This circuit is from a Fairchild digital clock module shown in the March 1977 issue of Radio Electronics magazine. The circuit required a few external elements, including a common transformer.
This small audio amplifier was found in the May 1994 issue of Electronics Now magazine. The power...
The displayed relay operates with an audio signal applied to the input. The transistors can be...
The circuit shown in the figure and uses the diode in the leakage current operation mode. In it,...