The circuit shown indicates voltages from 10 to 14 V used to monitor automotive voltage. One or two LEDs light up depending on the voltage.
This circuit has both frequency and duty cycle control. We found it in the October 1992 Radio...
This power supply is indicated for the supply of not very powerful car radios of the AM and FM...
In the absence of a modulation signal, the carrier of this simple short-range transmitter is cut...