Infra Red Extender
Mark 4A for 36KHz

Circuit :  Steve Jackson, UK
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An Infra Red wired Repeater circuit to control appliances from a remote location.
Infra Red extender mark 4a Parts List:
R1: 1k Resistor (1)
R2: 3.3k Resistor (1)
R3: 10k Resistor (1)
R4: 15k Resistor (1)
R5: 2k2 Resistor (1)
R6: 1k Resistor (1)
R7: 1k Resistor (1) 0.5 Watt
PR1: 4.7k Preset (1)
C1,C4: 47u Elect(2)
C2: 1n Polyester 5% or better (1)
C3: 22n Ceramic(1)
Z1: 5V1 Zener (1)
Q1: BC107 (1)
Q2: BC108 (1)
D1: 1N4001 (1)
IC1 : TSOP1736
IC2: 555 or 7555 (1)
LED1 5mm RED (1)
LED2,3 IR diode TIL38 or similar (2)

This is a modified Mk 4 Infra Red Repeater by Steve Jackson. The IR receiver, IC1 is a TSOP1736 removed from an old defunct Sky Digital receiver. A few minor changes have also been made including a series diode D1, on the 12V to safeguard against incorrect supply polarity.

The power supply was taken from a Philips LCD monitor which has a 12V DC output, although any 12V DC supply should work ok, current required 100mA. The IR emitter chain was also salvaged from an old audio video sender. This IR chain has three emitters and they are attached directly to the front of the device to be controlled. As a result I was able to increase the current limit resistor for this. I had a small plastic case in my spares box and it all went together very nicely. See the attached photos of the veroboard layout and various views of the finished unit below.

Prototype Mk 4A
Click Images to Zoom

Hardware Compatibility List:
If you make the Mark 4A circuit please let me know if it works and the make and model of your remote control, or the device you are controlling e.g. CD player. I will add this to the hardware compatibility list below:-

Philips DVP3005 DVD player
Logic3 LG176 Super VGA Box with TV Tuner
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