I've always thought that the only place you'd get a three phase PSU was from an industrial supplier, but it turns out eBay has everything.
This really nice unit is sold as being for a 380V AC supply (two phases of a Chinese 220V supply), but on the manufacturers site it suggests it has a range of up to 528V AC and 746V DC. I'm not sure I'd push it that far though.
The module is clearly made to industrial standards. Really good separation and what appears to be a proper isolated transformer design, with well placed components and a bias towards reliability instead of cost. One particularly nice feature is the output overvoltage safety net of a second simple voltage clamping zener in the feedback circuit, so if the voltage reference fails the output voltage will only go up by a few volts.
This has to be one of the best looking power supplies that I have seen that isn't a prominent brand like Mean Well. It's perhaps notable that this company is called Munpower and has a logo that hints at the Mean Well logo.
Some equipment has two or three phase supplies, but no neutral. That's where this module could be used to provide power to control circuitry. It might also have uses in DC electrical traction equipment. Some extra VDRs/MOVs to clip voltage transients would be useful if doing that.
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This really nice unit is sold as being for a 380V AC supply (two phases of a Chinese 220V supply), but on the manufacturers site it suggests it has a range of up to 528V AC and 746V DC. I'm not sure I'd push it that far though.
The module is clearly made to industrial standards. Really good separation and what appears to be a proper isolated transformer design, with well placed components and a bias towards reliability instead of cost. One particularly nice feature is the output overvoltage safety net of a second simple voltage clamping zener in the feedback circuit, so if the voltage reference fails the output voltage will only go up by a few volts.
This has to be one of the best looking power supplies that I have seen that isn't a prominent brand like Mean Well. It's perhaps notable that this company is called Munpower and has a logo that hints at the Mean Well logo.
Some equipment has two or three phase supplies, but no neutral. That's where this module could be used to provide power to control circuitry. It might also have uses in DC electrical traction equipment. Some extra VDRs/MOVs to clip voltage transients would be useful if doing that.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
http://www.bigclive.com/coffee.htm
This also keeps the channel independent of YouTube's advertising algorithms allowing it to be a bit more dangerous and naughty.
Nice
In LED ceiling lights I’ve had power supplies fail with no obvious burnouts.
After replacing the power supplies a couple of them failed too.
Are there types of LED power supplies that are more dependable?
Mains are 110 volt.
LEDs are 4 in parallel with 9 sets.
Cheap Walmart lamp: TH-LJ08-190mm
18w-5730-4B9C-LED
Thanks for any help.
FYI, in Japan, three phase runs as Delta. It has no neutral, only earth. They run 200V between phases and 100V between Line and Neutral. For some appliances (e.g. air conditioning) there are 200V single phase.
There's some odd stuff out there all right. I have a pile of switching power supplies, salvaged from some IBM equipment, that have an input voltage spec covering two different AC line voltage possibilities, and a 300V or so DC input spec! The output is 37VDC. Why 37V? My guess is to feed that into local 3-terminal linear regulator chips. No idea what I'm going to do with these things, but perhaps I'll figure something out…
Look! A Chinese product with character. Now that's refreshing!
haha, MOFO of a MOSFET
There really is nothing "three phase" about this switcher. It is single phase input which just happens to accommodate voltages found in 3-phase AC circuits. True 3-ph switchers do exist, but are generally very high power (multiple kilowatts).
The current sense resistor in the source circuit of the FET is actually the means by which the inner loop control is done. Most of these simple switcher circuits use two control loops – and inner "current mode" loop and an outer "voltage mode loop." Each switching cycle is terminated when the voltage across the sense resistor reaches a level set by the output of the voltage error amplifier. In some ways it adds complexity but it can make frequency compensation of the main voltage loop simpler. It DOES protect against overcurrent, but that is very much a secondary function. On the topic of overcurrent – Fuses at the input of a switcher are really just there to prevent fire and perhaps keep the tracks on the PCB from being burned off. I've always regarded them as utterly useless for component protection because switcher failure is frequently catastrophic (eg. switch fails short circuit, leaving only the resistance of the winding and the sense resistor across the AC line input).
