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Regarding Non-Negative Constant Drivers

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Mar 11, 2012
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Okay, so I've seen a LOT of great homemade or DIY drivers out there offered by the LPF community, especially Moh, but none of them have continuous negative/positive, so using the case pin is a no-no.
So, my question is this: how would I set up say, a C6 host with one of these drivers so that the driver isn't shorted by the case? Assuming I was going to do something along the lines of:

How would I make this work? Simply not solder the case pin to the negative? Yes, I have protective eyewear on the way, and I won't even start the build until I have them. Yes, I will practice safe lasing with this laser. Let the helping begin! :san::san::san:

EDIT: Some changes I will be making from the video's tutorial include using a diode press tool instead of the aixiz back, and I won't be ordering a "drilled pill" host from RayJob, just the machined flat one (so the whole host becomes the driver heatsink.)
 
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I've seen a LOT of great drivers out there offered by the LPF community, especially Moh, but none of them are continuous current

SJMoG.jpg


You must've misread something. Virtually all laser drivers (including the ones offered here) are constant current.
 
SJMoG.jpg


You must've misread something. Virtually all laser drivers (including the ones offered here) are constant current.

Sometimes I can be a total retard.... I meant to say non of the homemade drivers have continuous negatives... I was PLANNING on using Moh's Ben Boost driver for one of my C6 builds, but how would I set up the circuit if I cant use the case pin to draw the negative current? Now if I have another major stupidity outbreak like that, I will stick to flexdrives and mind my own buisness :banghead::banghead::banghead:
 
I reckon you mean this: A driver that either has the negative side of the diode connected to the batteries through the host, or the positive side.

Red laser diodes usually have their negative terminal connect to the case, and most hosts have the batteries negative terminal connected to the case too, so you need a 'high side' driver - i.e. a driver that limits the current between the postive terminal of the batteries and the laser diode. The typical LM317 driver is of this design.

For the 405 and 445 nm laser diodes it doesnt matter as those diodes are case-neutral: you can connect either the anode or cathode to the host, or neither, depending on what is most convenient in driver design. Most opamp based drivers are 'low side' drivers, requiring the diodes cathode to be isolated from the host.
 
C6 heatsink is isolated from the case.

You just hook the + and - inputs of the driver to the + and - of the contact board and the + and - outputs of the driver to the + and - of the diode.
 
C6 heatsink is isolated from the case.

You just hook the + and - inputs of the driver to the + and - of the contact board and the + and - outputs of the driver to the + and - of the diode.

Now THAT'S the answer I was looking for. Thank you all the others for the other information, it was related and helpful but Ben answered the question exactly as I wanted. THANK YOU. I'll see if I can rep +1...:thanks::thanks::thanks:
 
this is probably the most common occurrence with nubs coming through, getting their head around the continuous negative of drivers such as the flexdrive.
 
this is probably the most common occurrence with nubs coming through, getting their head around the continuous negative of drivers such as the flexdrive.

:crackup::crackup::crackup:
 
I guess the good news is that if you get any more nubs coming through you can just refer them to this thread instead of going through the motions again :D
 


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