Old 05-15-2018, 03:47 AM #1
Junior Member
 
Join Date: May 2018
Posts: 9
Rep Power: 0
electrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond repute
electrophile electrophile is offline
Junior Member
 
Join Date: May 2018
Posts: 9
Rep Power: 0
electrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond repute
Default 4A Laser Driver

I'm fairly new to lasers but an old hand at electronics. I started working with lasers about 2 years ago and since then I've been hooked! I came up with this 4A laser driver recently and the one shown here is a prototype that I use with my laser engraver that is powered by a 3.5W NUBM06 laser. A 10A driver prototype is also in the works. If this is something you folks would be interested in, I can start making more.

Here are the specs:
  1. 4A max current out at 5.5V
  2. Max VIN is 75V (recommended Max VIN is 60V)
  3. Two modes of current adjustment - PWM and potentiometer. Suggested method is to set the max current limit using the pot and then use to the PWM to vary power output. PWM frequency can be between 400Hz to about 100KHz.
  4. Soft start of about 5ms.
  5. Cycle by cycle current limit with low-power and thermal shutdown
  6. 500KHz switching frequency
  7. Terminal tabs on the board to attach external current meters for continuous current readout.
  8. JST VH connectors for input and output rated at 10A.




Last edited by electrophile; 05-15-2018 at 05:00 AM.
electrophile is offline   Reply With Quote


















Old 05-15-2018, 04:32 AM #2
Alaskan's Avatar
Super Moderator
 
Join Date: Jan 2014
Location: Dohaha, Qatar
Posts: 10,921
Rep Power: 19691555
Alaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond repute
Alaskan Alaskan is offline
Super Moderator
Alaskan's Avatar
 
Join Date: Jan 2014
Location: Dohaha, Qatar
Posts: 10,921
Rep Power: 19691555
Alaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond repute
Default Re: 4A Laser Driver

Nice, I might be interested in a 10A version, not many of those available yet. What would the maximum input voltage be for it?

Please post an introduction in the welcome section, a general geo location is also welcome. I guess your last post is an introduction too, but members like to see more, if you are willing to share more. I started in electronics in high school back in the early 70's, but lasers are fairly new to me too, just a few years since I started this as my new hobby, used to be Ham radio and flying private aircraft.
__________________

Attention new brothers of the collimated light!

Newbie advice: Please take the time to first make an introduction in the Welcome section before posting questions: - https://laserpointerforums.com/f37


Divergence to spot size calc: - 1 mRad is about .057 degrees which expands to be ~very~ roughly ~10% the diameter of the moon or sun at their distances.

Divergence Calculator: pseudonomen137's JScript mRad Calculator - Measure your lasers beam dia. at 1 foot & then 20'.

Online calc. to determine spot intensity at different mRad's & powers: http://tinyurl.com/divergence-calculator

Laser Power Density Calculator: Laser Power Density Calculator - Ophir

Build a beam expander to reduce divergence: http://tinyurl.com/BeamExpander

University YAG Project The Professor's Homebuilt Lasers Site - YAG Lasers

YAG Power Calc. Laser Peak Power Calculator - Ophir

Angular Size Calculator; use with diode angle of radiation spec. for lens dia. at FL: Angular Size Calculator

RHD's Relative Brightness vs Wavelength Calc: https://tinyurl.com/RHD-brightness

High Current Pulse Diode Drivers: https://tinyurl.com/ya7whuk3

Last edited by Alaskan; 05-15-2018 at 04:39 AM.
Alaskan is offline   Reply With Quote
Old 05-15-2018, 04:36 AM #3
RedCowboy's Avatar
Class 4 Laser
 
Join Date: Jul 2015
Location: Suburbs of Atlanta Georgia
Posts: 6,380
Rep Power: 18277169
RedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond repute
RedCowboy RedCowboy is online now
Class 4 Laser
RedCowboy's Avatar
 
Join Date: Jul 2015
Location: Suburbs of Atlanta Georgia
Posts: 6,380
Rep Power: 18277169
RedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond repute
Default Re: 4A Laser Driver

An output of 10a @ 5v is something I could make use of, do you have these for sale, ebay perhaps ?

p.s. Yes do post a simple introduction in the welcome thread here >>> https://laserpointerforums.com/f37/
__________________
You can not put freedom in a bag.
You can't weigh it on a scale or offer it for sale.
Yet it is the single most valuable thing anyone has ever had.

