Thursday, March 27, 2008

IR Remote Control Extender

I needed to run an IR signal between rooms and didn't want to cough up the $50 for a commercial extender.

Most parts are scavenged or what I had laying around.

The basic premise is to use a IR decoder module that strips out the 38-40kHz carrier and turns it into a logic signal, then let that gate a 555 timer running astable at 40kHz.

The IR module I had runs active low though, so I had to setup a transistor inverter to bring it to active high. The inverter out runs a transistor hooked up to a red LED to indicate when signal is being received. It also runs to pin4 of the 555 (reset pin) which when low will drive the 555 output low regardless of state. Some long wire running into the other room is terminated by an IR LED. Voila! The circuit runs of a wall-wart and contains a 5 volt regulator (LM7805) and reverse-polarity protection diode.

Works, can't complain :)

No comments: