Infra-Red Extender - Problems - Electronic Circuits Projects Diagrams Free

elMickotanko · 17th April 2004, 05:30 PM

Hello, Im in dire need of some help.
Im starting out in electronics, Im fine with the theory which I learn at college but theres not nearly enough practical work. Ive tried various projects on my own which never seem to work. Its very frustrating. One such project is this infra-red extender , a pic of the circuit is attached.
I built this on veroboard with the IR emitter on a seperate small bit of veroboard, connected by wire. I also used the daylight filtered version of the Photodiode.
When I operate a remote control pointing at it, LED1 (indicator) flashes like its supposed to, but LED0 (when pointed at the television) doesnt pass on the signal.

Im thinking: LED1 filckering suggests that the circuit is operating correctly but the infra-red pulse code is being distorted?
Ive tried the CD player and the Cable TV box also

Can any1 suggest how i could fix it? I can get most common parts from college. Or even modify it to do something else hobby-like (you know, something i can impress people with)? as this is the closest ive got to getting a circuit to work Im determined to get it working.
Any help would be greatly appreciated

pike · 18th April 2004, 01:55 PM

I think the 2.2k resistor behind the IR led is too high. You can use a lower value for this resistor as the IR led is only turned on for a short amount of time.

If the red LED flashes that means that you are getting a signal, but like you said it might be distorted. You could try using different IC for the amplification.

carlosthejackle2001 · 18th April 2004, 04:45 PM

Look into the HOLTEK chips HT12D and HT12E, you will easilly be able to create an infra-red transmitter and receiver... Check out their data sheets they come with recommended circuits to build.

Need any other help you can email me at rampant_tup@yahoo.co.uk

I am using these chips for my infra-red project at college and they have made things very simple

Carl

elMickotanko · 21st April 2004, 09:31 AM

Those chips are a bit over my head at the minute. But i'll try a lower resistor and a different chip. My construction skills are very poor also, maybe this has something to do with it?
Thanks for your help.

pike · 21st April 2004, 03:38 PM

don't go past 50 ohms for the resistor below IR1

I found it so hard to determine if an IR led was burntout or not (you can't see infrared)

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18th April 2004, 01:55 PM	(permalink)
pike	I think the 2.2k resistor behind the IR led is too high. You can use a lower value for this resistor as the IR led is only turned on for a short amount of time. If the red LED flashes that means that you are getting a signal, but like you said it might be distorted. You could try using different IC for the amplification. __________________ www.winpicprog.co.uk - Great PIC language tutorials.

18th April 2004, 04:45 PM	(permalink)
carlosthejackle2001	Look into the HOLTEK chips HT12D and HT12E, you will easilly be able to create an infra-red transmitter and receiver... Check out their data sheets they come with recommended circuits to build. Need any other help you can email me at rampant_tup@yahoo.co.uk I am using these chips for my infra-red project at college and they have made things very simple Carl

21st April 2004, 09:31 AM	(permalink)
elMickotanko	Those chips are a bit over my head at the minute. But i'll try a lower resistor and a different chip. My construction skills are very poor also, maybe this has something to do with it? Thanks for your help. __________________ My Space

21st April 2004, 03:38 PM	(permalink)
pike	don't go past 50 ohms for the resistor below IR1 I found it so hard to determine if an IR led was burntout or not (you can't see infrared) __________________ www.winpicprog.co.uk - Great PIC language tutorials.