Strange Shift in Amp Draw when measuring

[kosPap]

Hi all!
I have a problem when I am measuring the current draw of a MC-E dropin when installed in my SF 9P.

The dropin alone consumes around 3.3 Amps...When inserted in the flashlight (I use a AW17670) and the DMM lead lightly touches the batt neg pole I get essentailly the same reading...

But when I press harder and the batt moves inward I have a jump to 4.4A consumed (it may ne of importance but this was also the number I got when I DDed the LED before assembly)

Some more data. this is the bare dropin i used, and this is the driver...
The driver has a pos spring installled and only a single coil of the neg pouter spring is used from proper contact with the flashlight body..

so what may be happening?

 

[VidPro]

sounds like you already know what is happening.
if i was to GUESS, the sides or top of the board are connecting to the pill somewhere and shorting out into a DD.

check your spring, compress it down, and see if its hitting somewhere it shouldnt, see if the spring is EVER capable of hitting something it shouldnt.

insulate something, or grind more off the board edge, and then make sure you secure it still, so it doesnt bump around and cause that or other problems.
you can often take about 1mm off the round of many of the boards, as long as you look carefull at what is happening, and then (again) insure that no Foils of the board are contacting the edge of the pill thingee, in the wrong place.
so if you need to adjust it, there is a lot of capability to do that.

Insert insulator rings wherever needed, tight cardboad rings used for some plumbing stuff , or gasket making materials, or just cutting up a transparency sheet or something, can make an insulater.
epoxying stuff in so it doesnt budge , testing it often, you can also POT stuff with epoxies to assist in the heat removal from the driver. problems with that is it is often too permanent, but if you test often before cure, you can lock it into a good place.
Lock things up by doing soldering on the edges, so nothing moves, at least with solder you can remove that

it just depends, your astute, alert and aware, so your 99% there, just mess with it some more than Lock it down so it doesn't budge for the rest of its lifetime.

 

[kosPap]

just a moment...are we supposed to solder the board rim to the pill?

how all these apply to the pad of this board?
http://www.kaidomain.com/UploadFiles/633730238021718750.JPG

both the 4 and the 2 smaller ones wrap over the other side...

 

[VidPro]

just a moment...are we supposed to solder the board rim to the pill?

how all these apply to the pad of this board?
http://www.kaidomain.com/UploadFiles/633730238021718750.JPG

both the 4 and the 2 smaller ones wrap over the other side...

ummm, i donno you got the meter.
often the side edge thing is soldered to the pill because then it has to make the connect to the negative, just depends on the driver.

and often the positive side (center) just is Passed through direct.
so the positive is sorta like the "ground" an many of these things, just connected straight through, so GUESSING it is probably the negative side shorting somewhere.

and you often have to dremmel off the Mold bits, where they cut it away from the other boards, there will be PCB stuff sticking out where it doent need to be, getting in the way of proper seating.

the real Picture that would be helpfull is the picture of YOUR project and driver, as sometimes the sales sites dont even have the right picture in them, or the design has changed slightly.

 

[VidPro]

using the same site here, look at thier pic, the 4th one, the spring is soldered to the outter ring.
http://www.kaidomain.com/ProductDetails.aspx?ProductId=6436

or look at these pics for the solar force drop in, same idea.
http://www.kaidomain.com/ProductIma...86&url=UploadFiles/633546203798481250_med.JPG

hey that is surley looking like i did it
the spring IS enough to make the contact to the grounding, mostly.
the problem will be if a Foil on the board is making contacts to the negative that it shouldnt, effectivly shorting out the driver and making direct contact. or possibly even a short from the postive center spring compressing down and hitting something and doing a really bad short (pole to pole).

 

[kosPap]

I believe I have made everything Ok...it is not the first module I have assembled...But I will be shooting apic this afternoon and posting it soon...I will aslo test batt pressure on a the module alone..

thanks so far...Kostas

 

[Justin Case]

Your KD driver is a direct drive, PWM controller. More pressure might simply be reducing contact resistance.

 

[kosPap]

hmmm exactly....I did a test by pressing the batt right one the spring..somehow the driver gave inwards increasing draw...problem solved

But now I have another question on this driver ..and I should be continuing it in this thread...