This circuit was found in the April 1970 Radio Electronics magazine. The dual function circuit uses 4 transistors and is connected to the vehicle's contact breaker.
This circuit was taken from the 1974 Ferranti transistor manual. Transistors are common types at...
This circuit monitors the current of a series of 40 V lithium battery packs connected in series....
This 1970 Philips circuit uses a mechanical counter. The circuit is triggered by a reed switch...