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Old 07-22-2014, 06:22 AM #1
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Default M140 driver

Hello!

I am trying to build a driver for my M140 laser diode. I made a circuit following guide on this site. Then I made a test load. When I change the pot value to the minimum I get a maximum current of <100mA on the 1ohm resistor.

Can someone please explain why the maximum current is only <100mA?

Thank you in advance!
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Old 08-02-2014, 04:56 AM #2
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Default Re: M140 driver

I'm no expert, but I know when I built my dummy load for my M 140, I only used 4 of the 1N4001 diodes. My guess would be to remove one Diode and see where that puts you. But that is only an educated guess, and I'm not an electronics expert.

EDIT: Here is the dummy load I built if that helps: Dummy Load & Batteries for M140?

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Old 08-02-2014, 06:09 AM #3
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Default Re: M140 driver

7V input - 1.25V sense resistor - 1.75V (?) dropout voltage = 4V left for your diode (or test load simulating a diode).

Not enough voltage.
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