Wireless Headphones Transmitter Circuit

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 toroidal core T50-2 with 80 turns, 0.2mm Ø. L2 requires a 10-20cm ferrite bar, L2a has 3 turns, 0.6mm Ø coiled at ground end of L2b wich has 30 turns, 0.5mm Ø .The current consumption of the wireless transmitter is <= 150mA and is to be used with this wireless headphones receiver.

Wireless headphones transmitter schematic

Wireless Headphones Receiver Circuit

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 V 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 adjuted with an non metal screw, the reception frequency of this wireless headphone receiver is between 1.7MHz and 3.4MHz – shortwave receiver.

This wireless receiver is to be used with this wireless headphones transmitter.

Wireless headphones schematic