Found in an Electronics World of 1968 this circuit can use current SCRs and the diodes are according to the lamp. The Circuit only works with incandescent lamps.
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...