Potential high power diode supplies

[macona]

I have come across some Astec DC/DC modules that might be good for big diode supplies. They take 200-400vdc in (Doubled 120v mains) and output .4 to 2.6vdc at up to 60A or 100W. They have a current limit mode built in too. Astec does not have any info (I called) but they are close enough to the AM80A series modules that I was able to figure out how to drive them. They can be put in parallel too for more drive current.

The only problem is I get a ring pulse every 3.5us. It looks like I can use a LC filter to clean it up but I dont know how to design an appropriate one to do that. Can anyone help?

If these work out there will be about 150 of these available.

This is what it looks like on the scope, 200mv/div 10x probe, 1us div:


IMG_1692 by macona, on Flickr

The modules themselves:


IMG_1694 by macona, on Flickr

[VDX]

... my 9W and 25W IR-diodes needs max. 9Amps, so I'm driving them with up to 5 parallelized current regulators LM317 (1,5A max / 1A continuous), LM350 (3A / 2A) or LM338 (5A / 3A) with configurable max. power and 'finetuning' with PWM and without any visible ripples in the scope.

But this 60A-modules could be interesting for a coherent diode, that needs up to 35Amps ...

Viktor

[macona]

That is what I am thinking. I have a couple 50watt faps that run at 60A each. I would need two modules for each.

[VDX]

... what's with pricing and shipping to Germany?

[Meatball]

You need to expand the time scale to get an idea of the ringings' frequency. May take some large components though since we have access to the internal circuit.

[macona]

Looks like about 70MHz.


Untitled by macona, on Flickr

[-bart-]

How much do the pulses bother you ?
I mean, you don't expect these pulses to be visible, do you ?

You could use a low-pass filter @50kHz or a notchfilter @70Mhz.
Be sure that the used inductors have a resistance that is much lower lower than the resistance of the load.

http://www.wa4dsy.net/filter/filterdesign.html

[macona]

Wont these spikes kill a laser diode? Are they too short to do damage? If not I wont bother.

VDX, I am not sure how much they will be. I need to get them off the boards they are attached to. They will probably be available after the new year.

[mixedgas]

Ok, Lets load it with a simulated diode. That generation of switcher needs some TLC to feed it and load it. Clock in is used in older switchers to sync modules. It may need pulled high or low, or get a clock. Its "hiccupping" looking for a load. What other pins are hidden under the switch?

I looked at the AM80 data sheet. That data sheet has been driven to mediocrity by marketing wussys. I am not impressed, unless there is a seperate PDF elsewhere.

Steve

[mixedgas]

I got a better idea. I go to lunch with a switcher designer at work. Test and see if this occurs with more then one sample. If it does, get one here in a box with return shipping. My friend loves to pulse laser diodes with ultrafast pulses, thus knows the score on LDs. Let's let him chew on it. He has the lab to do, too.

Steve