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.
This circuit is from the owner's manual of the integrated circuits used. The manual is old, which...
The UM3562 integrated circuit is a dedicated circuit found in many toys because it generates three types...
This circuit was found in the ON Semiconductor thyristor manual of the 1980s. As the drive is done by...