Found in American documentation from the 1980s, this circuit prolongs the ringing of a doorbell or chime powered by a 6 V continuous voltage. The transistor can be a BD136.
This 80's Motorola circuit can generate 100 MHz signals, but they can reach 200 MHz with the...
Of course, the current is extremely small, but a voltage of 300 V can be obtained from 9 V of a...
We found this solid-state relay circuit that can function as a shield in a Radio Electronics...