This circuit was found in a 1970 American publication. The FETs are power types according to the desired output current. The operational can be replaced for modern equivalents.
This circuit triggers the LED when the monitored battery voltage drops below 9 V for 12 V...
Suggested by National Semiconductor, this circuit can be applied to almost any operational...
This circuit was found in Radio Electronics from the 90s. The circuit can generate signals up to...