Found in American documentation from the 90s, this circuit uses a high voltage relay and has no grid isolation. The high values of R1 and R2 prevent the shock when it touches the sensors.
This analog ammeter circuit was found in documentation from the 1980s. The components admit...
This conventional Hartley oscillator circuit with an audio output transformer was found in a...
This bar or moving point indicator (bargraph) employs the LM3914 and can excite 10 LEDs, of any...