I've been looking at the stickies and it looks like a lot of drivers offered my LPF members are out of production. I'm building a pen with an Osram PLT5510 diode which operates between 60-100mA at 5.4-7V, but most drivers I've found offer anything from 100mA and up, which is not ideal because I want to drive it under the maximum current. I'm also hopefully looking for a boost driver so I don't have to drive it with over 5v because I don't want the pen to use large batteries like two 18650s. Are there any drivers in production right now?
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Does anyone still make low mA drivers?
- Thread starter cosmonaut
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That particular diode should be okay to drive at 200 mA. That is still below fold over for that diode. It will still only give you an output under 100 mW, though.
Since this is boost/buck, I can run it either below or above the operating voltage of the laser, correct?
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Yep, I think this should work just fine; you may want to get input from more knowledgable members, or you could PM Jordan (DTR)to get his input on this particular diode/driver combination. 
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SEPIC drivers do work with either battery combinations, but won't necessarily regulate current the same in both configurations. Keep that in mind when you set it up.
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Hi,
You also have the Flex Drive V5 that will work with one Lithium ion battery. And is a little cheaper ..
Rich
You also have the Flex Drive V5 that will work with one Lithium ion battery. And is a little cheaper ..
Rich
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You're right about that, Rich, the only reason that I didn't mention it is that the maximum output voltage on the Flex Drive is 5.5V, and the Osram PLT5-510 runs from 5.4V to 9.0V.
I'm not sure if that would even be a problem with the OP running his pen at only 60-100mA; The Flex Drive may work fine.
I'm not sure if that would even be a problem with the OP running his pen at only 60-100mA; The Flex Drive may work fine.
Ooh, I might have to go with a Flexdrive in that case! I am wary however as the output voltage is hovering just above the operating minimum for the diode. Is it entirely possible the voltage could drop below 5.5v if the battery voltage dips slightly? In that case I would imagine I could power it with about 6.4v (using CR123s). Also, not much information is given in running the regulator in boost mode. Could it be done?