This circuit with 1% regulation aims at replacing mercury cells. We found it in a 1967 documentation. Transistors can be replaced with modern equivalents.
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...