The resistors R1 and R2 consist of 8 220 ohms x 2 W resistors connected in parallel. The dissipation must be higher for high transmitter power. The indicator can be the multimeter.
August 2017 - STMicroelectronics' new T850 switches with triacs up to 8 A can be obtained from...
Found in a 1967 Electronics World, this circuit can use any modern equivalent FET. Observe the...
July 2017 - Texas Instruments' new bidirectional current controllers LM5170-Q1 for power...