This circuit was found in Motorola documentation from 1969. The transistors are from that time. The pulses are 200 ns with 500 mA. Observe the high supply voltage.
Found in Radio Electronics from the 90s, this siren finds many variations on this site. The...
This simple diode and transistor tester can also be powered by the 110 V power grid if the...
This circuit was obtained in a magazine Hands On-Electronics from June 1987. It is a circuit that...