This circuit divides the frequency of a 2 kHz signal by 2. The circuit was found in Philips documentation from 1964. Modern transistors can be used for higher frequencies.
This circuit was obtained from an American documentation from the 1980s. The T1 triggering...
This circuit triggers producing a loud sound when a change in temperature is detected. The circuit...
This circuit was found in a 1976 documentation. It can be used with old tape recording mechanisms for...