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help with cheap china laser 5.5W

Posted by baloo 
help with cheap china laser 5.5W
March 09, 2018 05:27AM
A month ago I got a cheap china laser engraver see [www.ebay.com.au]
It had no instruction on how to build it ,but I had built one before (300mw laser), the problem is that the control board get very hot and the solder melts. so I believe its the wrong control board for the 5.5w laser.
I would like to use an Ardunio uno and cnc v3.0 shield, but need to drive the 5.5w laser form it.
Can anyone help on how to do it ?
VDX
Re: help with cheap china laser 5.5W
March 09, 2018 05:41AM
... first -- the "5.5W" is the driving "power" of the diode, not the optical output energy!

Quote
from the transaction:
Support Power: 100mw-5500mw
...
Power supply:5.5W

- so get the info from the vendor about diode type and the "max. safe working" current - not the "max. rated"!

Then -- get a proper current driver for this diode

... and last, read through all the hundreds of threads with similar questions or hints for proper driving laser diodes ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
Re: help with cheap china laser 5.5W
March 09, 2018 06:38AM
.". first -- the "5.5W" is the driving "power" of the diode, not the optical output energy! "
I took the fan of the top of the Laser to see what voltage is , its 12v, it get its power from the same terminals as the laser board.

so at 12v 5.5w i should only be drawing P/ V = A .. 5.5w / 12v = 0.458 amps ?

Edited 2 time(s). Last edit at 03/09/2018 06:46AM by baloo.
VDX
Re: help with cheap china laser 5.5W
March 09, 2018 09:39AM
... no! - there is a constant current chip in the driver or inside of the diode cooler housing.

With "5.5W" power this could be a 2W-diode, which is specified with 1.5A at 3.7V, what multiplicated gives 1.5 x 3.7 = 5.55W! ... the remaining voltage from the operating point (here 12V - 3.7V = 8.3V) will be transferred into heat -- 1.5A x 8.3V => 12.45 Watt excessive heat ... this can easily melt your electronics!!!

The types variants are between 3.7V to 5V, so the current (and optical output) could be lower, or a different diode type ... get the essential infos ... or try your luck ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
Re: help with cheap china laser 5.5W
March 09, 2018 01:25PM
Thanks Viktor

I have been trying to contact the vendor for a month now, they do not answer me, so I'm flying blind here.
I'm not any good at electronice, (i'm a retiered shipwright ) smiling smiley
The only info I have is

Working Voltage DC 12V
Laser Module
Power supply:5.5W
Wave Length:450nm

my option is to use a large Mosfet to handle the current and heat ??

Edited 2 time(s). Last edit at 03/09/2018 02:10PM by baloo.
VDX
Re: help with cheap china laser 5.5W
March 09, 2018 03:52PM
... you can open the diode housing and scrap out all the silicone - could be, the constant current chip is "embedded" inside.

Remove it, solder two wires to the diode and search a new driver with proper documentation ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
Re: help with cheap china laser 5.5W
March 09, 2018 05:07PM
see attachments that is all I can see
in photo 1 the red black green an blue are the 12v in, the blue and green go starte to the fan.
in photo 2 the resd and yellow go start to the diode

Edited 2 time(s). Last edit at 03/09/2018 05:15PM by baloo.
Attachments:
open | download - WIN_20180310_07_53_36_Pro.jpg (488.8 KB)
open | download - WIN_20180310_07_53_50_Pro.jpg (505.1 KB)
open | download - WIN_20180310_08_01_35_Pro.jpg (393.9 KB)
VDX
Re: help with cheap china laser 5.5W
March 09, 2018 05:42PM
... it seems, the board is the constant current driver (set/defined by the trimpots) - so only the wires to/from the diode, what's better than a separate CC-chip.

If you can't get/find infos for your driver, then drop it and search one with available infos ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org]
Call for the project "garbage-free seas" - [reprap.org]
Re: help with cheap china laser 5.5W
March 09, 2018 05:50PM
Thanks Viktor
Re: help with cheap china laser 5.5W
March 09, 2018 10:25PM
I have an arduino with a cnc v3 shield moving the head around.
I put an led on the spindle speed output and can turn it off and on, and dim it.
is there a way to use this to turn the laser off and on via mosfet etc ?
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