Connect with us

Power supply problem on touchscreen contoller

Discussion in 'Electronic Repair' started by [email protected], Nov 22, 2012.

Scroll to continue with content
  1. Guest

    I have an old IRIS 4d/35 system with touchscreen capabilities and display is CRT type.

    Recently we upgraded the system to run on LCD displays where we needed to provide the touchscreen controller with a separate power supply since the power for the controller was previously drawn from the CRT power supply.

    However when a new switching power supply was used the touchscreen did not work. Reverting back to the supply from the CRT works flawlessly.

    The supplies required for the touchscreen controller are 12V, -12V and 5V. The CRT power supply had a common ground and so does the new switching power supply.

    Any idea what could be the problem with the new power supply. Any advise would be very much appreciated.
     
  2. Guest

    I've checked on this and this is what I found.

    The original power supply is proving 5V - 2A, +12V - 0.3A, -12V - 0.2A
    While the replacement power supply 5V - 4A, +12V - 2A, -12V - 0.5A

    Has the common ground of the +12V and +5V effect on the -12V in anyway?
     
  3. mike

    mike Guest

    What do you mean by proving?
    Do you mean "reading the labels on the power supplies?"
    With the system operating, what voltages did you measure?
    If you got the right voltmeter readings, look with a scope
    to see if it's really DC.
    Power supplies have a minimum load requirement. Sometimes
    that's supplied inside. Other times, you're required to provide
    some minimum external load for everything to work out right.

    However when a new switching power supply was used the touchscreen did
    not work. Reverting back to the supply from the CRT works flawlessly.

    Exactly what was the symptom of "did not work?"

    Does this mean that you left the touch screen attached to the LCD and only
    swapped out the power supply?

    Depending on the mechanical configuration, noise from the LCD backlight
    might
    affect the touch screen. You can check this by distancing the touch
    from the lcd.
     
  4. Guest

    The touchscreen did not respond to any touch inputs.
    Yes that's what I did.

    Will check the output with a scope since the voltages are not far apart in comparison.
     
  5. N_Cook

    N_Cook Guest

    provide the touchscreen controller with a separate power supply since the
    power for the controller was previously drawn from the CRT power supply.
    not work. Reverting back to the supply from the CRT works flawlessly.
    5V. The CRT power supply had a common ground and so does the new switching
    power supply.
    would be very much appreciated.

    Does the touchscreen use a high "static" voltage (ultimately via the CRT
    accelerating voltage) as part of its operation ?
     
  6. Guest


    When we upgraded from CRT to LCD the touchscreen was upgraded at the same time. I suspect the problem is with the power supply as reverting back to the original solves the problem.
     
  7. somehow your post was stuck somewhere for about 15 years.

    not sure about the touch screen problem though.

    I have to ask- what is this thing still being used for??
     
  8. Guest

    Will check on the sequence on power up, thanks Jon.
     
  9. Guest

     
  10. Guest

    Cydrome,

    the 4d/35 is being used on a flight simulator. The company is planning to replace the iris system but I would still have to maintain the old simulator.
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-