Purpose of Infrared signal repeater:
The infrared signal repeater is intended to extend the operating range of a standard Infra-red (IR) remote control system used with an audio or video system to around 10 meters (33 ft.). The original signal is picked up by the receiver (Fig. 1), amplified and then fed to the transmitter (Fig. 2) via a length of coaxial cable. It enables, for instance, control of an audio system located in the lounge from the dining room (where parallel speakers are fitted.
Infrared signal repeater circuit specifications:
Although in Fig. 1 the IR receive diode is a Type BPW34, good results were also obtained with a BP104. Performance of the receiver built on the PCB in Fig. 3 was found to be appreciable better than one built on a prototyping (Vero) board.
Infrared Signal Repeater Circuit Diagram:
The receiver draws a current that depends to a large extent on the digital code used by the remote control system and lies between 30 mA and 100 mA. The supply lines to T1 and T2 should be kept as short as possible.
The range of the transmitter in Fig. 2 depends to some extent on the room in which it is used, but in normal circumstances should be around 10 meters (33 ft.). The frequency of the output signals may be between 5 kHz and 200 kHz. Effective hum suppression is provided.
Care should be taken that optical feedback between the receiver and transmitter is avoided. When they are used in different rooms, that is, of course, no problem.