This circuit was found in the June 1995 Electroics Now magazine. The relay should be a sensitive type with up to 100 mA trigger current.
We present a circuit formed by six voltage comparators. Each comparator will analyze the voltage...
This circuit can generate time base signals from 5 to 1500 Hz. We find it in a documentation about old neon...
In this circuit the CA3140, an operational amplifier, is used as a comparator with the zener diode...