FB3 XE voltage on 3 and 16 pin

jsk

jsk

Active Member
Hello,
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:
Thank's
 
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.


Intensity/ Blanking
This is intended for use by projectors which use an intensity signal or scanner blanking. This is a unipolar analogue signal whose voltage range is 5V peak-to-peak differential.
A differential voltage level of 0V indicates zero intensity and that the beam is fully blanked. A differential voltage level of +5V indicates full intensity and that the beam is not blanked.
Click to expand...
 
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
 
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