This circuit was obtained from an Electronic Design from the 90's. The circuit generates signals at a frequency determined by R and C. The selection by the jumpers determines the PWM modulation.
This transmitter kicks in when the microphone picks up sound. This sound then modulates the signal...
The great advantage of the circuit shown in the figure is the fact that its frequency is...
This circuit for incandescent lamps was found in the February 1972 Radio Electronics magazine. The triac is...