Solenoid Charge-up driver schematics

Discussion in 'General Electronics Chat' started by JK-FlipFlop, Mar 26, 2011.

  1. JK-FlipFlop

    Thread Starter Member

    Jul 5, 2010
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    Hi,
    I bought (for my Robot project) powerful solenoid driver, that charge up to 110v and discharge when the control pin goes high. The effect is very strong, The solenoid current is very high (about 15 amp) and this driver taking this current from the capacitors instead of the power supply (fat batteries) , therefore I didn't do it with simple H-bridge that cant supply such current.

    here is all the data sheet I have from the manufacturer:
    [​IMG]

    [​IMG]

    video: http://www.youtube.com/watch?v=e4--qDNGgQE

    Manufacturer web (if working): http://www.curobot.com/modules/news/print.php?storyid=19


    Somehow I destroyed this driver and its no longer respond to the 5v control pin (the white one), and always discharging without giving him 5v.
    for fixing it I needed the schematics of that circuit board.

    I asked from the manufacturer this schematics but he doesn't want to give me them, he wants me to buy a new driver kit (it cost 100$ and it's a lot of money) and I can't afford it. I have tryed to convince him but it doesn't help. I need schematics to fix it but also for my project post.

    I have tryed to replace two of the power transistors by new ones but still the same problem.
    Now I need you to give me tips and ideas how to figure out the schematics from the board it self.
    (creating schematics for the driver).

    I create an album of this driver for you could help me:
    ****************
    I can check any conections on the board just tell me which..
    The name of the transistor is: 62N25C
    The name of the voltage convertor (coil) is: coiltronics vp5-0155 46CH03
    Datasheet of this coil voltage convertor : http://www.cooperbussmann.com/pdf/453f0091-4eeb-4ee7-b33c-b689416a62c7.pdf


    I really need your help
    Thank you.
    ********************************************************************************************************************************

    [​IMG]
     
    Last edited: Apr 3, 2011
  2. JK-FlipFlop

    Thread Starter Member

    Jul 5, 2010
    111
    0
    Please help me.
     
  3. SgtWookie

    Expert

    Jul 17, 2007
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    The images you posted are not lit very well. It is very hard to take good photos of circuit boards. You must use very even lighting, or shadows and reflections will make it impossible to determine what one is looking at.

    Your board seems to have flux or perhaps a clear coat over it. Try cleaning it with 90% or better pure isopropyl alcohol and an acid brush (nylon bristles).

    Your board has two more transistors, Q3 and Q4, that look like they might be SOT-23 packages. You should look up the codes printed on them to find out what they are.

    D2 might be shorted or open.
     
  4. JK-FlipFlop

    Thread Starter Member

    Jul 5, 2010
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    Q3 & Q4 have very little codes on them I barely see them even with magnifying glass,
    I think the code of Q4 is "MCD" or "MCE" or "MC0" none of them bring results.
    about Q3 I cant see, its like the transistor melt on is surface and there is no code.

    there is other way to figure out what are they?
    thank you.
     
  5. SgtWookie

    Expert

    Jul 17, 2007
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    Well then, perhaps Q3 is defective.

    Don't know what it might be though, other than a transistor or MOSFET.

    You will need to try to construct a schematic from what's left of the circuit. Follow the traces around, see what components are connected by the traces, where power and ground connect, etc.
     
  6. JK-FlipFlop

    Thread Starter Member

    Jul 5, 2010
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    0
    I can check with multimeter the connections beteen components, it will take servel of hours. do you have any tips for constructing this schematics, where to start, Pay attention to which of the components...

    thank you.
     
  7. SgtWookie

    Expert

    Jul 17, 2007
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    Why don't you start off with whatever your "power rails" are (what are they? +5v and ground?) and what your output connectors are.
     
  8. JK-FlipFlop

    Thread Starter Member

    Jul 5, 2010
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    OK I will start with the input circuit or maybe all the lower layer.
    Tomorrow I will post it, I will try to add the values of the resistors, I don't know how to measure the value of the capacitors but I will put their name from the board.
     
  9. SgtWookie

    Expert

    Jul 17, 2007
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    Label everything, as best you can.
     
