circuit problem??

[cool]

I have a circuit about a IR modulation. Any around 40kHz IR signals will will be detected and decoded. However, I want to detect 20kHz IR signal instead of 40kHz~ :cry:
How can I change the circuit?? which components' values have to change??
THANKS~~ :lol:

The circuit in https://www.electro-tech-online.com/custompdfs/2004/02/k58.pdf

 

[Nigel Goodwin]

I have a circuit about a IR modulation. Any around 40kHz IR signals will will be detected and decoded. However, I want to detect 20kHz IR signal instead of 40kHz~ :cry:
How can I change the circuit?? which components' values have to change??
THANKS~~ :lol:

The circuit in https://www.electro-tech-online.com/custompdfs/2004/02/k58-1.pdf

You need to change the IR receiver IC, I don't know if you can get one for 20KHz or not - but why would you want to change it?.

 

[cool]

Oh, actually, I don't want my IR receiver is affected by some common TV remote control easily~ since most of the IR signals used in the market is around 40kHz~ :?
So I want to change the circuit no matter it is 20kHz or not~ I just want my IR receiver can only detect my transmitted signal. :wink:

then what can i do??? :?: :?:

 

[Nigel Goodwin]

Oh, actually, I don't want my IR receiver is affected by some common TV remote control easily~ since most of the IR signals used in the market is around 40kHz~ :?
So I want to change the circuit no matter it is 20kHz or not~ I just want my IR receiver can only detect my transmitted signal. :wink:

then what can i do??? :?: :?:

You do like normal remotes do, you transmit a code specific to your receiver - you can do this with PIC's, see my IR remote tutorial at http://www.winpicprog.co.uk. Or Holtek make IC's specifically for that purpose, have a look at http://www.holtek.com.