Based on the CA3140 IC, this circuit was found in the June 1986 issue of Radio Electronics. Sensitivity adjustment is made using a trimpot in series with the sensor.
This 2000 circuit can work with one of the many infrared remote-control transmitters described in this...
This receiver for listening on the phone was found in a Japanese magazine in 1967. The circuit uses...
The circuit shown in the figure is suggested by Intersil (www.intersil.com) and makes use of the...