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.

One laser store meets all your needs

 Laser Pointer Forums - Discuss Laser Pointers Direct-Drive 445 Host

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

07-27-2010, 10:00 PM #49
 Class 3R Laser Join Date: Dec 2008 Location: Dallas, TX Posts: 1,577 Rep Power: 128
LarryDFW
Class 3R Laser

Join Date: Dec 2008
Location: Dallas, TX
Posts: 1,577
Rep Power: 128
Re: Direct-Drive 445 Host

Aaron;

Your host and #18650 battery was shipped Wed. July 21st by 1st Class mail.

Thanks;

LarryDFW

Quote:
 Originally Posted by Extrion Larry, Thanks, I got it.

__________________
UV LED Lights F/S, 445nm, Blu-Rays, Red 1/2W, Green Focusables,
Link- Blu-Ray/445 Diode Test Current Levels for Long Life

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

07-28-2010, 07:37 AM #50
 Class 1M Laser Join Date: May 2010 Location: Bay Area, CA, USA Posts: 110 Rep Power: 18
rev0
Class 1M Laser

Join Date: May 2010
Location: Bay Area, CA, USA
Posts: 110
Rep Power: 18
Re: Direct-Drive 445 Host

Quote:
 Originally Posted by laser_freak Or you could use a couple resistors is parallel to get a lower resistance value. The equation for the overall resistance is Rtotal=1/(R1 + R2 + R3 + etc...) You can also use an online resistor calculator instead for the calculation such as this one.
Correction, for multiple resistors the equivalent resistance is:

1/Req = 1/R1 + 1/R2 + ...

Thus, Req = 1/(1/R1 + 1/R2 + ...)

Or for two resistors, Req = R1*R2 / (R1 + R2)

Personally, I use Excel for my formulas, and I've got a "calculator" for a DDL driver (and others), to find both the ideal resistance for a given current, and for the exact current from a provided resistance, or several resistors in parallel. Saves a load of time, I can figure out the right resistance based on parallel resistors I have on hand in a matter of minutes.

I've attached the sheet if anyone wants it.
Attached Files
 laser-calcs.zip (56.9 KB, 32 views)

07-28-2010, 09:24 PM #51
 Class 2M Laser Join Date: Jan 2008 Location: Maine, US Posts: 673 Rep Power: 31
laser_freak
Class 2M Laser

Join Date: Jan 2008
Location: Maine, US
Posts: 673
Rep Power: 31
Re: Direct-Drive 445 Host

Quote:
 Originally Posted by rev0 Correction, for multiple resistors the equivalent resistance is: 1/Req = 1/R1 + 1/R2 + ... Thus, Req = 1/(1/R1 + 1/R2 + ...) Or for two resistors, Req = R1*R2 / (R1 + R2) Personally, I use Excel for my formulas, and I've got a "calculator" for a DDL driver (and others), to find both the ideal resistance for a given current, and for the exact current from a provided resistance, or several resistors in parallel. Saves a load of time, I can figure out the right resistance based on parallel resistors I have on hand in a matter of minutes. I've attached the sheet if anyone wants it.
Oops. Yes yours is the correct equation. I updated my original reply to be correct.

07-29-2010, 08:50 AM #52
 Class 4 Laser Join Date: Sep 2007 Location: Northern CA, U.S. Astrophotography! (Some of my Photos) Posts: 9,851 Rep Power: 3922
jayrob
Class 4 Laser

Join Date: Sep 2007
Location: Northern CA, U.S. Astrophotography! (Some of my Photos)
Posts: 9,851
Rep Power: 3922
Re: Direct-Drive 445 Host

Quote:
 Originally Posted by Wallydraigle Can you expound on the direct drive thing, or link to somewhere that explains it? You're just connecting the laser diode directly to the battery and that's that?
With direct drive, it would be very simple to measure current to the diode by just measuring the battery current draw...

And of course, the corresponding power reading and what lens used would be helpful information...

But obviously, the diode output will drop significantly as the battery drains. Unlike a FlexDrive or Micro BoostDrive build...

Edit: I saw that the current and power output is mentioned in the first post... So at only 600mA's, that means that the voltage of the battery must be instantly dropping as the load is put on it. And that is why it is only giving 600mA's.

And obviously, as the battery drains, the power will continue to drop...
__________________
Personal lasers:
(just a few - too many to list) RPL 425, Sypder III Krypton, RPL 35 (473), GLP-473, GLP-593.5, HeNe 632.8,
Many DIY 445, red, blu-ray, green, 635, and 450 builds...

Looking for a DIY kit?

Take a look at some of my more popular kits linked in color...

* FS: 405-G-1 Glass Lens Mod for Blu-ray! 31% increase in power vs AixiZ acrylic!

* FS: New! 1000 Lumen XML-2 Maglite Modification With Voltage Monitor! - Parts or Complete Light! Must see!

