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.
This circuit is from an Argentine publication from 1973. It provides a signal to an amplifier from...
This filter was obtained from the Texas Instruments Linear Circuits Applications. It makes use of...
We found this circuit in a 1997 documentation. It can be used in any common 12 V source and has...