We found this circuit in a Popular Electronics from the 90s. It operates at a frequency of 15 kHz. Components can be difficult to obtain, such as the integrated circuit.
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...