Suggested by a Philips documentation from 1970, this circuit uses period components, operating at 50 Hz. The current consumed is 10 A and the input voltage is 12 V.
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...