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how does a PULSE code MODULATION WORKS?

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leonheard

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how does a PULSE code MODULATION WORKS?
« on: April 07, 2013, 10:33:33 AM »
how does a PULSE code MODULATION WORKS?


When I press a button in my IR transmitter it will send binary codes example.
1 1 1 0 with a 38 KHZ carrier.

The IR receiver device will detect the 38 KHZ ( with the filtered code, 1 1 1 0) and will let it pass.
BUTů how does the device know where to put the 1 1 1 0 code? does it have some sort of low pass filter or something ?


http://www.tpub.com/neets/book12/0217.GIF [nofollow]

audioguru

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Re: how does a PULSE code MODULATION WORKS?
« Reply #1 on: April 07, 2013, 11:53:03 AM »
A code that is 14 is made with three bursts of 38kHz (the ones) with a short pause between followed by a long pause (the zero).
Look at the datasheet of a TSOP1738 to see.

remonx6

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Re: how does a PULSE code MODULATION WORKS?
« Reply #2 on: August 02, 2013, 03:28:22 PM »
Sounds very interesting and helpful! Thanks for sharing leonheard.
PCM stands for Pulse Coded Modulation.PCM is uncompressed sound data.Each sample's amplitude is measured and stored as a number. Pulse-code modulation (PCM) is a method used to digitally represent sampled analog signals. It is the standard form of digital audio in computers, Compact Discs, digital telephony and other digital audio applications.
If u need more info watch youtube video on it
www.youtube.com/watch?v=YJmUkNTBa8s‎
If you want to calculated Pulse Coded Modulation or Impedance then use this Engineering Tools. About 38kHz Just now i check it in this online software.
http://actpcb.com/pcb-calculator

If u need more information about PCM email me. Helpful link For New engineers.
Thanks
Eng Remon