Making low voltage PS for 40W diode

[CompWiz]

Those windings were not THAT hard to get off. The core is welded near the bottom, the weld in only a few millimeters think, and can easily be cut with a hacksaw. Then you have to get the primary off without wreaking it.

After that you can pull the secondary off, but it required a hammer and chisel.

Then I just slipped the primary back in place.

You have to clamp it together to use it, otherwise it will vibrate like crazy.

PS, the MOT is still for sale if anyone else wants it. Seems potatorage lost the diode in the mail.

[uk-laser]

The quickest way I have found of getting high current, low voltage AC is to put an overwind on a torroid. I have used this for Argon heaters in the past.
I used a 120VA torroid with (IIRC) 7 + 7 turns of cooker wire for a 1.5V,0,1.5V centre tapped 30A heater.
Fine tuning the number of turns lets you fine tune the voltage.

Unfortunately high current low voltage 50/60 Hz AC is not a great starting point for a High current diode supply. In order to reduce the ripple voltage to something acceptable you need a LOT of capacitance. If you could live with 10mV ripple you would still need 1 Farad of capacitance per Amp you were intending to draw.
A 5V 33F capacitor (or more likely 10 x 3.3F in parallel) would be more expensive than buying a Vicor brick.
Just using a 2V Vicor and trimming up the voltage whilst monitoring the diode current will get it lit but leave you vulnerable to thermal run-away. You do really need some form of active current control.

Best starting point would be a 3.3V Vicor brick (or other high current 3.3V supply) then a diode driver running from the 3.3V. Yes, you are wasting 30 or 40W as heat but it will give you much better current control.

Regards,
Robin

[Xytrell]

...however, you will need a current clamp to find what current you are running it at.

Why won't a shunt resistor work?

[drlava]

Probably the simplest way to run it is to find a 2V Vicor DC-DC converter and use the trim function, however, you will need a current clamp to find what current you are running it at.

Seconded on the vicor. They come up on ebay a lot, but if you want modulation you won't want to directly connect this to your diode. I'm modding a FlexMod for a high current project a lot like this. In combination with a vicor DC/DC (5V), it will be an efficient, compact solution. If you want modulation I can forward the details on, or for another modulation route I'm sure the forum can help develop a high power controller.

[MechEng3]

I have a few 20 watters here in a project and would be very interested in driving all 3 diodes. Even with 3 drivers. I have a 5 v supply to handle up to 60 amps out. That should take care of the dc side of things. I have plans of side pumping a YAG rod and doing some simple G code CNC burning/labeling of items...aluminum engraving...blue jeans....leather items. Plus I would have a cutting option.

[sugeek]

http://cgi.ebay.com/Laser-Diode-Driv...mZ230362847164

I found one listed at my old surplus shop, now I have to drive 5 hours to get to any... I know he had another in stock as well as a few CO2 lasers, the price is a bit high but you may be able to haggle.

-Adam