This circuit provides a reference voltage of 2.5 V adjusted in the trimpot. The transistor can be the BC558 (in the drawing it came out as NPN). The control is done by a rectangular input signal.
This circuit can operate with 5 uV to 1 mV input signals from low impedance sources such as...
This very simple circuit with neon lamps indicates who pressed the button first, lighting the...
This circuit was originally designed for the practice of Morse code, something common in 1966, the year...