This circuit was found in a 1980s US publication. It indicates when the phone is off-hook by triggering an indicator.
This circuit was suggested by a Radio Shack publication from the 1980s. The purpose of this...
The idea is simple: using a flashlight to cut your TV commercials triggers a relay that turns off...
April 2017 - Mouser Electronics already stocks the new Broadcom APDS-9500 proximity and gesture...