This circuit was obtained in an old Elektor and can be adapted to use white power LEDs. The transistor must be equipped with a heat sink. The circuit has a battery charger.
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...