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 switching power supply was found in an Electronic Design from the 90s. The components are...
This burglar alarm is highly efficient, depending of course on the care with which it is...
This circuit is from a 1969 Electronics World. The transistors may be modern general-purpose...