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 circuit is from a 1967 publication. It is possible to power a fluorescent lamp from a 12 V...
This circuit was found in old American documentation. Transistor is general purpose and coil rated...
With a strong positive feedback (via a 10 M resistor) we can get the trigger setting for the...