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 simple Philips circuit from the 1960s can use any general-purpose transistor. The signal is...
A VCO or voltage-controlled oscillator, which uses only two of the LM3900 amplifiers, is shown in the...
This circuit was found in a British documentation from 1969. It can be implemented with modern...