We found this circuit in the October 1987 Radio Electronics magazine. The triac must be controlled according to the heater. The transformer has a low current, of the order of a few hundred mA.
The circuit shown in figure uses a photodiode as a sensor element and its main feature is to have...
This low power circuit for the FM band was found in a spy book from the 90s. The tunnel diode is...
The transmitter we have described, operates at a frequency between 88 and 98 MHz, with a range of the...