IR Remote Control Modulation Detector

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Circuit : Andy Collinson
Email: anc@mitedu.freeserve.co.uk

Description:
A circuit to extract and measure the modulated carrier of an Infra Red remote control. Note that the circuit does not physically separate control pulses from modulation, but amplifies the completereceived signal allowing the waveform to be displayed ideally on an oscilloscope or a frequency counter. Modulation frequencies between 1kHz and several MHz may be measured.

Basic IR Remote Control Info:
All remote controls employing Infra Red technology use digital control signals that are modulated with a higher frequency carrier wave. The carrier wave, which is invisible to the human eye is commonly modulated between 36 and 38KHz. However,some equipment i.e. Satellite decoders may use even higher modulating frequencies. The digital control signals are relatively slow compared to the carrier frequency, typically 100 to 200 bps (bits per second). The control pulses are sent in serial format and turn the carrier on and off.

Read More Source:
http://www.zen22142.zen.co.uk/Circuits/Interface/mod_det.htm

This entry was posted on Monday, October 15th, 2007 at 6:34 pm and is filed under Digital, Electronic Control. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.