Found in old documentation, this circuit uses a double gate MOSFET. The operating frequencies depend on the coil, and the indicator is a microammeter.
This digital pulse counter offers an LED indication. Its maximum frequency is of the order of 5...
This 1960s Signalite circuit uses two SCRs to achieve full wave control. The trigger elements are...
This circuit was obtained from a Popular Electronics. The component is a UJT. The circuit has an...