Maximum carrier frequency for infrared tx/rx

Hi all,

May I know what is the max carrier frequency for the infrared? I know that some 3-pin IR receiver demodulator IC takes the carrier frequency of 38 kHz. I've seen some receiver with 2 pins (LED alike), can they detect the frequency that is higher than 38 kHz?

I'm asking this because I would like to make a IR transmitter for the air cond, by reading and saving the IR emitted from the original remote control. So I can turn on without the original remote control.

The reason is, of course not for jamming. In my office, the remote controls are on the admin's desk. Everyone can take them. But some 'intelligent species' take the controller without returning. Recently I have to start working at 6 am. There's nobody else in the office and it's hot, and the remote control is not returned!! I don't mind to turn it off if others feel cold/sick during the office hour, but when I'm alone at least allow me to have a confortable working place.

Apart from that, since I started working full time after my college, I've never been doing any project over the pass one year (since June 2008). So I want to take this opportunity to continue what I'm actually interested in .

Thanks

Almost all remotes use around 38KHz, you need to read the original remote with something like a PICKit2 in logic analyser mode fed from an IR receiver IC - then duplicate that using a PIC or similar, but generating a series of 38KHz pulses to create the LOW parts of the received pulses.

Or you could go to a shop and buy a simple learning remote, and point the old remote at it.