Dual flexdrive 1.6A

Just finished my first 1.2A build sunday night. After reading about the heft of the 445 diodes, I decided I wanted to crank it up, but I ran into some problems getting > 1.2A out of a single flexdrive: http://laserpointerforums.com/f67/micro-flexdrive-jumpers-64734.html

Long story short, wired two in parallel, one thermal glued under the pill, one on top. The one on the underside was set to 900ma, and the one on top 700ma.

The result? 1.63A measured inline with the running diode. I'm pretty stoked, but still confused as to why I couldn't get a single flexdrive to do this for me.

Here are pics of the build: Index of /dont_lase_me

The pics of the dual flex drive setup start at 0640. op:

PS. For anybody trying to remove a component glued with Arctic Alumina, put it in the freezer for a bit. It only took about 10 mins in an anti-static bag on top a bag of ice.

Similarly, when waiting for it to harden, put it under a hot light. It only took about 15 minutes to get a handleable bond.

goosesensor said:

Just finished my first 1.2A build sunday night. After reading about the heft of the 445 diodes, I decided I wanted to crank it up, but I ran into some problems getting > 1.2A out of a single flexdrive: http://laserpointerforums.com/f67/micro-flexdrive-jumpers-64734.html

Long story short, wired two in parallel, one thermal glued under the pill, one on top. The one on the underside was set to 900ma, and the one on top 700ma.

The result? 1.63A measured inline with the running diode. I'm pretty stoked, but still confused as to why I couldn't get a single flexdrive to do this for me.

Here are pics of the build: Index of /dont_lase_me

The pics of the dual flex drive setup start at 0640. op:

Click to expand...

My guess is your test load is wrong or your batteries are wrong. Flexdrives have a 1500mA max 1200mA means its either broken, your power input it wrong or your measurements are wrong.

EDIT: Did you fiddle with the POT quite a bit trying to set the current?

Helios said:

My guess is your test load is wrong or your batteries are wrong. Flexdrives have a 1500mA max 1200mA means its either broken, your power input it wrong or your measurements are wrong.

EDIT: Did you fiddle with the POT quite a bit trying to set the current?

Click to expand...

There was definitely some question over the test load. I used 4 1N5406 diodes and a 4W 1Ohm resister. However, I began just checking the current inline with the diode.

Also, I used two different brand new flexdrives... So until I wired them in parallel, I figured it was most likely a battery problem (18650 AW). I guess since I'm getting 1.6A measured inline with the operating diode, I can rule that out. Weird, I know.

And about the pot, yeah, I fiddled with both of then quite a bit. :thinking: