This circuit activates a relay when the supply voltage drops below the value set in the trimpot. The transistors can be the BC548 and BC558 and the 6 V relay. The circuit was found in a 1999 Poptronics.
This small regulator was found in a Motorola 1968’s documentation. It is a current regulator using...
This circuit was found in a 1968 US publication. Transistors used are uncommon today. The circuit...
This electronic bait, or fish attractor, produces a sound in the water that attracts fish of...