This bargraph circuit using LM3914 was found in the October 1980 Radio Electronics magazine. Note the use of a transistor to modify the response.
We found this circuit in the September 1971 Radio Electronics magazine. The SCR can be any of the...
This circuit uses unijunction transistors and drives a small speaker through an output...
The circuit presented was found in the Motorola Linear Databook of 1990. The power supply is...