Low 1V Dropout cheap 'Groove' driver kits

yeah that would for sure work.

one problem i have been encountering is the pads are sometimes very covered by the coating and i cant get a good solder connection. (mostly on R1)

but can someone please make measuring the output idiot proof.

as said above and how i thought you should,
but this is how im doing it...
i put the DMM probes on each side of the 1 ohm resistor and i have it set on 200ma. but i get no reading.
i have a 9 volt hooked up to it and no diode or test load.

i have tried this on two different boards i have assembled

let me know if im doing something wrong.

thesk8nmidget said:

yeah that would for sure work.

one problem i have been encountering is the pads are sometimes very covered by the coating and i cant get a good solder connection. (mostly on R1)

but can someone please make measuring the output idiot proof.

as said above and how i thought you should,
but this is how im doing it...
i put the DMM probes on each side of the 1 ohm resistor and i have it set on 200ma. but i get no reading.
i have a 9 volt hooked up to it and no diode or test load.

i have tried this on two different boards i have assembled

let me know if im doing something wrong.

Click to expand...

You need to measure the voltage in mV across the 1 ohm resistor. You should also put in a small test load also, even if it's just a 20 ohm resistor.

or short the output together with no load. A led works best though cause you can tell when it's truly workin.

well with no resistor i dont get any voltage when i measure it. then if i put a 10 ohm resistor ( the only one i have) i get a constant 110mv even when i adjust the pot

thesk8nmidget said:

well with no resistor i dont get any voltage when i measure it. then if i put a 10 ohm resistor ( the only one i have) i get a constant 110mv even when i adjust the pot

Click to expand...

I had a weird problem like this as well. It turned out to be that I had to have a diode connected to get the correct power reading. No idea why.

sk8er4514 said:

I have never heard of a positive body LD, are you connecting a PHR803T + to the 'not used' body pin?

Click to expand...

All very high power diodes are case positive. Like high power IR pumps in green lasers. Or high power multimode 635nm diodes. The die is turned around, so the hot side is facing the pedestal, and the heat doesn't have to flow through the die first, before dissipating into the pedestal and the base.

Basically it's rotated around so it doesn't cook itself.


TheMonk:
For things like that you need a common anode driver (and the battery turned around). I have one such driver fom a CNI pen. It has an amazingly low dropout voltage of only 0.39V!  That would be an amazing driver to have. Especially if it could work in common cathode config...

But there is a cheaper solution. AMCs are good for common anode applications. However, if you use the original AMC board, you have to change/remove the polarity protection, or it doesn't work with an output cap! I've been driven nuts with the AMCs before i figured out why they don't work with an output cap (and you don't want to be without!) Out of 30 AMCs i only found 3 that worked with a cap on the LD, without removing the polarity protection diode from the board first.