This circuit was found in the January 1999 issue of Electronics Now magazine. The circuit uses an integrated circuit from the period and has earphone listening.
This simple circuit controls the signal amplitude through a photoresistor optical coupler. The...
In the figure we have the way to obtain the Exclusive-OR function with 1 transistor. The circuit...
This circuit uses as an indicator a common micrometer type VU with 200 uA of full-scale current. The...