Last edited by RedCowboy; 05-15-2018 at 05:02 AM.
RedCowboy is online now   Reply With Quote
Old 05-15-2018, 04:52 AM #4
Junior Member
 
Join Date: May 2018
Posts: 9
Rep Power: 0
electrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond repute
electrophile electrophile is offline
Junior Member
 
Join Date: May 2018
Posts: 9
Rep Power: 0
electrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond repute
Default Re: 4A Laser Driver

Quote:
Originally Posted by Alaskan View Post
used to be Ham radio and flying private aircraft.
Learning to fly has been on my bucket list for a while now but its just so expensive :| Someday perhaps... I've posted an introduction just now.

Quote:
Originally Posted by Alaskan View Post
Nice, I might be interested in a 10A version, not many of those available yet. What would the maximum input voltage be for it?
Max VIN is 75V but realistically I'd recommend not to go higher than 60V.
electrophile is offline   Reply With Quote
Old 05-15-2018, 04:54 AM #5
Junior Member
 
Join Date: May 2018
Posts: 9
Rep Power: 0
electrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond repute
electrophile electrophile is offline
Junior Member
 
Join Date: May 2018
Posts: 9
Rep Power: 0
electrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond repute
Default Re: 4A Laser Driver

Quote:
Originally Posted by RedCowboy View Post
An output of 10a @ 5v is something I could make use, do you have these for sale, ebay perhaps ?

p.s. Yes do post a simple introduction in the welcome thread here >>> https://laserpointerforums.com/f37/
Just posted an introduction!

The 10A driver is not yet in production. Still testing it. I'll be sure to post my results once I get a production ready version and a subsequent purchase link too.
electrophile is offline   Reply With Quote
Old 05-15-2018, 04:55 AM #6
Alaskan's Avatar
Super Moderator
 
Join Date: Jan 2014
Location: Dohaha, Qatar
Posts: 10,921
Rep Power: 19691555
Alaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond repute
Alaskan Alaskan is offline
Super Moderator
Alaskan's Avatar
 
Join Date: Jan 2014
Location: Dohaha, Qatar
Posts: 10,921
Rep Power: 19691555
Alaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond repute
Default Re: 4A Laser Driver

That's great, I have a problem finding drivers which allow me to put a high enough VIN to allow stringing several laser diodes in series. What is the drop out voltage?
__________________

Attention new brothers of the collimated light!

Newbie advice: Please take the time to first make an introduction in the Welcome section before posting questions: - https://laserpointerforums.com/f37


Divergence to spot size calc: - 1 mRad is about .057 degrees which expands to be ~very~ roughly ~10% the diameter of the moon or sun at their distances.

Divergence Calculator: pseudonomen137's JScript mRad Calculator - Measure your lasers beam dia. at 1 foot & then 20'.

Online calc. to determine spot intensity at different mRad's & powers: http://tinyurl.com/divergence-calculator

Laser Power Density Calculator: Laser Power Density Calculator - Ophir

Build a beam expander to reduce divergence: http://tinyurl.com/BeamExpander

University YAG Project The Professor's Homebuilt Lasers Site - YAG Lasers

YAG Power Calc. Laser Peak Power Calculator - Ophir

Angular Size Calculator; use with diode angle of radiation spec. for lens dia. at FL: Angular Size Calculator

RHD's Relative Brightness vs Wavelength Calc: https://tinyurl.com/RHD-brightness

High Current Pulse Diode Drivers: https://tinyurl.com/ya7whuk3
Alaskan is offline   Reply With Quote
Old 05-15-2018, 04:59 AM #7
Junior Member
 
Join Date: May 2018
Posts: 9
Rep Power: 0
electrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond repute
electrophile electrophile is offline
Junior Member
 
Join Date: May 2018
Posts: 9
Rep Power: 0
electrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond repute
Default Re: 4A Laser Driver

I haven't tested these with LDOs in series. Do you mean the voltage drop when operating at full load? At the full rated 4A, the voltage across the single LDO was about 5.2V. The output voltage can be adjusted to be higher though. I'd just have to use a different combination of certain components which wouldn't be too big a deal.

Last edited by electrophile; 05-15-2018 at 05:04 AM.
electrophile is offline   Reply With Quote
Old 05-15-2018, 05:01 AM #8
Alaskan's Avatar
Super Moderator
 
Join Date: Jan 2014
Location: Dohaha, Qatar
Posts: 10,921
Rep Power: 19691555
Alaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond repute
Alaskan Alaskan is offline
Super Moderator
Alaskan's Avatar
 
Join Date: Jan 2014
Location: Dohaha, Qatar
Posts: 10,921
Rep Power: 19691555
Alaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond repute
Default Re: 4A Laser Driver

I just meant how much voltage is lost from the VIN to the Out, in other words, if supplying 8.2 VDC, what is the maximum output voltage at the rated full current the device can produce?
__________________

Attention new brothers of the collimated light!

