Transmitters
Small TV transmitter
This small video transmitter is very usefull for video surveillance on short distances ( up to 100m ) equipped with a black and white or infrared camera module it delivers excellent pictures on a standard color or b/w tv.
Instead of BFY90 you can use any VHF NPN transistor and instead of BC550 any NPN transistor.
Wireless headphones transmitter circuit schematic
This wireless headphones transmitter assures a quality reception over 2 meters. The oscillator frequency is between 1750KHz and 3500KHz and for antenna we use a ferrite bar. IC1 amplifies the audio signal and TC1 is a buffer. D1 signals that the transmitter is on and is a voltage stabilizer for the oscillator .
L1 is a [...]
Wireless headphones receiver circuit schematic
The wireless headphones receiver presented is an standard application of ZN415 produced by Ferranti ( short wave receiver ). ZN415 assures a quality reproduction, has a 1.5 battery alimentation and contains a MA detector and audio amplifier.
The current consumption is < 5mA, L1 has 40 turns, 0.2 Ø copper and 20mm Ø ferrite. C1 is [...]