I note the main "transformer" (not really a transformer in the normal sense, but an inductor with two windings, one for charge and one for discharge) is on a "PQ" core. I've used PQs in designs from 150W to 1kW. They have a well optimized window and better self-shielding than many types. They are a bit more expensive than cores like EE. You can get very nice metal assembly clips, which can be a big improvement on just taping or gluing the core halves together. Because this is a flyback converter the centre leg (which is round) will be gapped. Almost all of the energy storage is actually in that gap.
The double or triple insulated wire can be a real boon, though it is a heck of a lot more expensive than magnet wire. It allows using the full window height of the bobbin while meeting stringent creepage distance requirements. Some of the VDE standards required 8 mm creepage distance, meaning you could lose 4 mm from each end of your bobbin height. If you start out with a bobbin of 15 mm height it doesn't leave much for the windings. You also don't have to fuss with extra sleeving to get the windings out to the bobbin pins.
Anyway, it's time for me to quit watching SMPS videos. I've designed a lot of them and developed a passionate hatred for them in the process. They are miserable in many ways and everything is in conflict with everything else. I quit doing it years ago and I really shouldn't even be thinking about them anymore.
What’s a circuit but a story teller with functionality.
I really find your explanation of ccts, although l can read ccts and understand the basics I've not got depth of knowledge that you have so l find your diagnosis rare down very enlightening! I've mainly worked on transmitter repairs Lf to Hf 20w to 20kw some Marconi Hf auto tune,intresting thing was auto tuning always got lower I P, s inter modulation products! Than l could get on manuel tuning! On H f tx! Also uhf txs 500ml w to25w, l once saw the result of standding wave on mistuned 10kw hf tx that set fire to AE patch panel,that happen whilst l was in middle of manuel tuning, and main supply failed,and as usual despite d o e resting standby generator every month, as usual it failed to get up to speed to produce 240v so l had to go outside to generator adjust speed regulator! so by time l got back in tx hall, only2mins tx had come back on line,in mistuned state and standing wave just happened to meet @AE patch panel plug setting on fire! There was a b.e.r.s site on island, British eastern relay svs l got to pay visit to they had mega w tx,they show me result of mistuned tx,feeder to AE size of large drain pipe 2ft dia,it had melted/blown hole in aluminium feeder! This bit you'll well understand, they had2 very large paxman generators, can't remember power!must have been meg watts for such high power HF tx. Sombody had really bad day when running up standby gen and getting the phase out of alinment with on line gen,as in for change over,there was friging humus bang, alternator stalled engine,which promtelly blew engine up,very big deisel engine, that then despatched it's self thro roof of building, engine size of around 2double decker buses, really bad day for BBC facility shut down for repair for some time,theyve moved now from island to mainland Arabia. Short distance across sea.
Seems a lot of gubbins and effort, nicely done, I tend to just take off 240v from one of the phases for my control, contactors, relays etc. for invertors for motor drive…..
what the devil is sqrt(3)? It is sqrt(2). 3 is for 3 phase. Does China or UK or EU supply 3 phase to the public?
3 Phase industrial power supplies dont usually have a Neutral. But most of them have a ground and a metal casing.
I believe China is now a world leader in electronics and I have not been dissappointed when buying their products on Ebay. Their mainstream electronics are excellent and a bargain, but then you can come across 'scam' items claimed to improve health, etc. (air ionizers and that sort of thing).
I miss videos on more complex circuits like this.
Extremely clear description of the entire circuit. A joy to follow along! Only suggestion would be to add transformer winding dot notation on the schematic for added clarity.
I know I'm a year late, but it appears our 33RC3 is actually a NCP1251 by On Semiconductor
Hadn’t a clue what this video was about !
An issue that often arises in valve amps comes to mind here. When putting the two 68uF caps in series, the exposed end of one of the cans will have 250 – 300Vdc on it!