Laser pointer discussion. Read/write reviews of laser pointers and laser pointer companies. Learn about all types of laser pointers and lasers





Welcome to Laser Pointer Forums! If you are looking for a laser pointer or want to compare different laser pointer companies, you may want to check out the LPF Laser Pointer Company Database. The link will open in a new window for your convenience.








Green Laser Pointers by Category Blue Laser Pointers by Category Red Laser Pointers by Category
Yellow Laser Pointers by Category Violet Laser Pointers by Category Orange Laser Pointers by Category
Top Laser Pointers by Power - 1 Watt+ Top Laser Pointers by Power - 500mW+ Top Laser Pointers by Power - 250mW+
Laser Pointer Database High Power Laser Pointers Laser Pointer Diodes
Laser Technology Laser Pointer Parts Lasers by Wavelength
Top 10 Laser Pointer Companies Laser Pointer Company Database Visible Beam Laser Pointers


One laser store meets all your needs

























Go Back   Laser Pointer Forums - Discuss Laser Pointers > Lasers > Drivers, Test-load, Power Supply, & Batteries



LPF List of Laser Pointer Companies (link opens new window)



Reply
 
LinkBack Thread Tools Display Modes
Old 03-21-2011, 04:24 PM #1
Junior Member
 
Join Date: Jan 2011
Location: The Hammer
Posts: 19
Rep Power: 0
Zenador will become famous soon enoughZenador will become famous soon enough
Zenador Zenador is offline
Junior Member
 
Join Date: Jan 2011
Location: The Hammer
Posts: 19
Rep Power: 0
Zenador will become famous soon enoughZenador will become famous soon enough
Default Characteristics of Batteries vs. Wall Warts

Hey guys - and sorry for the semi-long post,

I'm building (copying) a couple builds from others here on LPF. For testing my first crude test builds, I've been using variable voltage wall warts, but my final builds will use 2 Li-Ion 10440. I've stopped my work, as I'm unsure if there will be differences between the Li-Ion's and constant DC power supplies.

The builds are two ST phasers, LM317 driver for the PHR on 2x Ultrafire 10440 3.6v. The original sound board will be run from a 3v button cell, and the LED output will be tapped and run to an SCR (2n5060) acting as the switch for the 317. One of these phasers is a gift for my brother (big trek fan) for being my best man a few weeks ago, so I don't have time to blow up parts and re-order... (yes I bought him safety glasses)

As I'm still waiting for my battery order to arrive, I've stopped working on them. I'd like to start it up again, but am hesitant on the differences between the 2 power sources... Does anyone have experience switching safely from one to the other without having to re-test the driver current/voltage?

Cheers,

Zen


Zenador is offline   Reply With Quote







LPF List of Laser Pointer Companies (link opens new window)







Old 03-21-2011, 05:01 PM #2
Class 3R Laser
 
Join Date: Nov 2010
Location: Portugal
Posts: 2,470
Rep Power: 84
anselm has a reputation beyond reputeanselm has a reputation beyond reputeanselm has a reputation beyond reputeanselm has a reputation beyond reputeanselm has a reputation beyond reputeanselm has a reputation beyond reputeanselm has a reputation beyond reputeanselm has a reputation beyond reputeanselm has a reputation beyond reputeanselm has a reputation beyond reputeanselm has a reputation beyond repute
anselm anselm is offline
Class 3R Laser
 
Join Date: Nov 2010
Location: Portugal
Posts: 2,470
Rep Power: 84
anselm has a reputation beyond reputeanselm has a reputation beyond reputeanselm has a reputation beyond reputeanselm has a reputation beyond reputeanselm has a reputation beyond reputeanselm has a reputation beyond reputeanselm has a reputation beyond reputeanselm has a reputation beyond reputeanselm has a reputation beyond reputeanselm has a reputation beyond reputeanselm has a reputation beyond repute
Default Re: Characteristics of Batteries vs. Wall Warts

If you're using the good old LM317 driver, I'd say you're quite safe.
That IC will always put out the current you set it at with the resistor between
'output' and 'adjust', as long as it has enough voltage on it's input.
Some drivers deliver different amounts of current, depending on the diode's forward voltage
and/or the input voltage to the driver, but not so the LM317.

Only two things can throw it off:
1. you don't have enough extra voltage (Diode's Vf + ~2V for the LM317) on the input,
in that case the driver simply delivers less current that it's supposed to, so it's safe.
2.When the input voltage is much higher than what the diode needs, the LM317
can get quite hot, which can be countered by heatsinking the IC, and/or adding
silicon rectifier diodes (the 1N40xx kind, for example) before the input, lowering
the voltage by about 0.7V each diode.

If anything, the batteries are safer than the wall transformer, because they are a quite 'smooth' power supply.
__________________
I'm away from home and lasers until late July!
Kryton Groove switch workaround
Get your warning label stickers 0.90$ or less, depending on qty
The INDEX to the LPF
Add to it, and spam it from your signature, too!
Beware! Scams a-plenty, don't be a sucker!
___________________________
ATTENTION
This forum is fullfilled mit special electronische equippment. Fingergrabbing and pressing the cnoeppkes from the lasers is
allowed for die experts only! So all the “lefthanders” stay away and do not disturben the brainstorming von here working
intelligencies. Otherwise you will be out thrown and kicked anderswhere! Also: please keep still and only watchen astaunished the blinkenlights.
anselm is offline   Reply With Quote
Old 03-21-2011, 05:13 PM #3
Benm's Avatar
Class 4 Laser
 
Join Date: Aug 2007
Location: Netherlands
Posts: 7,437
Rep Power: 18210
Benm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond repute
Benm Benm is online now
Class 4 Laser
Benm's Avatar
 
Join Date: Aug 2007
Location: Netherlands
Posts: 7,437
Rep Power: 18210
Benm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond repute
Default Re: Characteristics of Batteries vs. Wall Warts

The problem with some wallwarts is that their output voltage drops significantly with load, and that can sometimes create an unstable situation. If its a good quality one and the same voltage as the batteries will be, they're fine for testing purposes.

The best solution is to put a capacitor to ground on the input lead of the lm317. You can leave it in place when power it with batteries, but also remove it or replace it with a smaller one if space is limited.
Benm is online now   Reply With Quote
Reply





Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On











Loading








Green Laser Pointers by Category Blue Laser Pointers by Category Red Laser Pointers by Category
Yellow Laser Pointers by Category Violet Laser Pointers by Category Orange Laser Pointers by Category
Top Laser Pointers by Power - 1 Watt+ Top Laser Pointers by Power - 500mW+ Top Laser Pointers by Power - 250mW+
Laser Pointer Database High Power Laser Pointers Laser Pointer Diodes






Privacy Policy | Advertising Disclaimer | Terms of Use


 


All times are GMT. The time now is 07:23 PM.


Powered by: vBulletin
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO
Privacy Policy | Advertising Disclaimer | Terms of Use
Copyright (C) 2017 Laser Pointer Forums, LLC