* FS: Polished Stainless Steel Green Kit! Easy assembly in minutes!

* FS: Large Maglite Monster Kits! Side Button Forward Clicky! Custom Head Option! Gnarly...

Click here for a list of my build kits! Projects and tutorials too!

Last edited by jayrob; 07-29-2010 at 08:57 AM.

07-30-2010, 03:23 AM #53
 Class 3R Laser Join Date: Dec 2008 Location: Dallas, TX Posts: 1,577 Rep Power: 128
LarryDFW
Class 3R Laser

Join Date: Dec 2008
Location: Dallas, TX
Posts: 1,577
Rep Power: 128
Re: Direct-Drive 445 Host

Quote:
 Originally Posted by jayrob But obviously, the diode output will drop significantly as the battery drains. Unlike a FlexDrive or Micro BoostDrive build... I saw that the current and power output is mentioned in the first post... So at only 600mA's, that means that the voltage of the battery must be instantly dropping as the load is put on it. And that is why it is only giving 600mA's. And obviously, as the battery drains, the power will continue to drop...
The direct drive is possible because the voltage required by the diode matches up with the voltage of the battery (and the host has a good heatsink).

It draws 600ma because the voltage that the charged battery supplies equals the voltage required by the diode for that 600ma.

I checked the voltage drop over 10 minutes of continuous use.

It was only ~5% with the high energy 18650 batteries I am using.

That power difference is fine for my pointer usage.

Dr. Lava's Micro-Boost (with the new jumpers) is fine also.

LarryDFW
__________________
UV LED Lights F/S, 445nm, Blu-Rays, Red 1/2W, Green Focusables,
Link- Blu-Ray/445 Diode Test Current Levels for Long Life

Last edited by LarryDFW; 12-04-2011 at 03:24 AM.

08-01-2010, 01:05 AM #54
 Class 3B Laser Join Date: Nov 2007 Location: Napa, CA, USA Posts: 4,923 Rep Power: 326
yobresal
Class 3B Laser

Join Date: Nov 2007
Location: Napa, CA, USA
Posts: 4,923
Rep Power: 326
Re: Direct-Drive 445 Host

What about 2 10440 lithiums. Would that work direct drive or will it be too much voltage?
__________________
Looking for 445nm diodes? modules? drivers? lenses? Contact DTR!!!! He is the man.

08-01-2010, 02:47 AM #55
 Class 1M Laser Join Date: May 2010 Location: Bay Area, CA, USA Posts: 110 Rep Power: 18
rev0
Class 1M Laser

Join Date: May 2010
Location: Bay Area, CA, USA
Posts: 110
Rep Power: 18
Re: Direct-Drive 445 Host

Quote:
 Originally Posted by yobresal What about 2 10440 lithiums. Would that work direct drive or will it be too much voltage?
You can use them directly if they're both in parallel. If they're in series, the maximum voltage they'll put out should be 8.4V, so use the diode's forward voltage of about 4.2, and your resistor needs to drop 4.2V in that circuit. If you're driving at 500mA for example, your resistor should be: V = I * R => R = 4.2 / 0.500 = 8.4 Ohms. This is a pretty inefficient setup though, because the power the resistor dissipates is I^2 * R = 0.25 * 8.4 = 1.05W, or 4.2W if you are driving at 1A.

08-01-2010, 05:48 AM #56
 Class 3B Laser Join Date: Nov 2007 Location: Napa, CA, USA Posts: 4,923 Rep Power: 326
yobresal
Class 3B Laser

Join Date: Nov 2007
Location: Napa, CA, USA
Posts: 4,923
Rep Power: 326
Re: Direct-Drive 445 Host

Thanks Rev! I appreciate your informative response.
__________________
Looking for 445nm diodes? modules? drivers? lenses? Contact DTR!!!! He is the man.

11-21-2010, 07:47 AM #57
 Class 3R Laser Join Date: Dec 2008 Location: Dallas, TX Posts: 1,577 Rep Power: 128
LarryDFW
Class 3R Laser

Join Date: Dec 2008
Location: Dallas, TX
Posts: 1,577
Rep Power: 128
Re: Direct-Drive 445 Host

rev0;

A buck driver might be a better solution,
since you are trying to drop a lot of voltage (8.4 to 4.5VDC)

LarryDFW
__________________
UV LED Lights F/S, 445nm, Blu-Rays, Red 1/2W, Green Focusables,
Link- Blu-Ray/445 Diode Test Current Levels for Long Life

11-22-2010, 09:07 PM #58
 Class 1M Laser Join Date: Dec 2009 Location: Holly Springs N.C. Posts: 234 Rep Power: 9
More Power
Class 1M Laser

Join Date: Dec 2009
Location: Holly Springs N.C.
Posts: 234
Rep Power: 9
Re: Direct-Drive 445 Host

It's a shame the host is so expensive, its got a great heat sink I cant seem to find anywhere else, people like small slim builds to much.
__________________
200mw SLD1239-54 laser
4x5/10mw 635nm pointers
100mw techlasers
1,650mw DTR Guidesman (avatar)
500mw 12x broken

01-22-2011, 05:34 AM #59
 Class 3R Laser Join Date: Dec 2008 Location: Dallas, TX Posts: 1,577 Rep Power: 128
LarryDFW
Class 3R Laser

Join Date: Dec 2008
Location: Dallas, TX
Posts: 1,577
Rep Power: 128
Re: Direct-Drive 445 Host

More Power;

I have bought a large quantity of these hosts.

