This LED diode test is suggested by the Texas Instruments optoelectronics manual. The transformer current can be between 50 mA and 300 mA and the voltage between 6 and 9 V.
This circuit was found in the March 1979 issue of Radio Electronics magazine. Integrated circuits must...
This is the transmitter for a remote-control system published in the August 1986 issue of Radio...
The current drained by this circuit, from a 1976 documentation, is 3 mA and the cut-off frequency is...