Welcome to Laser Pointer Forums! If you are looking for a laser you may want to check out the Laser Company Top Sites List. The link will open in a new window for your convenience.

Colorful 2018, Colorful Laser Power Meter
 Laser Pointers Pondering Laser Efficiency

LPF Laser Pointer Company Database (link opens new window)

09-13-2012, 01:08 AM #1
 Junior Member Join Date: Aug 2012 Location: Ohio, USA Posts: 8 Rep Power: 0
TZ250
Junior Member

Join Date: Aug 2012
Location: Ohio, USA
Posts: 8
Rep Power: 0
Pondering Laser Efficiency

Everyone,
My new Survival Laser laser is a lot of fun. Soon, I will test the output and report the results here.

The expected output is 2W. So, I did some quick checking of the battery voltage and current. My two batteries measured 7.81V. The current measured 1.7A.

Since P=VI, Watts=7.81V X 1.7A = 13.277W.

Assuming a 2W output, the efficiency is 2W/13.277W = 15.06% efficiency.

I was hoping for 50% efficiency, but that is not going to happen.

Does the laser really loose that much energy due to heat and resistance (which is turned to heat)?

Am I missing something?
P.S. I searched for that information, but did not find the answer. I must have used the wrong search terms.

Last edited by TZ250; 09-13-2012 at 01:10 AM.

09-13-2012, 02:32 AM #2
 Class 4 Laser Join Date: Sep 2007 Location: Wisconsin Posts: 9,315 Rep Power: 385035
Cyparagon
Class 4 Laser

Join Date: Sep 2007
Location: Wisconsin
Posts: 9,315
Rep Power: 385035
Re: Pondering Laser Efficiency

That's the efficiency of the entire system - the "wall plug efficiency," although you're not accounting for cell charger or charge cycle losses.

You have heat lost in the cells, driver, diode, and optical assembly. Diode efficiency is much better. It's like 4.5V drop at 1.7A so 26% or so. Beefy IR diodes can be up to 60%.
__________________
A problem well stated is a problem half solved.

09-13-2012, 02:01 PM #3
 Class 3R Laser Join Date: Jul 2010 Location: Olomouc, Czech Republic Posts: 1,516 Rep Power: 153
DrSid
Class 3R Laser

Join Date: Jul 2010
Location: Olomouc, Czech Republic
Posts: 1,516
Rep Power: 153
Re: Pondering Laser Efficiency

Yep .. 445nm diodes 20%-30%. But the driver burns another 50%. If you want to be effective, discard the driver ! Check direct drive build in my sig. But then you are limited to what batteries you have at hand, and there are also other problems, like output stability.
__________________
200mw (35mw compared) FocalPrice cheap green AA - Review
500mw (estimated) 445nm Minimalistic Orange Emos Direct Drive. Thread
1500mw (estimated) 445nm Jayrob's Solarforce L2P. Review

Last edited by DrSid; 09-13-2012 at 02:02 PM.

09-13-2012, 02:13 PM #4
 Class 2M Laser Join Date: Jan 2012 Location: Croatia Posts: 745 Rep Power: 87377
Cel
Class 2M Laser

Join Date: Jan 2012
Location: Croatia
Posts: 745
Rep Power: 87377
Re: Pondering Laser Efficiency

15% is quite good. Just look at gas lasers...

09-13-2012, 04:09 PM #5
 Junior Member Join Date: Aug 2012 Location: Ohio, USA Posts: 8 Rep Power: 0
TZ250
Junior Member

Join Date: Aug 2012
Location: Ohio, USA
Posts: 8
Rep Power: 0
Re: Pondering Laser Efficiency

Quote:
 Originally Posted by Cyparagon That's the efficiency of the entire system - the "wall plug efficiency," although you're not accounting for cell charger or charge cycle losses.
Cyparagon, you are correct. It is daunting to think of trying to calculate total efficiency. We would have to include the efficiencies of the power plant, the losses in the lines, the efficiency of the coal transportation system....

That is a long way to say, that I am only interested in the "wall plug efficiency".

