This circuit is from the 80's but uses common components today. The relay is voltage sensitive according to the power supply used. Transistors may be general purpose types.
This small 3 transistor transmitter was found in an English publication from 1963. The coils must...
We found this circuit in a 1980s Motorola documentation. The circuit makes use of common operating...
This Power supply sources from 500 to 1,000 mA according the transformar and was found in a...