Winfield Hill wrote...
Spehro Pefhany wrote...
If you need only one, an easy solution is to haunt eBay for a few
months, looking for an appropriate Sorensen or Zantrex programmable
switching supply, going for about $300 to $400 per kW.
For example, a Zantrex XHR 300-3.5 does up to 300V and up to 3.5A.
http://www.xantrex.com/products/product.asp?did=223&p=9
http://www.xantrex.com/support/docdisplay.asp?prod=56
Their XFR 300-9 handles up to 9A. Also, made in Canada, I think.
http://www.xantrex.com/support/docdisplay.asp?prod=55
If you want to build your own, the construction techniques in these
supplies bears examination. A PFC input stage to 340V or so, then
a phase-shift-modulated zero-crossing soft-switching PWM H-bridge
driving the dc-dc transformer, ucc3895, etc. Big low-loss diodes on
the output. An elegantly-spare cooling system, with paper shrouds.
Hmm, probably at least a month of engineering time to start. :>)
Spehro Pefhany wrote...
Thanks guys, esp. Win for answering the main question and
anticipating the follow-up.
One other suggestion for a quick first-pass on an operating power
supply: purchase a 2 or 3kW switching supply (any voltage) on eBay,
study its design, and modify it for your desired output-voltage.
See
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3801663856
This means rebuilding or redesgning the dc-dc transformer, a task
you are certainly up to, replacing the rectifier diodes and output
electrolytic with appropriate higher-voltage-rated parts (an easy
task), replacing the relevant feedback resistor, and other stuff.
You can concentrate on Sorensen DCS, DLM and DHP designs that were
the inspiration for the Zantrex supplies, because Sorensen sells
repair manuals with schematics, compared to Zantrex, who refuses.
Once you have a working model, you can boot-start your own design.
One issue, the older designs don't have PFC input stages. The
DCS data sheet says for 3kW: "190-250 VAC, three phase, 14A; or
200-250 VAC, single phase, 20A. Note: Maximum power output of
3kW supplies must be limited to 2.5kW for single phase input."
But if you use 3-phase power, the lack of PFC isn't so important.
Thanks,
- Win
whill_at_picovolt-dot-com