Suppose you have a remote TV in a bedroom wired to the video or satellite which is in another room. Well, if the equipment is in another room, then you have to get up, go downstairs and use the remote control. The idea behind this project, is that you take your remote control with you, aim at the IR remote control extender which is in the same room, and this will control the remote device for you. This circuit has an advantage over other similar designs in that there is nothing to adjust or set-up. Also bellwire or speaker cable can be used to remotely site the IR emitting diode, since this design uses low output impedance and will not pick up noise.
Some systems require coaxial cable which is expensive and bulky.
The wireless variety of remote control extenders need two power supplies, here one is used and being radio are inevitably EM noise polluters. A visual indication of the unit receiving an Infra Red signal is provided by LED1. This is an ordinary coloured LED, I used orange but any colour will do. You will see LED1 flash at a rate of 4 - 40Hz when a remote control button is pressed. LED0 is an Infra Red Emitter Diode, this is remotely wired in the room with the appliance to be controlled.