Please recommend a proximity sensor, some lighting and video

Discussion in 'Bob & Don's Electronics Forum' started by leejosepho, Nov 30, 2013.

  1. DonL

    DonL Jack of all trades Master of one

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    After looking at the DVR-4 manual the DVR looks like it has 75 ohm terminators built in on its 4 Inputs.


    Where are you looking that the video looks bad ? On Output #1 of the DVR-4 ? Are you terminating into a 75 ohm monitor Input ? The 2 outputs are made to drive (1) 75 ohm load.
     
    Last edited: Dec 20, 2013
  2. leejosepho

    leejosepho DIY scratch-pad engineer

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    disabled-retired industrial fabricator
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    Here are the docs for my DVR: http://www.swann.com/downloads/drivers/dvr4net/

    The DVR has two video outputs, and neither is labelled as "1" or "2". In the past, I have had a cable connected at each output even though I have only been using one or the other...and I have just now done a test by connecting both DVR outputs to the dual-input monitor, and that definitely improved the DVR output (less washout). So, I am assuming the 75-ohm terminator I just ordered for one of the DVR outputs will do the same. Overall, however, it still seems the DVR and cameras are competing for control of adjustments related to ambient light during low light. For example, and with everything connected, I typically have to do a factory reset of the DVR to get a good picture, but then passing my hand (about three feet away) in front of a camera in low light will again put the DVR output into a washed-out state even though the same does *not* happen when the camera is connected directly to the monitor.
     
    Last edited: Dec 20, 2013
  3. DonL

    DonL Jack of all trades Master of one

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    Are you using the 12 Volt DC adapter that is made for the DVR ? I think you bought it used ?

    Are your cameras powered separately ?

    If you can see a difference with both output connections connected, You may be onto something.

    But why you should have to do a factory reset , tells me that you have other problems also.

    You might try changing the DVR Sensitivity settings to Low.

    If the Video signal is distorted the DVR may not like it. Does it do the same on all cameras ?

    You could also be looking at a freeze frame, and the IR is washing out the video.


    Have fun.
     
    Last edited: Dec 20, 2013
  4. leejosepho

    leejosepho DIY scratch-pad engineer

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    disabled-retired industrial fabricator
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    200 miles south of Little Rock
    Yes, and yesterday I played around a bit to see whether cable length made any difference. Overall, it seems the 60' cables are fine, but I do wonder whether the cameras need a while to warm up or whatever. Yesterday I first had some raster lines that eventually went away after I had swapped cameras and cables around a bit, then that problem never came back even after I had put things back as they had been.

    Since the DVR has no power button, I have experimented a bit with whether to power the cameras before or after powering the DVR and/or before or after even connecting the cameras to the DVR. Overall, it seems a factory reset after everything is connected and powered is how I get the best results.

    Switching cables and cameras has not made any difference even though the raster lines eventually went away while I was trying all of that. My IR reception is a bit grainy in the dark, and I had to lower the motion sensitivity in the dark to keep that from going off even when there was no motion to detect.

    Yes, I bought it used, and what is that adapter? Do I need to be using some kind of Y to put both outputs into one?
     
  5. DonL

    DonL Jack of all trades Master of one

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    Sorry, I screwed up on my post.

    That should have been 12 Volt power supply adapter.

    The one that supplies power to the DVR.

    Next time it gets hosed you should try to kill power to the cameras and see if that helps.


    The DVR hard drive can crash if the DVR is not shut down properly. If it is writing data its outcome is not good.


    The cameras should not need to warm up, but the power supplies that come with them are normally underrated. Even more so if the camera has IR LEDs on a long cable run.


    Have Fun.
     
  6. leejosepho

    leejosepho DIY scratch-pad engineer

    Joined:
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    Occupation:
    disabled-retired industrial fabricator
    Location:
    200 miles south of Little Rock
    The AC adapter appears to be a decent one with a 12VDC/4.58A output, so I doubt that is the issue. Also, I have just used a new Swann RedAlert-DVR in place of the DVR4-Net, and the video coming through that little unit is fine all the way around. So, either there must be something wrong with the DVR4-Net or else it just does not know how to get along with newer cameras and whatever adjustments they can make based upon ambient lighting. The RedAlert-DVR can only record from one camera at a time even though it can accept up to four, and it can only handle a 2GB SD card. However, it seems to work as it should and it just did a good job of catching me wandering around in my carport! Right now I have the camera pointed out at the street, but the picture is too small and the distance too great to be certain as to which of my neighbors just drove past.

    If either of you want to play around with the DVR4-Net to see about possibly getting some good video to come out of it, just let me know and I will gladly send it to you. I only paid $35.00 for it, but I still hate to just throw it away.
     
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