sized to interrupt a current in the middle of a current cycle. It is also a drawback that a switch must be provided for each output chain. This not only increases the cost of such a circuit, but also increases the complexity of the feedback circuit to drive power demand to the input circuit on the one hand, and to control its distribution across the different output circuits on the other.

[07] Accordingly, there is a need for a device to convert an input voltage to independent output voltages while overcoming the above-mentioned drawbacks.

-3BE2017 / 0080

Summary of the Invention It is an object of the present invention to provide a means to efficiently and easily convert an input voltage to independent output voltages.

[09] This object, according to a first aspect of the invention, is achieved by providing a flyback converter for converting an input voltage into a first and a second output voltage, the flyback converter comprising:

a transformer comprising a primary input and a first and second secondary output; and

an input section comprising a voltage input for applying the input voltage and an input switch configured to interrupt a power supply from the voltage input to the primary input; and

- a first and second output section connected to the first and second secondary output, respectively, and configured to supply the first and second output voltage, respectively, through a first and second voltage output, respectively; and wherein the second output portion includes an output switch to interrupt power supply from the second secondary output to the second voltage output; and

- a first feedback configured to drive the input switch based on a sum of deviations in current and / or voltage at the first and second voltage output from a desired current and / or voltage at the first and second voltage output so that the input portion a power supply that compensates for the sum of the deviations; and a second feedback configured to drive the output switch based on a difference of the deviations in current and / or voltage so that power supplied by

-4BE2017 / 0080 the first feedback is divided between the first and the second output part, which compensates for the difference of the deviations.

[10] The transformer includes, for example, magnetically coupled coils with one primary input and two secondary outputs, but it can also consist of a converter that converts an input voltage into two output voltages. The flyback converter also has an input circuit to which the input voltage source is connected. This voltage is, for example, a periodic electrical voltage at an industrial mains frequency, such as 50 or 60Hz, but can also be a DC voltage source. The input circuit further has an input switch to interrupt the electrical power supply from the source to the transformer.

[11] The flyback converter has two output sections, each connected to the first and second secondary outputs of the transformer or converter, respectively. The independent voltages are then supplied through a first and second voltage output, each provided at the first and second output sections, respectively.

[12] One of the output sections includes an output switch, for example the second output section. This switch is configured to interrupt the power supply from the transformer to which the output section with the switch is connected to the voltage output.

[13] Furthermore, the circuit of the flyback converter has a first feedback. This feedback controls the switch of the input section based on the sum of the deviations in current and / or voltage with respect to the desired value thereof, so that a power is supplied from the input section to compensate for these deviations. In other words, the input switch becomes

-5BE2017 / 0080 controlled on the basis of the sum of the power demand of both output parts.

[14] Finally, the flyback converter includes a second feedback that drives the output switch. This control is based on a difference of the deviations in current and / or voltage with respect to the desired value thereof, so that the power is divided over both output parts. In other words, the output switch is driven on the basis of the distribution of the power over the first and second output section.

[15] So both feedbacks are driven on the basis of measured deviations in current and / or voltage at the two output parts. It is therefore an advantage that both feedbacks occur by taking one measurement per output section. This limits the number of components in the circuit while driving both switches independently. Another advantage is also that only one switch is needed for both output parts to distribute the power over both. This limits any switching losses and the required power components.

[16] In one embodiment, the flyback converter further comprises a memory element configured to synchronize the interrupting of the input switch and the output switch.

[17] The total power demand can change over time, while in the same period the mutual distribution between the output parts also changes. By synchronizing the interrupting or switching of both switches, ripples in the voltages resulting from these circuits are minimized. This has the advantage that the output voltages are more stable and a negative influence on the operation of devices connected thereto is limited.

-6BE2017 / 0080 [18] According to an embodiment, the memory element comprises a signal input, signal output and control input, wherein;

- the signal input is connected to the output of the second feedback; and

- the signal output is connected to the output switch; and

- the control input is coupled to the first or second secondary output; and wherein the control input is configured to control the memory element based on a change in voltage in the first or second secondary output.

[19] The memory element is, for example, a bistable multivibrator, also known as a flip-flop. This flip-flop is placed between the second feedback and the output switch. Furthermore, it is driven based on a change in voltage in the first or second secondary output.

[20] The advantage of the memory is not only that a simple and known component is used to synchronize the interrupting of the input and output switch, but also that the output switch will only switch when it is not powered by the control input changing. measure voltage. This limits the switching losses to a minimum and the switch of the second feedback should not be sized to interrupt large current values. This reduces the cost of the recoil converter.

