This circuit makes use of a low impedance microphone. The relay is according to the supply voltage which can be between 9 and 15 V. The operational gain is approximately 100.
The purpose of this circuit is to emit infrared pulses. However, LEDs for visible light can also...
This circuit, ideal for those who have signal problems in the UHF band, mainly in the reception of digital...
Phase and amplitude can be controlled in this circuit found in the May 1988 Radio Electronics...