Found in 90s Popular Electronics, this circuit produces a modulated infrared beam for a remote phone whose circuit is shown right after it. Infrared LEDs are common.
We found this 4-channel mixer in the August 1999 issue of Electronics Now magazine. The circuit can...
The configuration shown makes use of a simple source and the gain is given by the relationship between R3...
This circuit was found in a 1995 documentation and is very simple to assemble, as the components are...