Newbie advice: Please take the time to first make an introduction in the Welcome section before posting questions: - https://laserpointerforums.com/f37


Divergence to spot size calc: - 1 mRad is about .057 degrees which expands to be ~very~ roughly ~10% the diameter of the moon or sun at their distances.

Divergence Calculator: pseudonomen137's JScript mRad Calculator - Measure your lasers beam dia. at 1 foot & then 20'.

Online calc. to determine spot intensity at different mRad's & powers: http://tinyurl.com/divergence-calculator

Laser Power Density Calculator: Laser Power Density Calculator - Ophir

Build a beam expander to reduce divergence: http://tinyurl.com/BeamExpander

University YAG Project The Professor's Homebuilt Lasers Site - YAG Lasers

YAG Power Calc. Laser Peak Power Calculator - Ophir

Angular Size Calculator; use with diode angle of radiation spec. for lens dia. at FL: Angular Size Calculator

RHD's Relative Brightness vs Wavelength Calc: https://tinyurl.com/RHD-brightness

High Current Pulse Diode Drivers: https://tinyurl.com/ya7whuk3
Alaskan is offline   Reply With Quote
Old 05-15-2018, 05:08 AM #9
paul1598419's Avatar
Class 4 Laser
 
Join Date: Sep 2013
Location: Washington State
Posts: 11,695
Rep Power: 19381877
paul1598419 has a reputation beyond reputepaul1598419 has a reputation beyond reputepaul1598419 has a reputation beyond reputepaul1598419 has a reputation beyond reputepaul1598419 has a reputation beyond reputepaul1598419 has a reputation beyond reputepaul1598419 has a reputation beyond reputepaul1598419 has a reputation beyond reputepaul1598419 has a reputation beyond reputepaul1598419 has a reputation beyond reputepaul1598419 has a reputation beyond repute
paul1598419 paul1598419 is online now
Class 4 Laser
paul1598419's Avatar
 
Join Date: Sep 2013
Location: Washington State
Posts: 11,695
Rep Power: 19381877
paul1598419 has a reputation beyond reputepaul1598419 has a reputation beyond reputepaul1598419 has a reputation beyond reputepaul1598419 has a reputation beyond reputepaul1598419 has a reputation beyond reputepaul1598419 has a reputation beyond reputepaul1598419 has a reputation beyond reputepaul1598419 has a reputation beyond reputepaul1598419 has a reputation beyond reputepaul1598419 has a reputation beyond reputepaul1598419 has a reputation beyond repute
Default Re: 4A Laser Driver

As you should know, the Vf of a laser diode depends on the current your driver allows it to draw. To string laser diodes in series is the easiest way to hold all their currents to a single value, regardless of the voltage drop across each one. That is why people are interested in the limit of its forward voltage.

It might be easier to let us know the topology of the driver. Is it linear, bucking, sepic.....
__________________
405nm Laser Pointer 45mW
405nm C11 700mW
405nm Laser Shack Pointer 80mW
Thor H Dual Power 445nm, 438 mW & 1648 mW
445nm 3 watts MS-SSW-II
445nm 2.2 watts Nichia MS Envy

473nm 50 mW BWB-10-OEM DPSS
477nm 127 mW 501B
488nm 135 mW EDC Sharp diode
488nm Uniphase #2201-20SLAT argon laser head and power supply >40mW
493nm 120 mW 501B
502nm 110 mW 501B Lifetime
520nm LaserLands pointer Measures 510nm
532nm LSR532H-1W Laser, LSR-PS-N1 Driver, RS-75-5 P.S. 1300 mW
532nm 200mW Thermostatically Controlled Fan Cooled (Besram) >230mW
532nm 189mW pocket lab laser
532nm lasers X6 100mW-200mW
532nm lasers X4 75mW- 140mW
574nm OptLaser DPSS Laser 36 mW
632.8nm P210 New Laser Tube 0.57mW Melles Griot 05-LMP-827-037 PS
632.8nm Spectra- Physics He- Ne #102-2 4mW heads X2 and #236 power supply
632.8nm PMS He-Ne # 201P/ LPS-115 2mW
632.8nm Siemens HeNe LGK7630S 7.6mW
638nm 1 watt Cyprus II
635nm 100mW pointer
650nm 65mW pointer
650nm 380mW 501B
808nm 1+W infrared laser
Ocean Optics USB2000 Spectrometer
B&W TEK BTC100 Spectrometers X3
Scientech Vector S310 with AC2500 10 Watt LPM/ Hyperion 6 Watt & 20 Watt LPM/ Radiant X4 3.7 Watt LPM