Send me a PM if you need one (\$45 with 18650 cell ).

The finned heat sink is required for high power and duty cycles.

LarryDFW
__________________
UV LED Lights F/S, 445nm, Blu-Rays, Red 1/2W, Green Focusables,
Link- Blu-Ray/445 Diode Test Current Levels for Long Life

03-04-2011, 11:18 AM #60
 Class 2 Laser Join Date: Apr 2009 Location: sausalito Posts: 435 Rep Power: 655
nkgamer1990
Class 2 Laser

Join Date: Apr 2009
Location: sausalito
Posts: 435
Rep Power: 655
Re: Direct-Drive 445 Host

\$45 for the host and heatsink plus an
18650 hicap battery?

question 2, i can connect an 18650 battery directly to a heatsinked a130 diode and safely power it up?
__________________
405nm dilda phr 100mw
405nm c6 12x 440mw
445nm a140 custom lab 1500mw
445nm a140 c6 1500mw
473nm bw tek lab 10mw
532nm needle beam 50mw
532nm olike 480mw
532nm lasever 960mw lab unit
638nm custom 700mw lab unit
650nm rifle 250mw
rgb projector 638nm 532nm 445nm

03-10-2011, 05:41 AM #61
 Class 3R Laser Join Date: Dec 2008 Location: Dallas, TX Posts: 1,577 Rep Power: 128
LarryDFW
Class 3R Laser

Join Date: Dec 2008
Location: Dallas, TX
Posts: 1,577
Rep Power: 128
Re: Direct-Drive 445 Host

Quote:
 Originally Posted by nkgamer1990 \$45 for the host and heatsink plus an 18650 hicap battery? question 2, i can connect an 18650 battery directly to a heatsinked a130 diode and safely power it up?
1. Yes for host and 18650 battery (without machined heatsink).

2. Yes, with diode in heatsink.

LarryDFW
__________________
UV LED Lights F/S, 445nm, Blu-Rays, Red 1/2W, Green Focusables,
Link- Blu-Ray/445 Diode Test Current Levels for Long Life

06-12-2011, 05:40 AM #62
 Class 3R Laser Join Date: Dec 2008 Location: Dallas, TX Posts: 1,577 Rep Power: 128
LarryDFW
Class 3R Laser

Join Date: Dec 2008
Location: Dallas, TX
Posts: 1,577
Rep Power: 128
Re: Direct-Drive 445 Host

Just received some new 2800mah lithium ion cells.

They are a safer technology design.

They are also higher voltage designs, with low internal resistance.

My direct drive 445nm is now delivering ~675mw.

LarryDFW
__________________
UV LED Lights F/S, 445nm, Blu-Rays, Red 1/2W, Green Focusables,
Link- Blu-Ray/445 Diode Test Current Levels for Long Life

Last edited by LarryDFW; 12-04-2011 at 03:18 AM.

12-04-2011, 03:17 AM #63
 Class 3R Laser Join Date: Dec 2008 Location: Dallas, TX Posts: 1,577 Rep Power: 128
LarryDFW
Class 3R Laser

Join Date: Dec 2008
Location: Dallas, TX
Posts: 1,577
Rep Power: 128
Re: Direct-Drive 445 Host

Just received some new 3000mah Samsung lithium ion cells.

They are a safer technology design.

They are also higher voltage designs (4.35VDC), with low internal resistance.

My direct drive 445nm is now delivering ~700mw.

LarryDFW
__________________
UV LED Lights F/S, 445nm, Blu-Rays, Red 1/2W, Green Focusables,
Link- Blu-Ray/445 Diode Test Current Levels for Long Life

Last edited by LarryDFW; 12-04-2011 at 03:25 AM.

02-24-2013, 06:27 PM #64
 Class 2 Laser Join Date: Nov 2007 Posts: 317 Rep Power: 11
xanatos
Class 2 Laser

Join Date: Nov 2007
Posts: 317
Rep Power: 11
Re: Direct-Drive 445 Host

Nice info on direct driving - if, like me, you don't really demand that the intensity stays at maximum until the batteries finally give up the ghost, it's apparently fine, especially if the Vb very nearly equals the Vf of the diode.

Thanks for the info!

Dave

 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 11:42 PM.

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