Found in a 90s Electronic Design, this circuit employs CMOS functions to mix signals from two inputs. Capacitors and resistors depend on how the signals are to be sampled.
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...