This circuit for car engine spot adjustment was found in an 80's Radio Electronics. The circuit makes use of a xenon lamp and the pulse transformer must have a turn ratio of 1:50.
Relays from 20 mA to 200 mA can be driven by this sensitive circuit.6 or 12 V relays can be used...
This is a conventional double T oscillator, where the frequency is determined by the double T...
This circuit can be used to recognize a tone by its frequency. When this tone is present in a...