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B&t Tracer unit, xenon flash not working.

Discussion in 'Troubleshooting and Repair' started by Andyuk, Dec 7, 2015.

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  1. Andyuk

    Andyuk

    28
    0
    Dec 7, 2015
    Hello,
    This is my first post here.
    This unit is designed to light up glow in the dark balls as they pass through a tube. either side of the tube is an LED as the ball breaks the LED light, it fires the xenon compact flash.
    My knowledge of electronics is limited so any help would be great.
    The voltage source is 4 x 1.5 volts batteries. Once the power is on, One led lights up red and shines through a clear tube to the receiving LED. when the beam isn't broken the receiver LED reads 0.1 volts, when you break the light it reads 0.7 volts.
    I'm getting 370 volts across the flash tube but I cannot get the high trigger voltage to fire. The trigger voltage comes from T2.
    I have changed the flash tube but it still doesn't fire. I have attached a couple of images.
    Like I say any help would be much appreciated.
     

    Attached Files:

  2. shrtrnd

    shrtrnd

    3,808
    511
    Jan 15, 2010
    Can't help with what I know so far.
    Have you got a model number of this device, maybe a schematic.
    You're generating High Voltage from 4 each 1.5V batteries, so I suppose anything could have taken a hit on that circuit board.
    I'll also mention, that it's not all that unusual to just burn-out one of those lamps themselves.
     
  3. Martaine2005

    Martaine2005

    3,323
    910
    May 12, 2015
    T2 looks like the wrap has come away and the black plastic has bubbled!
    I think this is a job for "super Edd"

    Martin
     
  4. GPG

    GPG

    452
    66
    Sep 18, 2015
    You have to turn on the SCR labelled 'TH'
     
  5. Andyuk

    Andyuk

    28
    0
    Dec 7, 2015
    The middle pin of the SCR reads around 38v, when you break the light beam it drops to around 0.7v.
    The left pin gives 0v, and when you break the light beam you get 0.7v
    The right pin doesn't change at all, it gives 0v constantly.

    The SCR is labelled K100-6 1408
     
  6. Andyuk

    Andyuk

    28
    0
    Dec 7, 2015
    I agree the trigger transformer does look like its overheated. across the primary I get 0.7 ohms, from primary to secondary I get 154.5ohms across one leg and across the other 155.1 ohms.
     
  7. GPG

    GPG

    452
    66
    Sep 18, 2015
    Would expect more Typical cct:
    http://www.bristolwatch.com/ele/
    Check trigger capacitor/resistor
     
  8. 73's de Edd

    73's de Edd

    3,070
    1,299
    Aug 21, 2015
    .


    Sir Andy . . . .United Kingdom ?




    Can anyone, fo' sho', confirm that S100-6 IS a SCR ?, and not actually being a flat pack HV Mosfet. . . . . . now, full size 106 SCR's I has KNOWED abouts . . . . for quad / quinti decades.

    Why for the GEEEE-I-ANT Poly caps that are being strung outside of the circuitry . . . if subbed in for the "charge" capacitor which fires the semiconductor, asurredly they would have too
    great of a time constant, to charge up quickly enough.
    One usually finds a .01---.05 @ 1kv cap being used for this applicaton.

    I just made alterations, to make a quick tack in illustration of the typical trigger transformer, which is usually arranged as an autotransformer, I may have the GREEN and BLUE wires reversed
    from their proper connections.
    Those connections apparrently have to pass across the board, to reach to their SCR ? Mosfet ?

    Referencing to the addditional HOW-TO schema, generously provided by our Most Honorable and Esteemed colleage . . . . GPG . . . . .

    Take digital voltmeter ( versus a common analog VOM, which would LOAD down) in hand and check to see if the R9 marked resistor might have your 38V on one of its ends and have the 370 V
    supply on its other end, and ceramic cap C2 might just be the one that charges up from R9 and fires the primary of the trigger transformer.
    Then check R9's actual resistance, as usually higher than 40 V is being used to "ping" a trigger transformer.
    If so, C2 may be leaky if under voltage spec'd.
    An ole po' boy test for your HV output of the trigger transformer at the RED line mark ups would be to use one of the neon lamp "flicker" test lamps to ground, (or a NE-2 family of lamp, should
    you have one ) while you fire up and ping the unit.
    It should flash quite bright.

    That Flickee-flickee . . . . . . . . . .its-a-look-a-like-a-dis . . . . . . . .
    [​IMG]

    I marked in the YELLOW and RED arrowed LED and phototransistor, being used as a photo-interruptor pair, but they seem to be operarting all right . . . . as per your given readings.

