problems with microboost

• Dec 25, 2010

• #1

3zuli

0

Joined

May 30, 2009

Messages

810

Points

28

so I'm building my 445nm but I have problem with microboost. I soldered the 2 jumpers for highest range (540-1000mA), checked every connection with a magnifying lens and everything seemed ok but when I connected it on my testload and 18650, the current was first around 340mA and dropped to about 270mA after few seconds. now when I turn the pot, the current is changing from like 268 to 275mA:wtf:
so what should I do now?

there's also one thing: when I measured the value of that component marked yellow, it showed like 1ohm...

 

Attachments

• 
  microboost.JPG

  9.1 KB · Views: 213

Last edited: Dec 25, 2010

• Dec 25, 2010

• #2

Toaster

0

Joined

Aug 4, 2010

Messages

1,249

Points

0

Whats your power supply and test load consist of

 

• Dec 25, 2010

• #3

3zuli

0

Joined

May 30, 2009

Messages

810

Points

28

psu is one 3.6V 18650
testload 6x 1N4007 in series and one 1ohm resistor

 

• Dec 25, 2010

• #4

Toaster

0

Joined

Aug 4, 2010

Messages

1,249

Points

0

That is roughly (.7)*6+A=Vf

Makes sense? There is not enough juice Try 3-5 diodes.

 

• Dec 25, 2010

• #5

3zuli

0

Joined

May 30, 2009

Messages

810

Points

28

ok gonna try it :beer:

edit: tried 4 diodes, now it's going from about 360mA to 410mA and when it hits 400mA it starts to whistle :cryyy:

 

Last edited: Dec 25, 2010

• Dec 25, 2010

• #6

Toaster

0

Joined

Aug 4, 2010

Messages

1,249

Points

0

Yeah man, the less diodes, the higher the range should be.

 

• Dec 25, 2010

• #7

3zuli

0

Joined

May 30, 2009

Messages

810

Points

28

:anyone:

 

• Dec 25, 2010

• #8

Toaster

0

Joined

Aug 4, 2010

Messages

1,249

Points

0

Whistle? Nothing should be whistling. Lol Where is it coming from?

 

• Dec 25, 2010

• #9

3zuli

0

Joined

May 30, 2009

Messages

810

Points

28

from driver

 

• Dec 25, 2010

• #10

Toaster

0

Joined

Aug 4, 2010

Messages

1,249

Points

0

Well Yeah, Where on it?

 

• Dec 25, 2010

• #11

3zuli

0

Joined

May 30, 2009

Messages

810

Points

28

I dunno, I think it's comming from inductor...?

 

• Dec 25, 2010

• #12

Toaster

0

Joined

Aug 4, 2010

Messages

1,249

Points

0

I am trying to think why and component on a PCB would whistle. The only piece I ever had trouble with was on a cheap driver when a cap blew up. Can you take a picture, or video?

 

• Dec 25, 2010

• #13

3zuli

0

Joined

May 30, 2009

Messages

810

Points

28

I think nothing unusual can be seen on the driver... all solder connections are ok
but I still can't understand why it doesnt regulate in full range :thinking:

 

• Dec 25, 2010

• #14

3zuli

0

Joined

May 30, 2009

Messages

810

Points

28

:anyone:

 

• Dec 25, 2010

• #15

Kevlar

0

Joined

Apr 26, 2010

Messages

1,353

Points

48

Can you take you take a macro pic of your soldering job?

 

• Dec 25, 2010

• #16

3zuli

0

Joined

May 30, 2009

Messages

810

Points

28

here u r
(wires to LD are soldered temporary, because they go to test load. later I'll solder other wires, going to LD)

 

Attachments

• 
  P1010830m.jpg

  440.6 KB · Views: 220
• 
  P1010831m.jpg

  402.3 KB · Views: 246
• 
  P1010832m.jpg

  376.7 KB · Views: 290

Last edited: Dec 25, 2010