Last edited by paul1598419; 05-15-2018 at 05:11 AM.
paul1598419 is online now   Reply With Quote
Old 05-15-2018, 05:14 AM #10
RedCowboy's Avatar
Class 4 Laser
 
Join Date: Jul 2015
Location: Suburbs of Atlanta Georgia
Posts: 6,380
Rep Power: 18277169
RedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond repute
RedCowboy RedCowboy is online now
Class 4 Laser
RedCowboy's Avatar
 
Join Date: Jul 2015
Location: Suburbs of Atlanta Georgia
Posts: 6,380
Rep Power: 18277169
RedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond repute
Default Re: 4A Laser Driver

Also many of our favorite LD's live around 4.5a @ 4.5v but I am interested in 10a @ 4.7v and can supply DC in from 12v to 36v within my device size.
__________________
You can not put freedom in a bag.
You can't weigh it on a scale or offer it for sale.
Yet it is the single most valuable thing anyone has ever had.
RedCowboy is online now   Reply With Quote
Old 05-15-2018, 06:08 AM #11
Junior Member
 
Join Date: May 2018
Posts: 9
Rep Power: 0
electrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond repute
electrophile electrophile is offline
Junior Member
 
Join Date: May 2018
Posts: 9
Rep Power: 0
electrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond repute
Default Re: 4A Laser Driver

Quote:
Originally Posted by paul1598419 View Post
As you should know, the Vf of a laser diode depends on the current your driver allows it to draw. To string laser diodes in series is the easiest way to hold all their currents to a single value, regardless of the voltage drop across each one. That is why people are interested in the limit of its forward voltage.

It might be easier to let us know the topology of the driver. Is it linear, bucking, sepic.....
Ah I see. Its a buck driver with an external FET. I guess if you are going to string LDOs in series then the driver will have to be modified to account for the drop across each LDO. In which case, the output voltage will change from the design value of 5.5V to whatever is needed for the # of LDOs in series.
electrophile is offline   Reply With Quote
Old 05-15-2018, 06:10 AM #12
Junior Member
 
Join Date: May 2018
Posts: 9
Rep Power: 0
electrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond repute
electrophile electrophile is offline
Junior Member
 
Join Date: May 2018
Posts: 9
Rep Power: 0
electrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond repute
Default Re: 4A Laser Driver

Quote:
Originally Posted by RedCowboy View Post
Also many of our favorite LD's live around 4.5a @ 4.5v but I am interested in 10a @ 4.7v and can supply DC in from 12v to 36v within my device size.
Got it. Yes the max VIN is about 75V so it should be ok to drive it with those supplies.
electrophile is offline   Reply With Quote
Old 05-15-2018, 06:58 AM #13
Alaskan's Avatar
Super Moderator
 
Join Date: Jan 2014
Location: Dohaha, Qatar
Posts: 10,921
Rep Power: 19691555
Alaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond repute
Alaskan Alaskan is offline
Super Moderator
Alaskan's Avatar
 
Join Date: Jan 2014
Location: Dohaha, Qatar
Posts: 10,921
Rep Power: 19691555
Alaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond repute
Default Re: 4A Laser Driver

A high VIN sure allows a string of diodes in series, but how much voltage VIN is required to produce, for example, 5 volts out at a constant current value if using batteries with a much lower voltage? The difference is considered the drop-out voltage loss through the driver.
__________________

Attention new brothers of the collimated light!

Newbie advice: Please take the time to first make an introduction in the Welcome section before posting questions: - https://laserpointerforums.com/f37


Divergence to spot size calc: - 1 mRad is about .057 degrees which expands to be ~very~ roughly ~10% the diameter of the moon or sun at their distances.

Divergence Calculator: pseudonomen137's JScript mRad Calculator - Measure your lasers beam dia. at 1 foot & then 20'.

