Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

How to Register on LPF | LPF Donations

First rkcstr death.

Joined
Sep 1, 2009
Messages
108
Points
0
The learning curve is a bit more then I thought. Then again theory and practice can be two different beasts. I had built my first dummy load and then stepped down the volts with another small board. I set it at just under 400mA for the LC diode and soldered on my main leads. I did one last test before hooking up the LD and it smoked and flashed. Looks like the solder bleed through a bit too much.


messup.jpg


Anyone know a better way to drop voltage btw? Daisy chaining 1n00* diodes takes up a bit much room.
 





always make sure your solder job is fairly neat before applying power. i fried the resistor one mine one time.. if you just got too much solder around the cap on the back that shouldnt have caused it to fry.. it would have just bypassed the cap and offered less protection from spikes. you had to have bridged something else...
 
This is what it looks like now. The Cap is a little toasted. The white part was the major flash. Any idea what the white part is? Resistor?

now.jpg
 
the part marked with white is a mosfet but i dont remember what kind. send ryan(rkcstr) a pm and see if he can send you parts to replace them with. if it can be fixed then fix it or buy another driver. the part that "fried" was definately the mosfet though..
 
That is the reverse polarity mosfet maby you hooked it up backwards ? :thinking:
 
Yup, that point you bridged is essentially the post-MOSFET positive side to negative side of the battery. So, essentially the battery was shorted through the MOSFET, which is a huge current through the small part and caused it to fail and give you that nice white flash and smoke.

The cap should be OK (maybe just some residue from the MOSFET) since you essentially shunted all the current around it by bridging across.
 
Last edited:


Back
Top