This circuit is for 12 V batteries but can be used with batteries of other voltages by changing the zener diode. The trigger point is adjusted by R1. The operating system accepts equivalents.
In the figure we have the transmitter of a data transmission system with optical fiber suggested by...
This circuit was found in a 1969s American documentation. With modern components, it can be used...
The maximum input voltage of this circuit is 20V and the output current is 250 mA. The circuit is from...