[21] According to an embodiment, the first and second output parts respectively comprise a differential amplifier configured to measure the deviation in current and / or voltage at the first and second voltage output, respectively. The differential amplifier or op amp is used to measure even a small variation in the current and / or voltage.

-7BE2017 / 0080 [22] The differential amplifier in the first output section can be further configured to measure the first output voltage to measure a voltage deviation. Furthermore, the differential amplifier in the second output section can be configured to measure the deviation in current at the second voltage output. According to an embodiment, this can be done, for example, with the aid of a shunt resistor.

[23] In addition, one or both differential amplifiers in the output sections can measure a deviation in voltage and / or current based on the measured voltage and a first and second reference voltage, respectively. As a result, the values of the output voltages are not only determined by, for example, the transformation ratio in the coil, but they can be further adjusted by the first and / or second reference voltage. These reference tensions, in turn, can also be adjustable in order to have great flexibility.

[24] The flyback converter may further include an optocoupler configured to drive the input switch. In this way there is then a completely galvanic separation between the input part and both output parts.

[25] According to an embodiment, one and / or both differential amplifiers in the first and / or second output section further comprise an integrator circuit. This measures the deviation of the voltage and / or current over time. The advantage is that small fluctuations are not immediately anticipated, but averaged over time. This provides a more stable operation of the flyback converter and consequently a more stable value of the output voltages.

-8BE2017 / 0080

Brief Description of the Drawings [26] The invention will now be further described with reference to the drawings, in which:

[27] FIG. 1 schematically shows a flyback converter to convert an input voltage to two independent output voltages according to an embodiment of the present invention; and [28] FIG. 2 schematically shows a flyback converter comprising various interconnected electronic components according to an embodiment of the present invention.

Description of Embodiments [29] Figure 1 schematically shows a flyback converter 150 configured to convert an input voltage source 100 to two independent output voltages V _ou ti 101 and V _ou t2 102 according to an embodiment of the present invention.

[30] The flyback converter 150, also known as the flyback converter, has an input portion 105 to which the input voltage source 100 is connected. This input voltage source 100 is, for example, a direct current or an alternating current at an industrial mains frequency, such as 50Hz or 60Hz. Furthermore, the input portion 105 includes an input switch 115 and a primary coil 111 of a transformer 110. Over the coil 111 is placed the input voltage 100 which is then transformed into two voltages on the secondary side of the transformer 110: a voltage across a first secondary coil 112 and a voltage across a second secondary coil 113.

-9BE2017 / 0080 [31] The voltages on both secondary coils 112 and 113 are determined by the transformation ratio between the coils in transformer 110.

[32] The flyback converter 150 further has two output sections each comprising a secondary coil. For example, the first output portion 106 includes the secondary coil 112 and the second output portion 107 includes the secondary coil 113.

[33] Each output section further includes a diode with the diode connected to the secondary coil. Thus, the diode 120 in the first output portion 106 is connected to the secondary coil 112 and the diode 121 is connected to the secondary coil 113 of the second output portion 107. Each output portion further includes a capacitor interposed between the diode and the other terminal of the secondary coil . In the output section 106, capacitor 109 is connected to the diode 120 and to the second connection of the secondary coil 112. Capacitor 108 is connected in a uniform manner in the output section 107. The capacitors then have the independent output voltages: over capacitor 109 the first independent output voltage V _ou ti 101 and over capacitor 108 the second independent output voltage V _ou t2102.

[34] The flyback converter 150 further includes an output switch 116 disposed in one of the two output portions and between a diode and a capacitor thereof. For example, Figure 1 shows schematically that the output switch 116 is placed in the second output portion 107 and can interrupt the connection between diode 121 and capacitor 108.

[35] The flyback converter 150 further includes two feedbacks: a feedback for controlling the total power demand of the two output parts 106 and 107 and a second feedback for the

-10BE2017 / 0080 control of the power distribution over these output parts 106 and 107.

[36] For both feedbacks, the voltages across and / or currents are measured by the secondary outputs 101 and 102, respectively. This is schematically represented in Figure 1 by components 130 and 131, respectively, which perform these measurements.

[37] The first feedback is configured to drive input switch 115 based on measured voltages and / or currents through components 130 and 131. This is done by comparing this per measured voltage and / or current with a desired value and this per output section. Both deviations are then summed, for example by a summator 123. The summed value then controls the input switch 115 via a control unit 117. The input switch 115 is generally driven at a switching frequency between 50 to 150 kHz.

