Need help cannibalizing a Motion sensor

Discussion in 'The Projects Forum' started by pbalien73, Dec 13, 2008.

  1. pbalien73

    Thread Starter Active Member

    Dec 13, 2008
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    I have been working on a sculpture that I would like to have a simple light turn on as people pass. I have done this before with the safety lights but not with the smaller night lights. Another problem I have is that I need this to run on a 12volt dc system and the board I have is wired for 120AC. After a few hours of blindly trying to wire this thing up with 12 volt system I get the light to work but can't seem to get the IR sensor to function.

    Questions:
    1. Can this ever work or am I going about this wrong?
    2. Is there a 12volt motion sensor out there that I can soldier inline?
    3. Can I bypass the power supply reducer and wire directly to 12volt dc?
    Thanks in advance!

    This is a picture of the board I have to work with if it helps in your answers
    [​IMG]
     
    Last edited: Dec 14, 2008
  2. beenthere

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  3. pbalien73

    Thread Starter Active Member

    Dec 13, 2008
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    Thanks, I read it and printed it. There is a bit of russian :D language in the article but it may help in the studio tomorrow. I wish they included pics as I learn by seeing. Thanks for your time.
     
  4. floomdoggle

    Senior Member

    Sep 1, 2008
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    Try using a circuit from a motion detector light commonly found at your big box store. Or, just modify the light. What you have may work, with a lot of work.
     
  5. pbalien73

    Thread Starter Active Member

    Dec 13, 2008
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    Thats what I have (from $8 nightlight) all I need is the ir to work with a 12volt dc power supply instead of the 120vac. Do I need a separate power supply for the ir sensor? How would you wire it up? Thanks for your time.
     
  6. floomdoggle

    Senior Member

    Sep 1, 2008
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    It depends on the circuit. If it runs on 12v DC you should have no problem. You could also try a rv or auto place, they use 12v as a supply voltage. Boats, too.
    But as far as a circuit goes, I'm just the handyman, can't help you there. And be ready to fry some circuits. That's the fun stuff!
    Dan
     
  7. eblc1388

    Senior Member

    Nov 28, 2008
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    In order to answer your question, one needs the datasheet of the HS0001 IC on the circuit board. I got it from a Chinese website, the data are in chinese and the IC operates at +5V supply voltage.

    The image of the circuit board you've posted indicates a capacitor voltage dropper and so one would expect somewhere on the circuit board is some regulator circuitry to give a stable +5V supply. It could be the one circled or one of those diodes(zener). Can you read what is labeled on the circled component? Partial wordings is also OK. You don't have to remove them.

    Therefore you need to provide an image of the back of this circuit board so we can "read" the copper trace and figure out what it really is. Make sure the image show clearly the traces.

    If you just connect +12V to the board without checking, you might possibly destroy it.
     
  8. pbalien73

    Thread Starter Active Member

    Dec 13, 2008
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    Sounds like you know what your doing with this stuff. Thanks very much!!! I seem to have killed the board. Good thing I bought a few (figured I might kill one in the name of art)

    [​IMG]

    Left circle part says DW1 and DW2. The black circled object on right says Q1
     
    Last edited: Dec 14, 2008
  9. eblc1388

    Senior Member

    Nov 28, 2008
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    I just bluffing most of the times. Thanks for the clear photo. It works nicely.

    After looking at the copper traces in the Xray image, I can now say with 99% certainty that two diodes DW1 and DW2 are in fact zener diodes. They are connected to the capacitive dropper bridge rectifiers via 1K resistors. One diode is dedicated for the two LEDs while the other one for the +5V regulation of the HS0001 IC.

    So it will be easy for you just to connect +12V to those positions marked in the following diagram(image). For the sake of other forum users who might found this post months later, I also upload the HS0001 datasheet here.
     
    Last edited: Dec 15, 2008
  10. pbalien73

    Thread Starter Active Member

    Dec 13, 2008
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    So it will be easy for you just to connect +12V to those positions marked in the following diagram(image). For the sake of other forum users who might found this post months later, I also upload the HS0001 datasheet here.[/QUOTE]

    Wired and soldiered as you said. I got light from the nightlight (which I really don't want) and the IR sensor didn't turn off the light after 90 sec. it continued to stay on. I really just want the ir motion sensor to work with a 12volt light source. Cand I make my own board with the parts? How should I proceed? I don't want to burn this one out. Thanks for your time and trouble.
     
  11. eblc1388

    Senior Member

    Nov 28, 2008
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    Don't give up just yet.

    Have you replaced the whole circuit board back into their original casing when you did the test? There are light barrier and IR filter covering the the IR sensor which most likely is mounted on the casing. Without this filter, the whole circuit will not work. You have to reassemble the whole thing and let the two extra battery connecting wires out in a gap of the casing somewhere.

    Yes. I know what you wanted. But that's the second step down the line. What we need to do first is to make the night light works as it should on DC 12V instead of 120V AC.

    When you have achieved that, then we can use it to drive a 12V light.

    The final step is to adjust the ON timing of the 12V light upon detecting personal movement.

    Of cause you can. But it will not be any simpler that this one. Just looks at the diagram I posted in my first reply post. That is the schematic drawing you'll need to connect other parts up to use this IR detector.

    Unless you can buy a ready made one for your special purposes, I don't think there is any easy way out.

    There are alternative circuit designs that don't use IR but use instead a single LDR which detect slight change in ambient light level as people walk pass and it can also suit your requirement.
     
  12. pbalien73

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    Dec 13, 2008
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    Ok, thats great. I'll put the light back together and see if it works.
     
  13. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    Looks like the sensor is a "flake thermistor tied to a fet "?? It detects body heat or rather contrasts in heat received. Might be able to just use sensor,comparator and of course a 555. With power applied it would be interesting to monitor voltage at junction of 2.2k&22k to gnd.
     
  14. pbalien73

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    Dec 13, 2008
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    Sounds like what I want to do. Can you give me drawing of how wire (in english:))
     
  15. Bernard

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    My suggestion is to stick with present ckt. board with eblc1388's help,seems you are close. A new ckt. has its own growing pains and without a sensor in hand to "play " with could lead to many false starts. Murata Mfg, IRA-E 712ST3, Newark part # 97K1949 @ 45.24 looks much like you have. PIR has multiple meanings: Pyroelectric Infra Red,Passive Infra Red . Google lists many motion detectors,most or all would need some interfacing.
     
  16. pbalien73

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    Dec 13, 2008
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  17. eblc1388

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    I'm glad it finally work.

    You need to tell us what type of 12V lamp(s) you are trying to use, like current or wattage if you know about it. Or attach a photo showing the 12V light.

    Depending on the current, you might be able to drive them directly using the transistor inside the Night light unit.
     
  18. Bernard

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    Just found interesting item from Goldmine Electronics , PT # G4567 $4.95.PIR operating on 9V battery with instructions to add relay[or lamp ]. Sale ends 1-1 09. For backup just incase. I have to have one.
     
  19. Bernard

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    The Dec. 2008 issue of 'Nuts and Volts " has an interesting article, Build A Dog Detector, covering several motion detection schemes.
     
  20. Bernard

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    I now have one & it catches me every time I entor " library ".
     
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