  10. JK-FlipFlop

    Thread Starter Member

    Jul 5, 2010
    111
    0
    Ok I constructed a schematic from this board from the lower side:



    [​IMG]

    Please analyze this circuit and then tell me what to do next...
    where to start solving in the upper side.

    Thanks.
     
  11. SgtWookie

    Expert

    Jul 17, 2007
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    Are you certain that the connections to Q2 are correct?
    You have the solenoid low side connected to the gate.
    I think it should be connected to the drain of the MOSFET (pin 3)

    Basically, move the current connection on pin 3 (drain) to pin 1 (source), the connection on pin 2 (gate) to pin 3 (drain), and the connection on pin 1 (source) to pin 2 (gate).

    Q3, Q4, and R9/R8/R10/RR are supposed to be some kind of gate driver circuit, but I think you have the transistors turned around.

    I would expect that part of the circuit to be some kind of emitter follower arrangement. I would also expect a low-value resistor to be between the transistors and the MOSFET gate.

    If Q4 is an MMBT4401 (NPN), then Q3 would likely be an MMBT4403 (PNP).
     
  12. JK-FlipFlop

    Thread Starter Member

    Jul 5, 2010
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    OK I probably mixed between the Q2 legs ( I know only collector,emitter and base) I guess its diffrent from the regular transistor. I will fix it.

    The MMBT4401 is my guess I dony realy know which transistor it is, there is any way to check it?

    thanks.
     
  13. SgtWookie

    Expert

    Jul 17, 2007
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    You look up the codes that are on the top of the SMD. If they don't cross reference to anything, you're kind of out of luck. They could be "house-marked" parts, which are meaningful only to the company that manufactured it.
     
  14. JK-FlipFlop

    Thread Starter Member

    Jul 5, 2010
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    Ok I fixed it.
    now I think Q4 must be PNP otherwise this cicuit won't work. Am I right??

    [​IMG]
     
  15. SgtWookie

    Expert

    Jul 17, 2007
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    That's somewhat better.

    The gate driver circuit needs a lot of work.
    R9 appears to be a 10k gate pull-down resistor; that's pretty typical.
    It would be less confusing to just show one end of it connected to the gate, and the other end directly to a ground symbol. Wires running everywhere are distracting.

    RR is not placed correctly. If SW1 is toggled, it would be between Vcc and GND, and not doing anything useful that I can tell. Perhaps it is supposed to be the base current limiting resistor for Q3.

    I don't see yet how Q2 gets turned on. There doesn't seem to be a source to do that.
     
  16. JK-FlipFlop

    Thread Starter Member

    Jul 5, 2010
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    Here is an example of how Q2 turned ON:

    [​IMG]

    Does this circuit do the same??
     
    Last edited: Mar 28, 2011
  17. SgtWookie

    Expert

    Jul 17, 2007
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    If the supply on the left goes to your cap bank and the supply on the right goes to 10v, then that would work. The 10k resistor keeps the MOSFET gate from "floating", which could destroy it.

    Perhaps transistors Q3/Q4 are part of an oscillator circuit.

    You haven't mentioned the supply voltage. I take it that you supply it with something like 10v or 12v, and it charges the caps to ~100v, and you then fire the solenoid by pressing the button. Right?
     
  18. JK-FlipFlop

    Thread Starter Member

    Jul 5, 2010
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    Yes the suply voltage is 12v, the controll pin connected to pic18 micro controller.
    I think it doesn't have enough current to turn on the mosfet and therefor Q3/4 darlington.
    About the upper circuit I think I found the little ic ocs, but it's too advanced for me...
    Please tell me what is it: http://cds.linear.com/docs/Datasheet/1871fe.pdf

    Thanks.
     
  19. kubeek

    AAC Fanatic!

    Sep 20, 2005
    4,670
    804
    It is a control circuit for boosting the voltage using that transformer or inductor.

    If the caps can get charged, you need to focus on the mosfet gate drive circuit. Most probably the problem is only a melted mosfet.
     
  20. JK-FlipFlop

    Thread Starter Member

    Jul 5, 2010
    111
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    Anyway I will need this board schematics for my project test, it's more important, therefor you are helping me constructing the schematics.
     
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