Online calc. to determine spot intensity at different mRad's & powers: http://tinyurl.com/divergence-calculator

Laser Power Density Calculator: Laser Power Density Calculator - Ophir

Build a beam expander to reduce divergence: http://tinyurl.com/BeamExpander

University YAG Project The Professor's Homebuilt Lasers Site - YAG Lasers

YAG Power Calc. Laser Peak Power Calculator - Ophir

Angular Size Calculator; use with diode angle of radiation spec. for lens dia. at FL: Angular Size Calculator

RHD's Relative Brightness vs Wavelength Calc: https://tinyurl.com/RHD-brightness

High Current Pulse Diode Drivers: https://tinyurl.com/ya7whuk3
Alaskan is offline   Reply With Quote
Old 05-15-2018, 10:00 AM #14
Junior Member
 
Join Date: May 2018
Posts: 9
Rep Power: 0
electrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond repute
electrophile electrophile is offline
Junior Member
 
Join Date: May 2018
Posts: 9
Rep Power: 0
electrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond reputeelectrophile has a reputation beyond repute
Default Re: 4A Laser Driver

Since this is a buck driver the input voltage has to be higher than the output. Theoretically it can still operate if the output voltage becomes equal to the input voltage. Thereafter the output voltage is directly proportional to the input voltage. The output current however is at the peak value the driver was designed for since the FET is ON all the time. To be on the safe side, the input voltage should be at least 2V above the needed output voltage. I've operated the above design from a 9V battery and it works great. If you are using 3.7V LiIon cells then you may want to have a 3S-xP combination for a 5V output.

Last edited by electrophile; 05-15-2018 at 10:01 AM.
electrophile is offline   Reply With Quote
Old 05-15-2018, 10:28 AM #15
Alaskan's Avatar
Super Moderator
 
Join Date: Jan 2014
Location: Dohaha, Qatar
Posts: 10,921
Rep Power: 19691555
Alaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond repute
Alaskan Alaskan is offline
Super Moderator
Alaskan's Avatar
 
Join Date: Jan 2014
Location: Dohaha, Qatar
Posts: 10,921
Rep Power: 19691555
Alaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond repute
Default Re: 4A Laser Driver

Thank you, that's the number I was looking for, 2 volts input above needed output voltage.
__________________

Attention new brothers of the collimated light!

Newbie advice: Please take the time to first make an introduction in the Welcome section before posting questions: - https://laserpointerforums.com/f37


Divergence to spot size calc: - 1 mRad is about .057 degrees which expands to be ~very~ roughly ~10% the diameter of the moon or sun at their distances.

Divergence Calculator: pseudonomen137's JScript mRad Calculator - Measure your lasers beam dia. at 1 foot & then 20'.

Online calc. to determine spot intensity at different mRad's & powers: http://tinyurl.com/divergence-calculator

Laser Power Density Calculator: Laser Power Density Calculator - Ophir

Build a beam expander to reduce divergence: http://tinyurl.com/BeamExpander

University YAG Project The Professor's Homebuilt Lasers Site - YAG Lasers

YAG Power Calc. Laser Peak Power Calculator - Ophir

Angular Size Calculator; use with diode angle of radiation spec. for lens dia. at FL: Angular Size Calculator

RHD's Relative Brightness vs Wavelength Calc: https://tinyurl.com/RHD-brightness

High Current Pulse Diode Drivers: https://tinyurl.com/ya7whuk3
Alaskan is offline   Reply With Quote
Old 05-15-2018, 08:46 PM #16
RedCowboy's Avatar
Class 4 Laser
 
Join Date: Jul 2015
Location: Suburbs of Atlanta Georgia
Posts: 6,380
Rep Power: 18277169
RedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond repute
RedCowboy RedCowboy is online now
Class 4 Laser
RedCowboy's Avatar
 
Join Date: Jul 2015
Location: Suburbs of Atlanta Georgia
Posts: 6,380
Rep Power: 18277169
RedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond reputeRedCowboy has a reputation beyond repute
Default Re: 4A Laser Driver

That's why I like to run 3 li cells in my builds, the SXD needs 6.8vin at minimum under load IINM and running 2 cells means more frequent charging, a lot of videos I watch I suspect the operator is not getting full power due to running 2 poor quality cells and sag below minimum vin, also I use IMR/INR formulated cells with low sag, but I have seen people driving nubm's with two ultrafire cells and I know they are not getting full power.
__________________
You can not put freedom in a bag.
You can't weigh it on a scale or offer it for sale.
Yet it is the single most valuable thing anyone has ever had.

Last edited by RedCowboy; 05-15-2018 at 08:48 PM.
RedCowboy is online now   Reply With Quote
Reply

Tags
driver, laser driver, pwm, soft start





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



























Privacy Policy | Advertising Disclaimer | Terms of Use


 


All times are GMT. The time now is 04:38 AM.


Powered by: vBulletin
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO
Privacy Policy | Advertising Disclaimer | Terms of Use
Copyright (C) 2017 Laser Pointer Forums, LLC