IR xmtr problem

Discussion in 'General Electronics Chat' started by tracecom, May 4, 2011.

  1. tracecom

    Thread Starter AAC Fanatic!

    Apr 16, 2010
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    I have a set of venetian blinds in a window that is 18 feet from the floor. I installed blinds that are motorized and allow the blinds to be tilted up and down when triggered by an IR remote. I tested the blinds thoroughly before installing them and they worked as designed: push the button on the remote and the blinds begin tilting up or down; push the button a second time and the blinds stop; push the button a third time and the blinds begin moving in the opposite direction from the first push.

    Now the blinds have stopped responding to the remote. The motor in the blinds is powered by a set of AA NiMH batteries which have seen very little use, but I will check these batteries as a last resort. The remote is powered by three AA alkaline batteries, which I have just replaced.

    When I press the button on the remote, I can see the LED glow a dim red with the naked eye. When viewed through a digital camera, the LED glows white, but is not very bright on the camera's LCD screen...just a small white circle. I am suspicious that the problem is with the remote.

    Attached is a picture of the PCB in the remote; the IC is an NE555. I would appreciate suggestions as to a trouble shooting procedure or other alternatives. I don't have any technical documentation on the remote and don't even know the frequency of the IR LED. Obviously, I can try to get a replacement remote, but if that fails, what other options are there? Would it be possible to build a replacement? Are the signalling sequences standardized on remotes like this? Does anyone here have any inside scoop?

    Thanks.

    ETA: Just found the following link by googling the numbers on the PCB. http://www.hifi-remote.com/forums/viewtopic.php?p=58422&sid=e067d4c4a4c9d1f931cd95e2222acef1
     
    Last edited: May 4, 2011
  2. tracecom

    Thread Starter AAC Fanatic!

    Apr 16, 2010
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    OK, the remote was made by Somfy. I talked to tech support there and was told the remote was discontinued (no surprise there.) I asked for a schematic and didn't get one, but was sent the attached file, which I don't understand but will study.


    ETA: I suppose my remote is a single channel since there is only one button. In addition (from the file), the IR wavelength is 950nM, the frequency is 38kHz, and the protocol is Philips RECS80. Now, to understand the datastream and how to recreate it.
     
    Last edited: May 4, 2011
  3. GetDeviceInfo

    Senior Member

    Jun 7, 2009
    1,571
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    wife sells the Hunter Douglas brand. Do you have a manual override button on the reciever in the headrail? I'd be checking the batteries up there first.
     
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