In other words, the first feedback ensures that the total electrical power required for both output portions 106 and 107 is supplied from the input voltage source 100.

[39] The second feedback will also drive a switch based on the measured voltages and / or currents through components 130 and 131, in this case the output switch 116. Here the feedback is based on the difference of the deviations in current and / or or voltage relative to a desired value such that the total delivered power driven by the first feedback is divided over the first 106 and second 107 output portions via the second feedback.

[40] For example, the difference between the voltages and / or currents measured by components 130 and 131 is calculated by a differentiator

-11 BE2017 / 0080

124. The differentiator 124, in turn, controls a second control unit 118 which controls the interrupting of the output switch 118. Again, this generally happens at a switching frequency between 50 to 150 kHz.

[41] As a result of both feedbacks, the input voltage 100 is converted into two independent output voltages 101 and 102.

[42] Figure 2 shows a flyback converter 250 according to an embodiment of the present invention with further detailing of electronic components that can be used for the first and second feedback.

[43] In Figure 2, identical to Figure 1, the input voltage source 100 is again shown, as is the input switch 115, the output switch 116, the transformer 110 comprising the primary coil 111, the two secondary coils 112 and 113, the capacitors 108 and 109 and diodes 120 and 121.

[44] The flyback converter 250 in Figure 2 further includes an operational amplifier 200 and a shunt resistor 212. This operational amplifier 200 and shunt resistor 212 correspond to component 131 of Figure 1 to measure, in this case, a current through the circuit in the circuit. second output section 107. Furthermore, this component includes a controllable DC voltage source 210. This controllable DC voltage source 210 serves to set the desired value of the output voltage 102, which in turn determines a desired current in the second output section 107. This output voltage is shown in Figure 2 as a potential difference between points 232 and 233.

[45] For example, light-emitting diodes 251 can be connected to this second output section 107.

-12BE2017 / 0080 [46] The component 130 in Figure 1 corresponds to the operational amplifier 201 and the voltage source 211 in Figure 2. The operational amplifier 201 measures the output voltage 101 of the first output portion 106 which is represented in Figure 2 by the potential difference between points 230 and 231. In series with the operational amplifier, a DC voltage source 211 may be placed to set the desired value of the output voltage 101 by a controllable or fixed voltage source.

[47] The deviations in current measured in the second output section 107 and voltage measured in the first output section 106 are summed by summator 206. This summator then controls the control unit 211 to control the interruptions of the input switch 115.

[48] According to an embodiment of the invention, an opto-coupler 234 is placed between summator 206 and control unit 221. This provides a galvanic separation between the input section 105 on the one hand and the two output sections 106 and 107 on the other.

[49] In the second feedback, the difference between the measured deviations of the current in the second output section 107 and the measured deviations of the voltage in the first output section 106 is measured by the differential amplifier 207. This differential amplifier then controls the interrupting of the output switch 116. On.

According to an embodiment of the invention, a memory element is placed between the differential amplifier 207 and the output switch 116 to synchronize the switching of the input switch 115 and the output switch 116.

- 13BE2017 / 0080 [51] In Figure 2, this memory element is schematically represented by flip-flop 202. The flip-flop 202 has a signal input 205 to which the differential amplifier 207 is connected and a signal output 203 which is connected to the output switch 116. The control input 204 of the flip-flop 202 is then connected to the coil 112 of the secondary side of the transformer 110. With a negative edge of the voltage on the secondary side, the flip-flop 202 is triggered. This not only synchronizes the interrupting of the input switch 115 with the output switch 116, but further ensures that the output switch 116 does not interrupt the circuit in the second output portion 107 when current flows through it.

[52] According to an embodiment of the invention, the differential amplifiers 200 and 201 may further comprise an integrator circuit. As a result, the measurement is averaged over time, making the regulation more stable.

[53] Depending on the application of the flyback transducer 250 and the type of net it is placed in, points 230 and / or 232 and / or 234 can be grounded.