    Le Picture . . . . . . . .

    [​IMG]
    You do know that this is the right time of the year that you can drag leather or rubber soled shoes across the carpet and get a good solid spark to ground.
    Meaning . . . . . . that if you just have the floating trigger wire ring, wound around the one end of the flash tube, . . . . . being disconnected from trigger transformer circitry.
    Grounding the battery negative connector, and placing a carpet CHARGED fingertip to the trigger wire ring should fire the flash tube if charged up.

    O r r r r r r r r r . . . . . if you have a one Amellican dollah / Chinese piezo "firestarter" and bare a 1/4 inch end of hook up wire and place a slightly larger piece of spaghetti tubing around it, it is possible
    to route down to make the new wire connect to the wire that normally arcs to the shell to make a spark. The spaghetti insulates the pair so that the HIGH voltage is conserved by virtue of no sparkover
    then being possible. Then the other end of the hook up wire provides that excitation HV to the flash tube trigger ring, if your left hands finger "grounds" to the battery negative .
    Any resultant tingle is being no worse that a typical carpet static shock.

    [​IMG]
    Query:

    Is the blue HV storage electrolytic rated at 400VDC and ????? capacitance ?

    What is the quasi- clear plastic ring (shower curtain ring ) under the HV side of the flash tube and the HV cap . . . . .being just a precautionary item that you used to insulate and hold up those components ?


    Thasssit . . . . .


    73's de Edd


    .
     
  9. 73's de Edd

    73's de Edd

    3,070
    1,299
    Aug 21, 2015
    .



    Tnx . . . . . .
    and praise be given to GPG.

    For the ALL important required MCK prefix / idenifier
    When dealing with "new kid on the block " manufacturers.



    73's de Edd

    .
     
  10. Andyuk

    Andyuk

    28
    0
    Dec 7, 2015
    Edd

    Thanks for taking the time to put that together. I've been on the verge of giving up, but now, I have a little more hope.
    I used a piezo and managed to fire the flash. The flash that's in the picture is a new one I purchased. here is a picture showing the old flash tube. The rubber ring is used to hold the reflector against the tube. The reflector has the trigger wire soldered on.
    The blue cap is rated at 10v 470uF and is connected in series to another under the board which is a 10v 220uF, I guess its done this way due to space.

    R9 has 38v on the bottom which drops to 0v when triggered. 370v on the top side. R9 measures .995 when removed
    C2 has 38v on the bottom which drops to 0v when triggered, Top side reads 0v but when triggered drops to -20v then to +20v there abouts.

    upload_2015-12-10_9-9-57.png

    I ordered this on ebay a couple of days ago, it should be here today. But I don't think it will be supplied enough volts.
    http://www.ebay.co.uk/itm/4kV-TRIGG...467030?hash=item2ee8d064d6:g:qM4AAOSwys5WWJCp

    I don't have anyway of checking C2. If that was defective would it cause a lower voltage to T2.

    Thanks again
     
  11. GPG

    GPG

    452
    66
    Sep 18, 2015
    .995 what? What are its markings. Anything written on the trigger capacitor?
     
  12. Andyuk

    Andyuk

    28
    0
    Dec 7, 2015
    It measures .995 MΩ. The resistor is labelled
    [​IMG]
    There are no markings on the capacitor.

    Thanks
     
  13. Andyuk

    Andyuk

    28
    0
    Dec 7, 2015
    wow that's a big picture.
     
  14. GPG

    GPG

    452
    66
    Sep 18, 2015
    OK so the resistor checks out at ~1Meg. that leaves the capacitor and scr as possible leakage sources. With the cap disconnected measure the voltage on SCR
     
  15. Andyuk

    Andyuk

    28
    0
    Dec 7, 2015
    The voltage at the SCR doesn't change with the cap removed.
     
  16. GPG

    GPG

    452
    66
    Sep 18, 2015
    Can you disconnect the SCR? Board leakage is a lesser possibility (just to confirm) but you may have a leaky SCR. Edit: check the value of the cap if your meter is able
     
  17. Andyuk

    Andyuk

    28
    0
    Dec 7, 2015
    Unfortunately I don't have a meter that can check the cap. But with the SCR removed I get the 300 plus volts on the middle pad.
     
  18. GPG

    GPG

    452
    66
    Sep 18, 2015
    So finding a sensitive gate SCR replacement is your mission should you choose to accept it.
     
  19. Andyuk

    Andyuk

    28
    0
    Dec 7, 2015
    I'm already on it.
    I've just had the biggest shock so far, wow got to turn things of before soldering.
     
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