This circuit was found in the July 1994 issue of Electronics Now magazine. The relay can be rated at up to 12 V and 100 mA. The transistor is a general purpose transistor.
This circuit was found in November 1984 Radio Electronics magazine. The frequency is given by C1...
This circuit is built around a component that is not very common today. It consists of a precision...
This is an improved version of the previous circuit also found in the December 1990 Radio...