This circuit is from an old American documentation and its use in motorcycles with 12 V is suggested to power 6V radios. The transistor can be the BD136 and BC548.
This circuit, from ancient French documentation, produces a rectangular pulse from input pulses...
This timer for small intervals, but which can be increased with the increase of R1, was obtained in an...
Found in a 90s Radio Electronics, this circuit can supply currents of a few amps, according to the power...