cost of big ass constant voltage transformer? - Page 1
Forum section: electronics / projects

author: coppercone2
author_rank: Super Contributor
timestamp: August 24, 2018, 07:47:43 pm
content: If you wanted to supply your entire house with a constant voltage transformer (say 200A), how much would such a beast cost?What downsides are there to doing this besides cost? I like how it regulates without tap or silicon in it.What do the performance of large CVT look like typically in regards to passing surges and capacitance/filtering effect?Do they have big ones that can do split phase? Or would you need two and then some kind of phase shifter to match the phases? Could it scale to three some how if you ended up getting three phases?Yes, I very much dislike the power company. When I think about the situation and the specification they provide us with it drives me insane. I thought about mechanical isolation and regeneration of power as well, but I shy away from moving parts for home infrastructure. Maybe if it had magnetic bearings. And it would still need a CVT to power it to ensure torque stability from surges, so all it could do is reduce the number of CVT.No, I refuse to put a toilet in the basement either, shit must flow with gravity. I would rather have a ladder and a second bathroom upstairs lol. How disgusting is it when you think about a basement bathroom pump? i wanna vomit

author: SeanB
author_rank: Super Contributor
timestamp: August 24, 2018, 09:08:13 pm
content: Downside is the no load current is very high, a 200A unit would effectively use 50kVA on the input, and power factor for them is horrid till the output is near full load, where it will approach 0.8 lagging power factor. It will, for the 50kVA unit, probably dissipate 10kW of heat, and would be a half ton block of copper and iron, about the size of the pole transformer that supplies your house, and with an associated film capacitor of similar dimensions as well. they are fine for small loads, where you are running at near the rated load, and need the voltage regulation they provide. I have a 1kVA unit that rarely gets used these days, I used it to get a low noise power supply for AV recording equipment, where the 200W or so of heat it generated was not an issue compared to losing recordings due to conducted mains noise. It made a great isolation transformer, which is why I still keep it around, despite the weight of the thing.

author: coppercone2
author_rank: Super Contributor
timestamp: August 24, 2018, 11:24:27 pm
content: rofl I thought they had better properties then thatmaybe if I lived in Antarctica it would integrate well into some kind of heating system.I do still want a small one though for lab uses.

author: ArthurDent
author_rank: Super Contributor
timestamp: August 24, 2018, 11:30:17 pm
content: Because most modern pieces of home electronics, kitchen, and other equipment will operate over a fairly wide voltage range, a whole house regulator would be a total waste, not to be confused with what you don't want to pump out of your basement.

author: coppercone2
author_rank: Super Contributor
timestamp: August 24, 2018, 11:31:55 pm
content: some things don't like it.What is the industrial name for some kind of motor driven generator isolation device of significant size?https://en.wikipedia.org/wiki/Motor%E2%80%93generatorAre there any trade names or brands for these gadgets or sets sold that can be useful to know when shopping?

author: schmitt trigger
author_rank: Super Contributor
timestamp: August 24, 2018, 11:44:04 pm
content: Are we talking about ferroresonant transformers?In addition to what Sean mentioned, those beasts produced lots of acoustic noise.

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: August 24, 2018, 11:50:19 pm
content: Never had one that didn't run hot and hum like crazy. Used to run my photo enlarger off one. Awful things. A motorized Variac works better. General Radio made some in the past, and somebody probably still does. I don't know if that would be practical for a house, but it certainly seems unnecessary.

author: coppercone2
author_rank: Super Contributor
timestamp: August 24, 2018, 11:56:30 pm
content: I was thinking the CVT (not sure if its the same thing as a ferroresonant transformer used for backlights) would have the best control loop other then silicon. Any thing else will be slow to respond (mechanical governator thingy controlling a gearbox or electric motor or relays), so it would take the loads off any kind of protection stuff like MOV as much as possible when there are quick surges. The MOV is like the annoying component that degrades slowly from what I understand.You could install a giant reactor infront of the CVT to limit the draw of current on a no load condition I think?

