GB1337356A - Electrical control apparatus for an engine and variable trans mission apparatus - Google Patents

Abstract

1337356 Regulating I.C. engines TWIN DISC Inc 7 Jan 1972 [13 Jan 1971] 775/72 Heading F1B [Also in Divisions F2 G1 G3 and H2] A control for the throttle-governors of one or more engines on a marine vessel or off highway vehicle, and operable from a master station 6 or remote stations 7, 8 comprises a throttle lever 18 at each station, operating the throttle governor through an electrical correspondence control operating in response to voltage between a centre tap 141, Fig. 6, (not shown) and a slide tap 143 of a potentiometer 35, receiving a constant voltage across its ends, the slide-tap 143 being operated by a 120 degree movement of the throttle lever. The centre tap lead 141 forms one non-inverting input to an operational amplifier 155, Fig. 9, the other input 157 of which, the slide tap lead 143, is connected to the input line 157 through contacts 93-7 &c of a transfer relay 93, Fig.7 (not shown) which selects which of the station potentiometers is to be in circuit. The centre-tap lead 141 is also applied as a non-inverting input to a second operational amplifier 155, the other input of which is the output of amplifier 154, both amplifiers being connected through an H-connected servo amplifier, with a Darlington quad connection 158, 160, the final output 159, 161 feeding the energizing winding of a permanent magnet motor 146, which actuates the throttle through 70 degrees total movement, as limited by switches 174, 175 which open to insert a resistor 173 in the circuit 150 (see below) to prevent excess torque when the motor is positively stopped. The motor-operated tapping of a potentiometer 149 feeds back through an adjustable potentiometer 156 to the inverting input of the amplifier 154 for positioning the throttle in accordance with the desired scales of movement as determined by the error signal output of the amplifier 154. The power supply to this circuit is regulated to a lower level (15v) than that (24v) of the main supply 80 and has a current limiter 150. Voltage is regulated by a Zener diode 164 and a Darlington pair 166, with a voltage-sensing branch 167 including a potentiometer 168, transistor 165 and temperature-compensating diode. The currentlimiter includes another Zener diode 170 and transistor 169. Engine shut down can be made at the master control 6 only, by a switch 16, which, in the case of engines requiring a 20 degree negative range below idle for shut down, is provided by an auxiliary motor Fig.11, (not shown) coupled to a second control shaft of the throttle governor. Limit switches thereon re-set the throttle to idle following shut-down.