Found in 1967 General Electric documentation this circuit uses a PUT and a diac to generate 1 kHz signals. The circuit has a start switch.
If the input voltage falls below 12 V the LED glows up. Other voltages can be monitored by...
Found in an old Popular Electronics, this circuit warns when a remote lighting system is not...
This generator is more complete than the previous one, being able to generate pulses as indicated...