This multi-output power supply was found in an article in Radio Electronics magazine in November 1985. Voltage regulators must be equipped with heat sinks.
Carbon microphones are no longer used in most projects. However, finding one in the scrap metal, it...
This circuit produces a strong tone of audio or ultrasound, depending on the values of components C1 and...
This alarm from an old 1978 publication uses PNP transistors and driver and output transformers that are...