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.
The simple transistor test shown in the figure can be powered by a 9V battery. The test is for...
This small amplifier, close to 1 W, was found in a 1963 documentation. The class B circuit uses...
The circuit shown in the figure uses 2 of the 4 NAND gates of a 4011 and is designed to produce short...