GB983377A - Improvements relating to the reserve fuel supply for road vehicles - Google Patents

Abstract

983,377. Fuel supply systems. J. C. RIDOUT, and W. F. HILL. Feb. 5, 1964 [Nov. 6, 1962], No. 41851/62. Heading F1B. The reserve fuel supply of a vehicle is provided with a control tap or valve which after being moved to its reserve position is automatically returned to its normal position when the ignition or a vehicle immobiliser which is subsequently closed. The circuit in Fig. 1 comprises a battery D, ignition switch E, reserve tap solenoid C, reserve button switch B and "avalanche diode" A, Shockley diode or combination of Zener diode and rectifier. With ignition switch E closed, pressing of button B energizes solenoid C to bring in the reserve fuel supply and then on release of button B the inductive surge voltage generated by solenoid C causes breakover of device A from the non-conducting to conducting state thus providing a current supply to solenoid C to maintain the reserve fuel supply until the ignition switch E is opened when the diode A returns to its high resistance state. A small condensor H or ferrite beads on the wiring to protect the device A from electrical interference and an indicator lamp G may be provided. In a modification (Fig. 2, not shown) switch B is replaced by a switch which acts as switch B when pressed but when withdrawn breaks the circuit between switch E and device A hence cutting off the reserve fuel supply. Alternatively the reserve tap is operated by a solenoid with a 'hold on' contact which is energized either directly or through a relay when the reserve switch is operated. A mechanical coupling may alternatively be provided between the ignition switch and either a reserve switch or manual reserve tap which incorporates a latch releasable by opening of the ignition switch.