[54] Although the present invention has been illustrated by specific embodiments, it will be apparent to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be practiced with various modifications and adaptations without leaving the scope of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being described by the appended claims and not by the foregoing description, and any changes falling within the meaning and scope of the claims, are therefore included here. In other words, it is assumed that below all changes,

-14BE2017 / 0080 variations or equivalents that fall within the scope of the underlying basic principles and whose essential attributes are claimed in this patent application. In addition, the reader of this patent application will understand that the words comprising or including do not exclude other elements or steps, that the word excludes a plural, and that a simple element, such as a computer system, a processor or other integrated unit, performs the functions of different be able to fulfill the tools mentioned in the claims. Any references in the claims should not be construed as limiting the claims in question. The terms first, second, third, a, b, c and the like, when used in the description or in the claims, are used to distinguish between similar elements or steps and do not necessarily describe a sequential or chronological order. Likewise, the terms top, bottom, over, bottom and the like are used for description and do not necessarily refer to relative positions. It is to be understood that those terms are interchangeable under the appropriate conditions and that embodiments of the invention are capable of functioning according to the present invention in other sequences or orientations than those described or illustrated above.

-15BE2017 / 0080

Claims (13)

CONCLUSIONS A flyback converter (150) for converting an input voltage (100) into a first (101) and a second (102) output voltage, the flyback converter (150) comprising: - a transformer (110) comprising a primary input (111) and a first (112) and second (113) secondary output; and - an input section (105) comprising a voltage input for applying the input voltage (100) and an input switch (115) configured to interrupt a power supply from the voltage input to the primary input (111); and - a first (106) and second (107) output portion connected to the first (112) and second (113) secondary outputs, respectively, and configured to supply the first (101) and second output voltage (102), respectively, through a first and second voltage output; and wherein the second output portion (107) includes an output switch (116) to interrupt a power supply from the second secondary output (113) to the second voltage output; and - a first feedback (130, 131, 123, 117) configured to drive the input switch (115) based on a sum of deviations in current and / or voltage at the first and second voltage outputs from a desired current and / or voltage at the first and second voltage outputs so that the input portion (105) provides a power that compensates for the sum of the deviations; and - a second feedback (130, 131, 124, 118) configured to drive the output switch (116) based on a difference of the deviations in current and / or voltage so that power is generated by the first feedback over the first (106) and the second (107) output portion is divided which compensates for the difference of the deviations. -16BE2017 / 0080 The flyback converter (150) of claim 1, further comprising a memory element (202) configured to synchronize the interrupting of the input switch (115) and the output switch (116). A flyback converter (150) according to claim 2, wherein the memory element (202) comprises a signal input (205), signal output (203) and control input (204); and where - the signal input (205) is connected to the output of the second feedback (130, 131, 124, 118); and - the signal output (203) is connected to the output switch (116); and - the control input (204) is coupled to the first (112) or second (113) secondary output; and wherein the control input (204) is configured to control the memory element (202) based on a change in voltage in the first (112) or second (113) secondary output. A flyback converter (150) according to any preceding claim, wherein the first output portion (106) comprises a differential amplifier (201) configured to measure the deviation in current and / or voltage at the first voltage output. A flyback converter (150) according to claim 4, wherein the differential amplifier (201) is configured to measure the first output voltage (101) such that the differential amplifier (201) measures the voltage deviation at the first voltage output. A flyback converter (150) according to claim 5, wherein the differential amplifier (201) is configured to measure the voltage deviation based on the measured voltage and a first reference voltage (211). - 17BE2017 / 0080 A flyback converter (150) according to any preceding claim, wherein the second output portion (107) comprises a differential amplifier (200) configured to measure the deviation in current and / or voltage at the second voltage output. The flyback converter (150) of claim 7, wherein the differential amplifier (200) is configured to measure the second output voltage (102) such that the differential amplifier (200) measures the deviation in current at the second voltage output. The flyback converter (150) of claim 8, wherein the second output portion (107) includes a shunt resistor (212) and the differential amplifier (200) is configured to measure the voltage across the shunt resistor (212) so that the differential amplifier (200) deflects the deviation in current at the second voltage output. The flyback converter (150) of claim 9, wherein the differential amplifier (200) is configured to measure the deviation in current based on the measured voltage and a second reference voltage (210). A flyback converter (150) according to claims 6 and 10, wherein the first (211) and / or second reference voltage (210) is an adjustable voltage. A flyback converter (150) according to any preceding claim, wherein the first feedback (130, 131, 123, 117) further comprises an optocoupler (220) configured to drive the input switch (115). A flyback converter (150) according to any preceding claim, wherein the differential amplifier in the first and / or second output portion further comprises an integrator circuit. - 18BE2017 / 0080 150 I -19BE2017 / 0080 t \ l * , ox LL -20BE2017 / 0080