July 25, 2009

Simplest Wireless Headphone

11:11 PM  Sabarish  3 comments

Simplest Wireless Headphone
A basic Infra Red Link for audio communication for distances up to 10 feet.

Working
The transmitter comprises a single amplifying stage driving two series connected IR LEDS. The input source is connected to J1. Please note that the device will pass a small DC current through it and also directly bias the transistor. A suitable device is therefore a high output crystal microphone. These can produce high output voltages up to 1 Volt but this will be reduced by the transistors low input impedance.

The receiver is three stages, the first stage being a photo-transistor. Stages two and three form a high gain darling-ton emitter follower, the bias for the whole stage derived through R2 and the photo-transistor itself. C1 and R3 form a filter to reduce interference from fluorescent lighting and other hum sources. The output is via Jack J2. Note also that the output device will pass a small DC current so a medium impedance loudspeaker or headphones are a good choice here.

Circuit Diagram


NOTE : Click the diagram for better Quality.

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3 comments:

Headphones Capital providing Wireless Headphones in australia.

what is the component of Q2?

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Electronics is the study and use of electrical that operate by controlling the flow of electrons or other electrically charged particles in devices such as thermionic valves. and semiconductors. The pure study of such devices is considered as a branch of physics, while the design and construction electronic circuits to solve practical problems is called electronic engineering.

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