Infrared Emitters in Tag Heuer TL 2-35

You will probably find it very difficult to repair this. An option could be to find another old TAG cell, possibly a 2-11 or 2-31, that is not working. Often these reflector type cells no longer receive but still emit fine and could be a replacement for your failed unit. If you are looking to replace, the ALGE PR1a is an excellent unit. Since it has come out I have purchased many of them and love the fact that they can be used as emitter, reciever or reflector cell.

Thank you for the reply, i don't think i can find another Tag cell in my country, i had last year a receiver that failed, i just replaced the optocoupler on the board (a black chip with 6 legs, very cheap) and it works perfect.
I had a chance to use ALGE cells, they are a bit biger, heave a nice shield, easier to install and align, maybe the nex generation of cells to be bought will be Alge (i see they are easier to repair).
Ill come back when i find a solution to this.

From the datasheet it doesn't look like that part is anything special. I would try a regular 880nm led, preferably flat top. Just make sure you get the anode/cathode direction correct.

Hi, you are wright, but i have to wait a week before crossing that bridge (at first i'll do a mok'up comparing the position to the original one)

I have ordered this part http://www.adelaida.ro/led-emi...u-sfh4811-osram.html but it is not in stock, probably it's in the UK or something. Not quite like the originall but 95% there (the original i think is no longer in production by Siemens, who seem to sold the production line to Osram, who in turn have on the internet pg. a note anouncing the SFH 481 is out o production (streamlined production or something) and replaced by SFH 480 2/3 and SFH 482, couldn't source them either so i went whith the closest i could find).

By the time i'm done i think i'll get a phd in IR EMITTERS !!!

If this doesn't work, back to the drawing table (part is like 10$ tops).

You could try the Fairchild QED223, which digikey has 16000 in stock of, $0.72 single quantity.

To tell you the truth, i have bought a similar looking diode from an electronic store (seems to be from a remote control), not sure about the wave length of 880 Nm, or other specs but will give it a try this week.

The Fairchild unit is a bit larger in diameter, .25mm over and some other specs are a bit off, overall i would try it. Ill just have to go to an oversize bore on the circuit board.

First -have you checked proper function of cell electronics with the osciloscope? It`s a kind of generator, with frequency of several tens of kilohertz.
The wavelengths schould be the same in transmiter and receiver. But for most IR receivers for 880nm, if the transmitter have 960nm(most common in remote controls) -the sensitivity will be reduced only to 90%. So it`s not bad.
Almost the same element, than oryginal to buy in Romania is there: http://www.tme.eu/ro/details/v.../diode-ir/excelitas/

If you have some more questions, please wright me. I am a producer of timing equipment, including fotocells and I have some experience :-)

Jarek
Gro-Timing.com

Hello, i had the unit checked by someone with more knolege on electronics, but i don't think he used an osciloscope, he used a multimeter and compared the values with a known goog working Tag cell (the trick worked last year on a receiver).
I have looked at all the IR emitters online, including the one sugested by Jerry G (thank you for your time and input), the dimensions of the diode don't seem to match up, neither the electric properties (in it's description the intended use is for close distances).
If the one i ordered doesn't work i'll try tme.eu, this Tag cell has been in storage for a couple of years, last year I came across it and decidet to try to fix it.

Hello,
I finally received the IR emitter after 10 days (initialy it should of been 7 days), it fits perfect but i had to replace again the adiecent tranzistor (the original model was 680 and the replacement part i got the first time was a model 680 A).
From what i can tell it run's just like the original, i had a go with a plastic IR emitter, it seemed to run fine but it would get hot very fast and the external diameter was bigger (but i don't remember if i did the test with the 680 A tranzistor (it was allowing for a higher voltage at the IR emitter) or with the good 680 tranzistor).

So after a month of troubleshooting and part sourcing i got it running, next post hopefully i'll tell you how i managed to repair 5 CP 501 and 2 CP 502 (i know they are antiques but better to trash these units in very dusty enviroments rather than the CP 520 or the CP 540