FB3 XE voltage on 3 and 16 pin

Discussion in 'FB series of products' started by jsk, Apr 19, 2009.

  1. jsk

    jsk Active Member

    I have a FB3 XE and an QM2000.net basic working on one color laser
    Because of less 'power' on the FB3 XE in front of my QM2000.net
    I checked the voltage on my 3 and 16 pin on my db25...
    I have a 3.9 V (max, or so...) with my QM2000 and 2.9 V (max, or so...) on my FB3 XE
    Is this normal ? How can I have 3.9 V with the FB3 XE ?
    How can I use the configuration used with LiceQuick with LD2000 ?
    As usual, sorry for my English, hope you catch my answer :cool:
  2. jsk

    jsk Active Member

    one laser at a time not both laser working together on the laser
  3. aly

    aly Well-Known Member

    I really do not know how you have measured those voltage levels. I guess you have some sort of line-termination resistors inside laser projector. Because the voltage should be +5V at full brightness of the beam and 0V at blanking. Try to measure this without projector connected and with a frame without blank points (or with an oscilloscope).
    If the voltage drops, when the projector is connected, try to find those resistors and remove them. Resistors usualy have value 100 ohm to 120 ohm and are connected between those two signal lines (3 and 16) - differential pair.

  4. Pangolin

    Pangolin Staff Member

    I'd be willing to bet that you have been measuring the color outputs with a meter rather than an oscilloscope. If you search on this forum, you will find that I have discussed this far too many times.

    About the best and simplest and shortest way I can say this is that it's impossible to measure pulsed waveforms using a meter. And -- almost no matter what you do, the color signals will always be pulsed. Yes, almost no matter what you do -- to the point where I can almost say ANYTHING you do.

    So, basically the only way you can measure the voltage level of the pulses is with an oscilloscope. If you look with an oscilloscope, I am sure you will find our voltage levels to be within spec.

    Best regards,

    William Benner