author: TERRA Operative
author_rank: Super Contributor
timestamp: August 25, 2018, 03:55:04 am
content: I have a Matsunaga Automatic Voltage Regulatorhttp://www.matsunaga-mfg.co.jp/(that I never use) that is essentially a motorised variac with output voltage sensing.Not so good for transients, but will work well with slower voltage changes.Maybe something like that for your equipment will help?

author: coppercone2
author_rank: Super Contributor
timestamp: August 25, 2018, 04:31:16 am
content: Nah I trust the equipment I have is pretty good I was just curious about a fast solution, I know you can do alot of things with motorized variacs. They do look pretty practical compared to this other stuff.Rotary tranformers and CVT i am clueless about

author: filssavi
author_rank: Frequent Contributor
timestamp: August 25, 2018, 05:24:03 am
content: Guys we are in 2018 not in 1965, what the OP needs is a always online UPS, they always run the battery ( no bypass) so they smooth out any crap the power company throws at you. It won’t be cheap( not that half a ton of copper and iron is anyway), and you will need to replace the batteries once in a while, but still it is a much prettier solution

author: coppercone2
author_rank: Super Contributor
timestamp: August 25, 2018, 05:27:43 am
content: there is an appeal of simple low component systems vs some crazy shit with battery chemistry, advanced semiconductors you can't inspect, microcontrollers, etc.buzz off? I have plenty of UPS but this thread is not about UPS, I don't go into valve threads trying to shove transistors down peoples throats or go into threads about analog filters ranting about FIR code.At least get some data to compare about reliability, repair ability, mean time before failure, etc. I feel like I got spam mail right now. What is the point of your post? You just come in here, restate what's been said and say we are outdated or something.It's not constructive and you have nothing to back up your assertions besides cost and personal familiarity. It might end up being that the post is only interesting because it highlights technological progress but you are not showing it and trying to derail.

author: David Hess
author_rank: Super Contributor
timestamp: August 25, 2018, 06:01:25 am
content: Ferroreasonate transformer are not particularly efficient except close to their load rating. I think you would do better with a motor-generator or maybe even a synchronous capacitor if you could find one intended for split phase 240 volts.Some online UPSes can be used as super power conditioners without their batteries. I just have several for specific loads like my workbench, computers, and network gear.

author: filssavi
author_rank: Frequent Contributor
timestamp: August 25, 2018, 06:37:39 am
content: Well if in your original post you said explicitly I want a transformer because I like it, then fine I wouldn’t have commented, however it looked like you wanted to actually solve a problem (bad power quality) so I provided the best solution available now, a UPS is cheaper, more efficient, smaller, lighter, and it actually protects you also from brownouts, it however appears that you just want a transformer for the look of it (or maybe because you don’t trust silicon (as with any audiophool worth its name) anyway I’m not beating on this dead horseGood day sir

author: PointyOintment
author_rank: Frequent Contributor
timestamp: August 25, 2018, 06:47:38 am
content: Quote from: coppercone2 on August 25, 2018, 04:31:16 amRotary transformer isnot what you want.

author: intabits
author_rank: Frequent Contributor
timestamp: August 25, 2018, 12:33:53 pm
content: Ferroresonant or Constant Voltage transformers do vary a bit.Some are noisy, some are not.Some produce sine wave output, some produce more like square waves.Some handle a fair amount of power for their size, some less so.They are most efficient running at their rated load.ALL are heavy!I did some experiments with some:-

author: ConKbot
author_rank: Super Contributor
timestamp: August 25, 2018, 02:04:35 pm
content: http://generaltransformer.com/ferroresonant-transformers/"We can produce ferroresonant transformers with ratings from 100 va to 10 kva for 50/60 Hz operation."Split the household loads into 10kva or less groups, and you're in business.No association, just the first promising search result.