HELP with driver!

[grainde]

I've just received my AMC 7135 1050 mA driver from Kaidomain and I want to modify it to 750 mA, in preparation for the new laseerer 3.8 mm diodes!

Here is the driver I bought, for anyone who might be interested.: http://www.kaidomain.com/product/details.S009743

I know I have to remove one 7135 chip from the board, but as there are 3 to choose from, I'm not sure which one. I guess they're all in parallel and it doesnt really matter, but I thought I'd check just to be sure! The one in position Q2 would be easiest, as it is the most accessible...Any thoughts??

Any help / comments would be much appreciated! :thanks:

 

[justinjja]

Re: Help with driver!

Yes you can remove any of them,
For heatsinking purposes I would remove the one in the middle,
so the other 2 are spread out more

I've just received my AMC 7135 1050 mA driver from Kaidomain and I want to modify it to 750 mA, in preparation for the new laseerer 3.8 mm diodes!

Here is the driver I bought, for anyone who might be interested.: http://www.kaidomain.com/product/details.S009743

I know I have to remove one 7135 chip from the board, but as there are 3 to choose from, I'm not sure which one. I guess they're all in parallel and it doesnt really matter, but I thought I'd check just to be sure! The one in position Q2 would be easiest, as it is the most accessible...Any thoughts??

Any help / comments would be much appreciated! :thanks:

 

[grainde]

Re: Help with driver!

Ok thanks for the reply! :beer:

I have three boards and removed 1 chip from 2 of them. I now have a new problem... The process went smoothly and I didnt damage, overheat, or bridge any contacts. On my test load on the 445 (4th pin) setting I get 700 mA, but if I go to the red diode setting (pin 3) I get 1.3A!! This was the same for both modified boards! As I plan to use this for a red build with a max recommended current of 750 mA, I think the diode may have a problem!

Also with the 3rd board, which I didnt touch, I get exactly the same readings on the pins! Ie 750 mA and 1.3A?

Have included a couple of pics...D1 was (+) and Q3 (-) according to kaidomains website.

Anyone know whats wrong?

 

[justinjja]

Re: Help with driver!

That is strange, 2 of those chips shouldn't be doing 1.3A

How are you powering the driver?

Got a pic of your testload hooked up and measuring?

 

[Blord]

Re: Help with driver!

Did you look closely at the modified boards. Maybe you shorted something.

My driver had 3 ic which give me an output of 1050mA. After removing one ic the output dropped to 700mA like expected.
The driver has 1 mode and came from DX.

 

[grainde]

Re: Help with driver!

Was using a panasonic 18650 to power it and a kit from Jufran88 http://laserpointerforums.com/f39/fs-selectable-test-load-up-3a-assembled-diy-kit-stock-63450.html
Setup should be fine as Ive used it a few times and never had problems, but if you still want to see it I can take a pic?

 

[justinjja]

Re: Help with driver!

blord is probably right then

 

[Blord]

Re: Help with driver!

Maybe the multi mode chip doesn't like to run on two AMC7135.

Mine was just like this driver. It has less components.

http://dx.com/p/6v-5w-cree-circuit-board-for-flashlights-16-8mm-3-1mm-26109?item=9

 

[grainde]

Re: Help with driver!

Did you look closely at the modified boards. Maybe you shorted something.

My driver had 3 ic which give me an output of 1050mA. After removing one ic the output dropped to 700mA like expected.
The driver has 1 mode and came from DX.

Hi Blord. Yeah I looked under a magnifying glass and couldn't see any shorts.:thinking: Its strange though that all three boards give the same values ie 750 and 1.3 A, even though they have a different no. of chips.

I'm pretty certain its not shorted because on the 4 pin setting its stable at 700 mA for all 3 boards? I shan't talk about modes cos I don't think those are working either...

 

[grainde]

Re: Help with driver!

Maybe the multi mode chip doesn't like to run on two AMC7135.

Mine was just like this driver. It has less components.

6V 5W Cree Circuit Board for Flashlights (16.8mm*3.1mm) - Worldwide Free Shipping - DX

I dont think so because a few people eg AnthoT (and I think AUS? or Fiddy?) have already done this. AnthoT reported hed lost the modes when hed bridged something and when he removed the solder the modes worked again. His board was a 1050 and he made it into a 700 mA in a similar manner.

Edit: Sorry double post

 

[Blord]

Re: Help with driver!

try remove another AMC7135 and see what happens then. It should do 350mA.

 

[grainde]

Re: Help with driver!

No good I cant reflow and it will be very difficult to put a chip back!
I have 3 diodes coming and I wont have enough drivers if I cant repair it! Shipping from Kaidomain took just over 3 weeks too, so I dont want to have to order more!

Edit: the chips do 700 mA, but only at the 445 diode setting. If I move to the red diode setting I get the high current, which is the problem...

 

[foulmist]

Maybe it is switching to direct drive at lower forward voltage (aka red setting).

How many diodes is your red setting on the test load? :thinking:

Maybe it is the chip I am not sure.

 

[Jufran88]

I think I see the problem. You have the black wire connected to BATT negative. It should be connected to the LED negative pad.

Just switch the location of the black wire and it should work fine.

 

[grainde]

I think I see the problem. You have the black wire connected to BATT negative. It should be connected to the LED negative pad.

Just switch the location of the black wire and it should work fine.

Ah ha fantastic! :thanks: Ill try that!

Just so you all know this is from the Kaidomain website....

How to use:
Hock up negative wire at Q3 and postitive wire at D1 to use

So if this works, their wiring info is wrong! :gun:

Thanks for all the help, will report back!


Edit Foulmist the red setting ie pin 3 has 3 diodes. Sorry forgot to mention it.

 

[justinjja]

Worth a shot,
But iirc the 7135 chips work with a common ground.

I think I see the problem. You have the black wire connected to BATT negative. It should be connected to the LED negative pad.

Just switch the location of the black wire and it should work fine.