Spacelas PT-ITRUST board and Flexmod Analog Driver Issues

[no-esc]

I set the max Gain out at DR. Lava's board for my red (20ma), violet(60ma) and green(100ma) using a +5v supply to the modulation input as directed in the Lava Instructions.

Connected everything up to my PT-ITRUST dmx board.

Powered everything on.

Green and Violet were fine. Red one was extremely bright. Then turned into another LED (LOL).

decided to measure diode out at DR. Lava's board running the same test pattern using the dmx board as the modulation input signal.

Red was reading over 500ma??????????

I then the violet - 160ma?????
Green - 300ma

Luckily those last two were not out of spec for the diodes...


Has anyone else experienced this using the PT-ITRUST board and Flexmod drivers?

[drlava]

Hi, I'll repeat what was posted over on laser boy forum to your question:
"
The output current should not change from when you set it unless there is some other problem. Please check these things out with a multimeter:

-Actual output voltage of 5V power supply used for preset level
-main power supply voltage during preset (should not affect)
-main power supply voltage during operation (should not affect)
-resistance from - lead on power supply to - lead of diode, with the laser and PSU mounted on your baseplate
-resistance from - lead on power supply to + lead on diode, with laser and PSU mounted to baseplate
-output control voltage of PT board during the brightest test pattern

Also, how did you measure current during operation?
"

[kl79]

Take care ! some dmx board do not send 0-5V but 0-9V !!!!! (especially the V2 with 2 red leds)

And flexmods accept modulation from 0 to 12V...so if you have set 20mA @ 5V, what happen if you send 9V ??

[drlava]

The FlexMod N2's have protection so that modulation input voltages above 5.2V will not significantly increase output current, protecting the diode.

[shrad]

a folk at laserfreak had the same issues with flexmod N2 drivers and a chinese DMX board sending out 9V for full modulation, so this seems to be relatively common

drlava if you could help this out, it would be great, as we debugged this guy's setup thoroughly and found no clue but about the flexmod modulation being allowed over 5V