Quote:
 Originally Posted by DrSid Yep .. 445nm diodes 20%-30%. But the driver burns another 50%. If you want to be effective, discard the driver ! Check direct drive build in my sig. But then you are limited to what batteries you have at hand, and there are also other problems, like output stability.
Thanks for the information. I'm a newbie to laser construction, so I'll stay with a driver for a while. I did not expect the driver to be so inefficient.

Quote:
 Originally Posted by Cel 15% is quite good. Just look at gas lasers...
Thank you. I will research gas lasers. Prior to this experiment, I could not imagine calling 15% efficiency 'good'.

09-13-2012, 04:13 PM #6
 Class 4 Laser Join Date: Dec 2007 Location: Belgium Posts: 5,368 Rep Power: 3118
Blord
Class 4 Laser

Join Date: Dec 2007
Location: Belgium
Posts: 5,368
Rep Power: 3118
Re: Pondering Laser Efficiency

Did you measured the battery voltage under load ? It could sag a lot under 1.7Amps.
__________________
405nm 400mW S06J C6
445nm 3W Big Boy, 2.8W Dominator, 2.4W Steel Laser
450nm 240mW PL450 C6
473nm 100mW PGL-III-C-473
520nm 55mW Skylaser PL520
532nm 821mW Skylaser PL532, 133mW Jetlasers Ti-B
589nm 100mW PGL-III-C-589
635nm 70mW Sanyo SenTorch
638nm 175mW Ehgemus, 1W Rook
660nm 1216mW Skylaser PL660, 263mW LPC826 C6
685nm 33mW Fujitsu FLD6A2TK C6
780nm 150mW Dilda
808nm 640mW C6

I have copper 501B and Dominator lasers for sale !

09-13-2012, 05:18 PM #7
 Class 4 Laser Join Date: Sep 2007 Location: Wisconsin Posts: 9,315 Rep Power: 385035
Cyparagon
Class 4 Laser

Join Date: Sep 2007
Location: Wisconsin
Posts: 9,315
Rep Power: 385035
Re: Pondering Laser Efficiency

If you see the cells sag to 6V for example, you can't take that new value as the supply voltage (unless you're just calculating driver efficiency). The other 1.8V is dropped in the cell itself because of a parasitic series resistance inside the cell. Therefore, the voltage sagging is actually another source of heat and subsequent inefficiency.
__________________
A problem well stated is a problem half solved.

09-13-2012, 05:24 PM #8
 Class 3B Laser Join Date: Dec 2009 Posts: 3,175 Rep Power: 3651
BShanahan14rulz
Class 3B Laser

Join Date: Dec 2009
Posts: 3,175
Rep Power: 3651
Re: Pondering Laser Efficiency

Quote:
 Originally Posted by TZ250 Prior to this experiment, I could not imagine calling 15% efficiency 'good'.
ex: 5W out, 7000W in. .07% efficiency guesstimate.

09-13-2012, 08:27 PM #9
 Junior Member Join Date: Aug 2012 Location: Ohio, USA Posts: 8 Rep Power: 0
TZ250
Junior Member

Join Date: Aug 2012
Location: Ohio, USA
Posts: 8
Rep Power: 0
Re: Pondering Laser Efficiency

Thank you all for helping me to better understand the losses in this system. I did not measure battery voltage under load.

09-13-2012, 09:12 PM #10
 Class 4 Laser Join Date: Sep 2007 Location: Wisconsin Posts: 9,315 Rep Power: 385035
Cyparagon
Class 4 Laser

Join Date: Sep 2007
Location: Wisconsin
Posts: 9,315
Rep Power: 385035
Re: Pondering Laser Efficiency

lawl small frame ion lasers. 1kW in, 40mW out. ~0.004% efficient.
__________________
A problem well stated is a problem half solved.

09-13-2012, 10:12 PM #11
 Junior Member Join Date: Sep 2012 Location: Two hours past Infinite Posts: 21 Rep Power: 0
Gigas
Junior Member

Join Date: Sep 2012
Location: Two hours past Infinite
Posts: 21
Rep Power: 0
Re: Pondering Laser Efficiency

Quote:
 Originally Posted by Cyparagon lawl small frame ion lasers. 1kW in, 40mW out. ~0.004% efficient.
Jesus! That's ridiculous!

