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

LPF Donation via Stripe | LPF Donation - Other Methods

Links below open in new window

ArcticMyst Security by Avery

NOO!!






Cyparagon

Cyparagon

0
Joined
Sep 12, 2007
Messages
9,399
Points
113
I'm beginning to think this capacitor that pervades many driver designs does more harm than good.
 
Alexizupinhea

Alexizupinhea

0
Joined
Mar 25, 2008
Messages
1,007
Points
38
No... u need the cap. It seems like the diode can't live with it, can't live w/o it.
 
billg519

billg519

0
Joined
Feb 21, 2008
Messages
1,056
Points
0
The output capacitor causes problems because it will charge up if the diode is disconnected for any reason, then if the cap is not discharged before hooking up the diode again, the cap will overcurrent the diode, killing it.
The fix is simple. Put a resistor (I use 470 ohm 1/4 watt) across the cap, so the cap is discharged whenever power is turned off. No more forgetting to discharge the cap when installing a diode. Works for me.
 
Alexizupinhea

Alexizupinhea

0
Joined
Mar 25, 2008
Messages
1,007
Points
38
wow... sounds like a good fix if thats how it works. I wonder how that affects the circuit in terms of how it affects the amount of current going out. Since that hookup would be parallel, I would think that that will affect the current, but I don't know by how much (too lazy to do the math).
 
M

Mario_cro

0
Joined
Dec 20, 2007
Messages
31
Points
0
i think its best to solder cap directly to diode thats how i did it cause that way he can't be charged without diode and wont kill it
 
Alexizupinhea

Alexizupinhea

0
Joined
Mar 25, 2008
Messages
1,007
Points
38
I have to say, I'm liking this thread. It's helping me learn so new tips which are useful. Soldering the cap directly to the diode sounds like a good idea, I'll do that next time for sure. Also, I was wondering, what can I do to prevent the diodes from being harmed by ESD? I have a feeling my last two diodes died either from ESD or from putting resin epoxy on the leads after soldering to them.
 
rog8811

rog8811

0
Joined
Jul 24, 2007
Messages
2,749
Points
0
Puting epoxy on the leads should not be a problem, ESD could.

Get or make an earthing strap which you can clip onto the chassis at the rear of your computer.

Regards rog8811
 

Attachments

  • ESD_strap.jpg
    ESD_strap.jpg
    70.1 KB · Views: 54
daguin

daguin

0
Joined
Mar 29, 2008
Messages
15,989
Points
113
Alexizupinhea said:
I have to say, I'm liking this thread. It's helping me learn so new tips which are useful. Soldering the cap directly to the diode sounds like a good idea, I'll do that next time for sure. Also, I was wondering, what can I do to prevent the diodes from being harmed by ESD? I have a feeling my last two diodes died either from ESD or from putting resin epoxy on the leads after soldering to them.
Click to expand...


ALWAYS wear an anti-static wrist band when working building lasers. I usually keep mine on from the moment I sit down to start taking out the components until I close up the host. It probably isn't needed after the driver is attached to the diode, but why take the chance? It doesn't cost me by the minute ;)

I also store all of my components in anti-static packaging.

Peace,
dave

@ DayOfShadows -- It may have only been "mostly dead" ;) (points for the source)
It seems to be full of life again.
 
Alexizupinhea

Alexizupinhea

0
Joined
Mar 25, 2008
Messages
1,007
Points
38
Yea... then I have a feeling I broke all my diodes because of ESD. I'll be much more careful from now on. I might buy some more PHR-803t diodes now from Jake who is selling for $11.50 again (I didn't realize he was selling before for $11.50 so I bought from Blu-Ray for $13). Anyway, Is there an easy way to make sure my circuit components are protected from ESD? Like, I already built a DDL circuit, so could I just touch all the leads together on a big piece of metal, then it'll be ok? Sorry for all the questions, but I never knew much about ESD untill now. I guess I'll read wiki a little.
 
D

DayOfShadows

0
Joined
Nov 6, 2008
Messages
866
Points
18
daguin said:
@ DayOfShadows -- It may have only been "mostly dead" ;)  (points for the source)
It seems to be full of life again.
Click to expand...
Ok ill delete my post saying thread closed if i have too :p :) ;)
 
daguin

daguin

0
Joined
Mar 29, 2008
Messages
15,989
Points
113
You must log in or register to reply here.




Top