Split phase capable lab supply @ <300V @ 10A (30A outlet) - Page 1
Forum section: electronics / testgear

author: coppercone2
author_rank: Super Contributor
timestamp: December 29, 2018, 02:05:59 pm
content: whats a good lab power supply for these power levels assuming you were actually going to buy it?Say something nice and cheap for the required power levels like a LAMBDA ESS series (only problem is that its 3 phase).If you use a 30A split phase outlet, it could be a reasonable test for a system, even if you derate the old ebay equipment. I just used 60% efficiency instead of the 80% quoted in the data sheets for supplies as a derating factor.Does anyone know what a good supply that can run on split phase is for this job?If this thing ran on 2 phase, would it be good for prototyping H-Bridges and stuff prior to releasing them into the waters for further testing?https://www.us.tdk-lambda.com/hp/pdfs/data%20sheets/ess-data-sheet.pdfIt seems to have alot of nice features and be pretty robust. I am not sure if I should bother looking for something capable of split phase operation at high power levels.The ESS are reasonable on ebay, under 4000$.After this I think the rational next step would be to get a AC-source that can deliver clean AC @ high power levels to test frequency/voltage response after DC operation is established, then run it through a big transformer for surge limiting.Or do they just not make lab supplies for split phase and I need a inverter or other 3 phase generator?

author: coromonadalix
author_rank: Super Contributor
timestamp: December 29, 2018, 05:06:23 pm
content: If you want to play with theses kind of power, you could make an electrician add an 3 phases transformer in your home electrical system or add an 60 amps outletEx : for a Spa thubA Friend of mine played with high power tubes amps, had his electric box modified .... $$$ but it worked, i never saw his electrical bills loll-----------------------------------------------------Sourcehttps://www.quora.com/What-is-the-difference-between-single-phase-and-three-phaseMost US industrial facilities use a 3 Phase 4 Wire 480Y/277V power arrangement because of its power density. Compared to single phase power circuits, three phase power circuits provide 1.732 (the square root of 3) times more power with the same current.Using a 3 Phase power arrangement saves on electrical construction costs by reducing the current requirements, the required wire size, and the size of associated electrical devices. It also reduces energy costs because the lower current reduces the amount of electrical energy lost to resistance (converted to heat).there you have some explanation (s)-----------------------------------------------------But i would not play with 2x "out of phase 120v outlets", an good electrically done panel would have all its outlets in phase and be well "earth grounded"I did check all my outlets, 1 was not okay (line and neutral reversed)

author: coppercone2
author_rank: Super Contributor
timestamp: December 29, 2018, 05:23:50 pm
content: i only use it for welding but i guess i should just use a rotary converter. dont want to deal with power co

author: amlu
author_rank: Contributor
timestamp: December 29, 2018, 05:42:15 pm
content: Not that familiar with US mains wiring, but looks like the outlet can produce 240V when connected across 2 phases?May be possible to use an EU market unit working on 240V? Not sure about frequency, some may have no trouble running on 60Hz instead of 50...Budget solution may be an adjustable autotransformer, use it to regulate the voltage, convert to DC with a diode bridge, find some capacitors rated for the voltage to smooth it out and there you go.

author: nctnico
author_rank: Super Contributor
timestamp: December 29, 2018, 05:50:59 pm
content: Quote from: coppercone2 on December 29, 2018, 05:23:50 pmBuying a welder is probably cheaper. I'm not sure whether a power supply likes to be used as a welder.

author: coppercone2
author_rank: Super Contributor
timestamp: December 29, 2018, 06:20:59 pm
content: you misunderstood, I mean I only use the split-phase hookup for welding, I never powered any equipment off of it other then a plasma cutter, mig and stick welders.I want to use the PSU for development of custom equipment, possibly even welders, but I don;'t intend to do anything then testing off of it.What is the proper tool for developing a plasma cutter, welder, induction heater, plasma supply, motor driver, etc?The design process I had in mind1) build control electronics, H-bridge/power controller (maybe not always H-bridge)2) do load testing on robust lab power supply (what I am looking for)3) do process testing at reduced load to the limits of the derated supply (its $$$)4) do testing like noise injection into controller, etc.. all while hooked up to current limited precision lab supply under some load, eventually to max5) develop AC side of power supply, including protection, filtering, AC-DC conversion for rail, inrush, PFC5) test AC side alone on "AC Source" unit with loads etc6) combine AC and DC side on AC source unit. Probobly run at reduced load and do things like LISN tests for known good supply, noise injection if safe, radiated emissions rough in, etc7) Test unit on line voltage, LISN test, over load testing, etc (whatever can be done, this step is still in development, quite complicated). This is the 'out in the wild test' conducted with the more 'primitive' equipment like VARIAC and/or some kind of saturatable reactor at higher power levels, realistic line impedance, etc. Basically full power above the efficiency of the lab power supply, AC source. Possibly with things like surge-loading testing by peak switching, effect of real mains interference/nonidealities.use unit for whatever workshop stuffThe idea is to be able to use the same good precise work practices as you do with microelectronics but on a power electronics scale up to 300V/10A or so, for 'breadboard' type testing (obviously not on a bread board, meant to be safer, but I mean like power electronics Manhattan prototyping in special test chassis etc.I don't like the idea of using unregulated voltage or weird electronics for testing purposes that would seem cheap in a microelectronics laboratory (i.e. who that is seriously interested in learning and testing (not just getting it done) would use a unregulated line connected supply for doing bread when they are interested in things like spectrum analyzer measurements?). I want the same care and precision of the microelectronics laboratory in the power electronics laboratory.The design may not even go into AC side development (other then testing), for instance if an appropriate switching regulated supply is found (like a meanwell type deal). It would likely be safer & more reliableBut I still want a adjustable lab supply that can be used for DC side development.Sorensen has me covered up to around 600W@150V

author: nctnico
author_rank: Super Contributor
timestamp: December 29, 2018, 07:08:09 pm
content: What you can do is use several PSUs in series and divide the load over several breakers. That is how I solved a similar problem in my lab.

author: coppercone2
author_rank: Super Contributor
timestamp: December 29, 2018, 07:28:31 pm
content: hmm those sorensens can be combined. It might be a better idea since you can also use them possibly to make bipolar rails for high voltage audio, ultrasonic, RF or piezo amplifiers.2 150V devices would do the job well. I think you would need serious money to go higher in voltage/power. And I don't know what the use would be?