I knew lasers were inefficient but wow!
__________________
SOON TO BE 445 nm RIFLE 1W focusable laser

Stuck in Michigan. US.

09-15-2012, 04:32 PM #12
 Class 3R Laser Join Date: Aug 2010 Location: Southwest Utah Posts: 1,452 Rep Power: 113974
Garoq
Class 3R Laser

Join Date: Aug 2010
Location: Southwest Utah
Posts: 1,452
Rep Power: 113974
Re: Pondering Laser Efficiency

Did you measure current draw at the tailcap? It should be closer to 1.37-1.40A.
__________________
Serving thousands of satisfied customers since 2010!

Survival Laser, Inc., 2113 W 850 N, Cedar City, UT 84721

Eagle Pair® Laser Safety Goggles • AW™ Batteries • C6/S4/Stainless/S4X Hosts • Custom Diode Drivers • Chargers • Lenses • Accessories

LPF member 10% everyday discount code = LPF445
Free shipping on US orders over \$100 net
Free shipping on international orders over \$200 net

AND THIS: Instructive Video Review on Goggles Safety

7 Watt S4X Host/NUBM44 Diode/SXD Tutorial
C6 Laser Assembly Tutorial
How to Install a Blank Battery Contact Board Into a Drilled Pill
How to Solder a DTR Diode Module to a Survival Laser Driver & Pill Assembly
Installing and Testing the SL-SD-1/DX 26110 Driver in a C6 Pill

09-15-2012, 04:41 PM #13
 Junior Member Join Date: Aug 2012 Location: Ohio, USA Posts: 8 Rep Power: 0
TZ250
Junior Member

Join Date: Aug 2012
Location: Ohio, USA
Posts: 8
Rep Power: 0
Re: Pondering Laser Efficiency

Quote:
 Originally Posted by Garoq Did you measure current draw at the tailcap? It should be closer to 1.37-1.40A.
Gary, I removed the tailcap and connected one probe to the battery and the other to the host.

I hope to go to the optics lab next week. I will report the results.
__________________
Rob
http://tinyurl.com/8z4jn4d

09-15-2012, 05:43 PM #14
 Class 3R Laser Join Date: Aug 2010 Location: Southwest Utah Posts: 1,452 Rep Power: 113974
Garoq
Class 3R Laser

Join Date: Aug 2010
Location: Southwest Utah
Posts: 1,452
Rep Power: 113974
Re: Pondering Laser Efficiency

Quote:
 Originally Posted by TZ250 Gary, I removed the tailcap and connected one probe to the battery and the other to the host. I hope to go to the optics lab next week. I will report the results.
I should say that I usually measure 1.4A at 8.4V, so your number isn't that different.
__________________
Serving thousands of satisfied customers since 2010!

Survival Laser, Inc., 2113 W 850 N, Cedar City, UT 84721

Eagle Pair® Laser Safety Goggles • AW™ Batteries • C6/S4/Stainless/S4X Hosts • Custom Diode Drivers • Chargers • Lenses • Accessories

LPF member 10% everyday discount code = LPF445
Free shipping on US orders over \$100 net
Free shipping on international orders over \$200 net

AND THIS: Instructive Video Review on Goggles Safety

7 Watt S4X Host/NUBM44 Diode/SXD Tutorial
C6 Laser Assembly Tutorial
How to Install a Blank Battery Contact Board Into a Drilled Pill
How to Solder a DTR Diode Module to a Survival Laser Driver & Pill Assembly
Installing and Testing the SL-SD-1/DX 26110 Driver in a C6 Pill

 Thread Tools Display Modes Linear Mode

 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 OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

All times are GMT. The time now is 05:47 PM.

 -- DarkShadows V5 -- Responsive LPF -2562016 -- Default Style Contact Us - Laser Pointers - Archive - Top