Patent GB-1350705-A (GB)
Title: Lock and power control circuit for automotive vehicles and the like
IPC: B60R25/10
Filed: 1972-03-22
Abstract: 1350705 Locks WAGNER ELECTRIC CORP 22 March 1972 [24 March 1971] 13337/ 72 Heading E2A [Also in Division G4]  An electronic circuit for controlling a door lock V and the power control circuit VII of a vehicle, comprises a tank circuit L1, C2 which is responsive to the juxtapositioning of a key circuit, Fig. 2, to suppress its resonance, to thus release the lock of at least one door by means of solenoid SOL1, and at the same time the control circuit enables the engine to be started if starting switch S8 is closed during the charging period of condenser C10, and it also serves to switch off the engine and release the door locks when switch S7 is momentarily operated to open its upper contact. In detail, the circuit operates as follows: On closure of a key-operated switch S1, power is fed to the oscillator I. This is rectified at II, and amplified at III and IV. In this last stage, a transistor Q4 is maintained normally conductive thereby earthing the base of transistor Q5 to make it non-conductive. This prevents energisation of relay K1. However, when the key circuit is placed in position, the base of transistor Q5 is energised, enabling current to reach relay K1 to operate its contacts. This lights an indicating lamp I1 and current passes to the power control circuit VII, and through N.C. test switch S2 and capacitor C9 to momentarily energise relay K2 and the unlocking solenoid SOL1 (and the locks of other doors, if desired). The locking solenoid SOL2 and the unlocking solenoid SOL1, may be controlled by a two-position switch S3. A door-switch S5 may operate a warning at D4 and feeds (when the door is open) a delayedpulse generating circuit comprising a diode D13 charging a capacitor C12 to operate relay K6 to unearth the emitter of transistor Q7. Simultaneously a charge timing capacitance C13 is charged. Hence when the door is closed, the opening of switch S5, causes discharge of current through relay K7 to momentarily close it to energise the locking relay SOL2, and so lock the door. Other door circuits VI may function similarly. The power control circuit VII receives current from relay K1 to charge condenser C10 which then discharges through the base and emitter of transistor Q6 over 30-40 seconds. Consequently a relay K3 will be energised during this period, lighting a lamp 12 and disabling alarm circuit VIII by biassing transistor Q9 through diode D17, so that the horn does not sound when the operator actuates starting switch S8 to energise relay K5. This energises relay K4 through thyristor TH1 to energise the ignition circuit, and it also energises the starting motor. To stop the engine, the operator momentarily opens the upper contact of switch S7. This cuts off the thyristor to cut off the ignition current, and it also energises relay K2 to momentarily energise relay SOL1 to unlock the driver's door. To restart the engine once capacitor C10 has discharged, it will be necessary to use the key circuit to initiate the whole sequence of events to energise relay K3. If the starting switch S8 is energised while the relay K3 has not been energised by the key, no disabling voltage is applied to transistor Q9 and the horn will sound, and this way be latched in action. The key circuit may include a resistor, as shown in Fig. 2, or the inductance L1 may be split into two series sections (Fig. 3, not shown).