Film-Tech Forum ARCHIVE: DTS - What LED bulb is used?

This is topic DTS - What LED bulb is used? in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Tissa DeSilva (Member # 4389) on 01-12-2008, 11:46 AM:

Hi
Can anyone tell me what is the size , voltage and power of the Red Led bulb used in DTS Readers. and where we can buy them?
Thank you in advance.

[ 01-15-2008, 01:39 PM: Message edited by: Aaron Sisemore ]

Posted by Jim Cassedy (Member # 4115) on 01-14-2008, 11:15 AM:

I have 0% practical experience working with DTS systems but I do have a couple of equipment manuals here and I can't find any reference to the LED other than that the proper operating voltage for it is 4V.
I can't find any other specs or even a replacement part number for it in the manuals I have. Your best bet bet might be to contact DTS directly for the info you seek.

Posted by Bruce Hansen (Member # 281) on 01-14-2008, 05:38 PM:

DO NOT EVER put 4V across a red LED. It will FRY. The 4V is measured on the READ side of the reader, and is adjusted by adjusting the gain of the reader side, NOT the LED voltage. The LED is fed through a fixed resistor, and is not adjustable.

Posted by Tissa DeSilva (Member # 4389) on 01-14-2008, 08:59 PM:

Do you know what Red led buld it use? I remember its 2.5 MM led. But I want to know where to buy and what are power or bright requirments.

Posted by Mark Gulbrandsen (Member # 72) on 01-15-2008, 12:09 AM:

Contact Gord McLeod...I know he has the LED's and he also does rebuilds of the TCR. It is no easy task to replace it....

Mark

Posted by James Westbrook (Member # 3690) on 01-15-2008, 02:58 PM:

Wouldn't it be easier to do an repair/exchange with DTS on the readers? Will DTS not do this with the Canadian theatres like they do with us here in the States?

Posted by Eric Robinson (Member # 2966) on 01-17-2008, 01:34 AM:

quote: Bruce Hansen
The 4V is measured on the READ side of the reader, and is adjusted by adjusting the gain of the reader side, NOT the LED voltage.

Interesting... here's a hypothetical question. Assuming every aspect of a reader is in perfect working order and calibration other than the LED and reader. Would the most common case for failure be attributed to the LED fading or the reader elements losing their sensitivity? What is the reader element?

Posted by System Notices (Member # 2357) on 02-16-2009, 10:31 PM:

It has been 396 days since the last post.

Posted by Eric Webb (Member # 2772) on 02-16-2009, 10:31 PM:

Does anyone know where find the led voltage fuse on the D422 board as stated in the DTS6-D system testing and troubleshooting guide in the manuals section of Film-tech? Because recently when I power on the DTS6 unit the reader led does not light but the player boots up fine. Any ideas?

Posted by Mark Gulbrandsen (Member # 72) on 02-16-2009, 10:58 PM:

Try a different reader first. I don't think there is a fuse in the 6-D, there is one on the 6 though. Hopefully Mike Smith is still out there.... he could tell you for sure...

Mark

Posted by Monte L Fullmer (Member # 2797) on 02-16-2009, 11:16 PM:

Had a DTS-6 do the same thing: boots up, green light on reader stayed on for a few seconds then drop completely.

Had to send the unit and reader in to the place in NY and they overhauled the unit with new SCSI cards, DVD Rom drives and repair the timecode reader section of that one particular card. They also replaced the reader when I got the player back.

-Monte

Posted by John Hawkinson (Member # 1135) on 02-17-2009, 01:59 AM:

Measure between pins 5 and 6 on the DB9 cable that plugs into the TCR. If you have 5 VDC, then your supply voltage is good.

--jhawk

Posted by Mike B. Smith (Member # 2829) on 02-17-2009, 01:34 PM:

There is no fuse in the Timecode reader head. Power from the head comes from the player, the DTS-6 has a fuse for the 5V power located on the 422 board,(the one with the status LED's). Fuses are located near the top of the board by the rear connector. On early units this fuse was soldered in and looks like a small reisitor, later units had the plug in type fuse, it was changed again to the resetable type fuses in 6D's. Prior to blaming failure of the LED verify you are getting voltage to the head. On the 9 pin TC cable pin 6 should be ground and pin 5 is the +5V Verify you are getting power to the head

Posted by Bruce Hansen (Member # 281) on 02-17-2009, 07:48 PM:

Be careful, DO NOT short the 5VDC to ground (or anywhere else). To see if the LED (or wiring to it) is bad, check the voltage across it (where the wires connect to the board). If the LED is bad, it will not be drawing any current, and there will not be a voltage drop across it's current limiting resistor, so you will see the 5 volt supply voltage across it. If there is no voltage, but there is 5 volts being supplied to the reader, then check the current limiting resistor. It is R15 a 360 ohm resistor. A good red LED will have about 2 volts across it. BTW, an LED is a current opperated device, not voltage opperated.