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 06-15-2014, 07:08 PM #1
Marco Polo's Avatar
Class 2M Laser
 
Join Date: Nov 2012
Location: Ohio, USA
Posts: 613
Rep Power: 625
Marco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond repute
Marco Polo Marco Polo is offline
Class 2M Laser
Marco Polo's Avatar
 
Join Date: Nov 2012
Location: Ohio, USA
Posts: 613
Rep Power: 625
Marco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond repute
Default Test load or high wattage resistor?

I saw it mentioned in another thread that you don't need a test load made of diodes and whatnot to test driver output. One of the people in the thread said that he just used a high-wattage resistor as the test load and claimed that he never had a problem with it.

The logic put forth was that the laser diode drops 100% of the voltage put to it, and that the driver is going to apply whatever voltage it needs to in order to deliver its set current through the load. With that in mind, a high-wattage resistance that will keep the driver within its safe voltage limits should function as a test load.

Can I then put the DMM in series with the circuit for a direct current measurement? Or will it introduce oscillations and/or otherwise give a bad reading?

Curious about it; I have a dead 650nm diode here from a Lazerer LZCS, looks like an LPC-826 or similar. The driver seems ok, it will light up the LED'd diode. I'm guessing it's some kind of buck driver, or maybe a linear... it has a transistor and an IC, a resistor, some caps. No coil. Would like to see what current it's set to and whether I could use it for something else. If I put 8.2 ohms across it the driver should be fine because unless it's a boost driver (red diode, so it's not) then max v-out 3.7 volts, which would be at most 451mA with an 8.2 ohm load. Right?

I just wanted to find out ahead of time if I can use a power resistor and be fine with that, or if I do need to put together a test load with diodes and the like. I would hate to try it later, on a driver that I do care about, and have it die. Thanks for any clarification on the matter!


__________________

808nm : SkyLaser HL808 820mW
650nm : [C6] LPC-826 215mW - SkyLaser HL650 175mW - Radio Shack <5mW
638nm : Opnext HL63603TG 190mW - AtlasNova <5mW
632nm : Metrologic ML-868 <5mW - Uniphase 155ASL-1 HeNe 0.95mW
543nm : Melles-Griot 05-LGR-193-497 HeNe 2.4mW
532nm : SkyLaser HL532 w/ IR filter 200mW - Fasttech SD-301 120mW - Lazerer LZCS 105mW - Laser 301 custom mod 85mW - various Laser 301's
520nm : [C6] Osram PL520 110mW - SkyLaser HL520 50mW
450nm : [C6] Osram PL450 260mW - Lazerer LZCS 145mW - SkyLaser HL450 95mW - SkyLaser LP450 90mW
405nm : Laser 303 85mW - Laser 301 90mW

Radiant X4 LPM from Illumination Supply


CHEAP BATTERIES CAN KILL YOU - please read this thread to see the truth about UltraFire and other CRAP brands!

Last edited by Marco Polo; 06-15-2014 at 07:11 PM.
Marco Polo is offline   Reply With Quote







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







Old 06-18-2014, 04:00 AM #2
Cyparagon's Avatar
Class 4 Laser
 
Join Date: Sep 2007
Location: Wisconsin
Posts: 9,141
Rep Power: 9321
Cyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond repute
Cyparagon Cyparagon is online now
Class 4 Laser
Cyparagon's Avatar
 
Join Date: Sep 2007
Location: Wisconsin
Posts: 9,141
Rep Power: 9321
Cyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond repute
Default Re: Test load or high wattage resistor?

A power resistor will work fine as a load. But the characteristics are linear, where a diode is exponential, so you need to change your resistor when you change the current or when you change the type of diode you want to simulate. I think it's easier to use diodes, myself.

DMM in ammeter mode acts as a very low inductance in series with a very low resistance. It will have no effect on the current regulation in the vast majority of cases, and will give you the average* current through it.

If there's no inductor, it's a linear driver. As such, it will be okay if you use only the DMM as the load. Don't have it active this way for too long though, since the IC may overheat if you're not paying attention.
__________________
A problem well stated is a problem half solved.
Cyparagon is online now   Reply With Quote
Old 06-22-2014, 02:24 AM #3
Benm's Avatar
Class 4 Laser
 
Join Date: Aug 2007
Location: Netherlands
Posts: 7,427
Rep Power: 15904
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: 7,427
Rep Power: 15904
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: Test load or high wattage resistor?

On an ideal driver it should not matter at all. That would output the same amount of current across a resistor, bank of diodes or a monkey wernch.

Test loads comprised of several silicon diodes and a bit of a resistance in series approximate the behaviour of real laser diodes best though, making them preferable for testing.

A multimeter on amperage range could be a poor choice since it has very low resistance in this configuration. A perfect driver would manage just fine, but don't epxect boost drivers to behave with a load like that.
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 05:38 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