This circuit was found in an article in Electronics Now magazine from March 1997. The transistors are general purpose, and the indicator is a 1 mA full scale analog type.
What is a dual frequency generator for? There are several possibilities of use for this circuit. The...
The circuit, illustrated in the figure, consists of the direct application of the ULN2003 in which...
This circuit was found in a Popular Electronics from the 90's. The output signal can be applied to a...