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

LM317 driver Capacitor

Joined
Feb 25, 2011
Messages
68
Points
0
I have all the parts for lm 317 driver and i have question
wich capacitor i need for driver?
parts are:
3ohm 1/2w resistor
lm317T
1n5819 or 1n4007
and 22mF 25V capacitor
soon i'll get breadboard i'm waitin for shipping
is it ready to assemble?
and can static electricity from my hand kill these parts?
 
Last edited:





anselm

0
Joined
Nov 22, 2010
Messages
2,448
Points
0
static is very unlikely to kill parts of your driver, but laser diodes are very sensitive
to static discharge.
You don't need a capacitor, in fact the simplest LM317 driver has no parts other
than the LM317 IC and a resistor.
The diode is just used to protect from reverse polarity, the (input) capacitor is supposed
to filter noise from the power source.
An output capacitor is supposed to stabilize the output of the LM317, but I found
that you don't need any, it is stable as it is even without a output capacitor.
 

Kevlar

0
Joined
Apr 26, 2010
Messages
1,353
Points
48
The capacitor you have listed will work fine. If you choose to incorporate the cap in your build be sure to discharg it before. Connecting your driver to your LD.
 

Asherz

0
Joined
Jan 18, 2009
Messages
1,623
Points
0
In answer to your question I believe in the original tutorial it was a 16V 47uF Cap. Anyone feel free to correct me if I'm wrong.
 
Last edited:
Joined
May 4, 2009
Messages
5,443
Points
113
That cap will work fine and if you put a high value resistor like a 3000ohm acros the cap it will help discharge it when power is removed and that will help to keep from blowing up your diode, it's not nessary though.

in order to kill them parts with static you would have to drag your feet on the carpet and build up a great big charge, not likely your going to kill them with static.
 




Top