Found in Motorola documentation from the 1970s, this circuit makes use of period components. The lamp is used as a stabilizing device. The signal is sinusoidal.
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...