Miccim again: Got all parts and light but something is wrong.

[Miccim]

Hi again.

I finally got all parts together but i cant get the flex mod to work as intended.

I connected a computer psu:

Positive 12V- dc to the V+

Negative to the G

So far soo good?



I then soldered a wire from the Inter lock to the V+

The flexmod starts with a red light.

Then the problems start.

What to do now? if i connect my amp meter to the outputs i can only turn the bias, to get a reading. From zero and up. Turning the gain dosent help.

I connected the diode to see what happened and i could only se more or less light turning the bias. Nothing happened when i tried the gain.


I can see in this guide that there is soldered a resistor to the m+ It dosent say anything about that in the normat manual for the flex mod?

Do i have to use the M+ hole at all? if, what do i do with it please?

Regards Miccim

[colouredmirrorball]

Don't you need to apply a modulation signal as well? I'm not familiar with your version of the Flexmod, but normally you have V+ and G for the power supply, and Mod+ and Mod- for the modulation signal. If you were using a 5V power supply you could just attach Mod+ and Mod- to the PSU for testing, but since you have 12V you need something else. See if you can find a 5V source. Or hook it up to your DAC if you have one, and apply a constant signal at full power to the colour channel.
If you don't connect anything to the modulation input, the laser will be switched to "off", ie. it will receive the amount of current you have set with the Bias pot. Normally you want to set this to somewhere right below lasing. When the full 5V is applied then the diode will receive the max current you set with the Gain pot.

[swamidog]

yes. a flexmod won't work without wiring up the modulation inputs.

for initial testing and calibration, wire M+ to ground.

Don't you need to apply a modulation signal as well? I'm not familiar with your version of the Flexmod, but normally you have V+ and G for the power supply, and Mod+ and Mod- for the modulation signal. If you were using a 5V power supply you could just attach Mod+ and Mod- to the PSU for testing, but since you have 12V you need something else. See if you can find a 5V source. Or hook it up to your DAC if you have one, and apply a constant signal at full power to the colour channel.
If you don't connect anything to the modulation input, the laser will be switched to "off", ie. it will receive the amount of current you have set with the Bias pot. Normally you want to set this to somewhere right below lasing. When the full 5V is applied then the diode will receive the max current you set with the Gain pot.

[Miccim]

Ok,

So in a computer psu theres also 5v out too. So i have to apply 5v to the M+ on the flexmod, and then apply the black ground/negative from the psu to the G, on the flex mod?

So actually the flexmod have to regulations: One is the bias input power and the other is gain power. Both with a powersupply on their own so to speak, and the resistor in the other guide for a handheld laser is applied because in a handheld laser there is only one powersupply? Hope im getting it right

Regards Miccim

[colouredmirrorball]

I think your view is kinda wrong :P
The Flexmod takes the current from the PSU to power the diode, and the modulation signal to regulate the amount of current it delivers to the diode. When the modulation signal is 0 V, it delivers a small amount of current (the offset current or "bias", you can adjust this with the bias pot). When the modulation signal is 5 V, it gives the full amount of current you set with the Gain pot, but still using the electric power it got from the PSU.
The modulation signal is only to control the current that goes through the diode, so it doesn't matter if the source of this signal doesn't provide a lot of current, because it's only the voltage that matters. A DAC delivers a variable voltage between 0 and 5 volt, but only a few milliamps of current.