This circuit, obtained from a 1965 magazine, can still be assembled using some modern equivalent components. The transistors may be BC558 and the transformer is obtained from a disused transistor radio.
We found this circuit in an old English documentation from the 70s. The transistor can be a modern...
We find the circuit below in the 1994 Linear Applications Handbook by National Semiconductor. The...
January 2017 - Omron G7L-x relays for PCB mounting can now be purchased from Mouser Electronics. These...