The Cyber-Spy.Com Usenet Archive Feeds Directly
From The Open And Publicly Available Newsgroup
This Group And Thousands Of Others Are Available
On Most IS NNTP News Servers On Port 119.
Cyber-Spy.Com Is NOT Responsible For Any Topic,
Opinions Or Content Posted To This Or Any Other
Newsgroup. This Web Archive Of The Newsgroup And
Posts Are For Informational Purposes Only.
From: "Michael A. Terrell"
Subject: Re: Common IR remote control frequencies
Date: Fri, 25 Oct 2002 00:57:44 -0400
Organization: Do I have to? Well, Ok. If you insist!
X-Mailer: Mozilla 4.61 [en]C-CCK-MCD (Win95; U)
> Michael A. Terrell wrote:
> > anc wrote:
> >> I believe that a common frequency for the carrier used in IR controls is
> >> 38KHz and that certain satellite receivers use 115KHz for the carrier. The
> >> TSOP 1738 is a 3pin IR receiver that will decode a 38kHz modulated carrier.
> >> What would happpen if an IR control using 115KHz was aimed at this device.
> >> Would it strip off the carrier leaving the control
> >> pulses or would filtering in the TSOP1738 prevent any output?
> There would be no output at all.
> >> I am looking to design a universal IR repeater. The problem is getting a
> >> receiver to accept all carrier frequencies.
> > Why demodulate and remodulate them? Use a detector to see if it is
> > modulated above a set frequency and use the output to control
> > transmission. This way, your signal already has the right modulation
> > and timing.
> The problem is that enviromental noise may be high.
> Fluorescants spew out lots of noise in the same broad range as remotes.
> Simple repeaters may reduce the signal-noise greatly.
> Some simple approach like a bandpass from the IR reciever, from 5Khz-500Khz
> and something to amplify and AGC it down to the range of the LED might
> be most compatible.
> Is this for a one-off, or production?
> http://inquisitor.i.am/ | mailto:email@example.com | Ian Stirling.
> "An enemy will usually have three courses open to him. Of these he will
> select the fourth." -- Helmuth von Moltke
Would you take a little more care when you snip previous messages?
Michael A. Terrell
Go Back To The Cyber-Spy.Com
Usenet Web Archive Index Of
The sci.electronics.design Newsgroup