MAKE YOUR OWN EMERGENCY POWER PLANT

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Additionally, a DC voltmeter is grounded through one of the ammeter terminals... but requires a 150k-ohm resistor to multiply its existing 0- to 15-volt scale by a factor often. Also, a solenoid vacuum switch (normally open) taken from an eight-cylinder Jeep is wired in parallel with the 1,000-watt resistor coils.

The plumbing's been added to provide vacuum to a choke pulldown diaphragm snitched from a Motorcraft two-barrel carburetor. In conjunction with the Jeep's solenoid- operated vacuum switch and an aquarium air-supply valve, this sweet feature allows remote-control operation that's adjustable to suit a particular job. Put another way, the vehicle's engine will remain at normal idle speed until there's a demand on the system of 100 watts or so (prompted at the moment a tool or appliance is switched on). Then, as current passes through the resistor, the parallel-wired solenoid "borrows" enough to kick the open valve closed... activating the pulldown diaphragm and speeding up the engine by means of a beaded chain fastened to the throttle lever with a miniature collar clamp.

(The one drawback of this inexpensive remote-control setup is that as current demand increases, the resistor element gets warmer... diverting excess voltage to the solenoid, which could cause it to fail over an extended period. To circumvent this possibility, we've included in our design an optional switch that cuts both the resistor and the solenoid-operated vacuum switch out of the circuit so that heavy-duty tools or appliances can be used as long as the alternator maintains its output. An air control valve placed in the solenoid vacuum line allows engine speed to be controlled manually.)

The adjusting screw on the rear of the choke pulldown device provides an upper limit which can be used to preset maximum RPM and, thus, voltage. Similarly, the aquarium valve can be used to fine-tune output below that limit by decreasing the vacuum pull on the suction-sensitive diaphragm. Also, to prevent the diaphragm from yanking the throttle open too quickly and causing hesitation, the exposed inlet of the aquarium valve should be soldered shut, then redrilled with a No. 68 (.031") bit, to allow a small amount of buffering air bleed.

Naturally, when the remote power system is switched off, it doesn't interfere with the charging circuit or the foot-operated throttle. And when the aquarium valve is closed completely, the calculated vacuum leak is eliminated for normal driving.

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