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.
This oscillator was found in a 1976 documentation. The no specified components indicate circuit...
This circuit activates a buzzer when the voltage applied to the input falls below a preset value in...
This protector was found in an Electronics Now from the 90s. The 250 V transient suppressors are common...