Sorensen/Elgar Lab Grade SMPS - 1KW SMPS Schematics
Hi Guys,
Sorry for the delay. I will attach the Sorensen/Elgar schematics in two posts because of the size of the files. They are not huge, but I don't want to push it. Because each family of supplies include multiple drawings and multiple schematics, so I have them all in a zip-file.
Attached is the first set of schematics and details for the 1KW family of high-quality, lab-grade SMPS's. I actually own a few of these and they are outstanding power supplies! They are very well regulated, the output voltage is very clean with only tiny amounts of ripple at the switching frequency, the meters are pretty accurate, they have ten-turn pots for very precise E and I adjustments, and they run very cool even under large loads. My biggest complaint about these supplies is the fan noise! They use an AC-powered radial blower to keep the switching FETs and secondary diodes cool, but I think it's overkill for normal use. They should use a temperature controlled fan so it's only that noisy when it's hot and working very hard. My other complaint is that the output capacitance is kind of large and the current limiting takes a few mS to respond. So when connecting a light load to the supply's output, there will be a momentary current surge until the current limiting drops the output voltage so the current is where it's set. I blew-up a couple LEDs because the surge current spike was high enough to damage the junction before it went into limiting. But using a 1KW supply to power a 40mW LED does seem a tad ridiculous, I guess. I picked up all of my 1KW supplies cheap on eBay because they supposedly didn't work. But, as was the case with all of these supplies I bought "not working," the only problem was that the programming dongle (a male DB25 solder-type connector with a few leads jumpered to "program" the supply's operating mode) was missing! When I made and added the dongles, the supplies worked perfectly! So I got a few $1,000+ supplies for $40 to $100 (plus shipping)!!! Watch eBay for similar supplies for similar prices - they turn up every now-and-then! And now that you have the schematics, you can fix them too!
Anyways, I hope everyone enjoys these schematics - I sure do! As always, I would also love to see your feedback about these supplies, your opinion of them, if you have experience with them, if you own one of them, if you can use the schematics to help your DIY work, etc.
After this one, I will post similar info on the Sorensen 3KW SMPS. I have one of these bad-boy supplies too, a DCS80-37, and it "doesn't work" either (it may just have the same dongle "problem" too - I hope) and I got it for $75 + S/H, but I plan only to fix it and just sell it. A 3KW Sorensen SMPS would be a little slice of test equipment heaven, but feeding this monster is just a tad more than my spindly little extra-bedroom wiring can handle. Besides, I can use the $$$ too.
Enjoy!