The idea is to use a signal generator to generate 3 - 60Hz signals 120 deg out of phase with each other (3 Ø power) into a class A or A/B small signal amplifier on seperate channels (Probably Pro Audio Gear). Then into a step up transformer, or a voltage doubler to drive an inductive load.

Current supply would come from rectified AC I suppose, and I would almost certainly be using a 3 Ø regulator (such as ATO Model: ATO-PRG-4340 / 4-Wire 3-Phase SCR Power Regulator)

Think it would work? Provide clean reliable power? Any design suggestions?

I dont need much, only 70-90A @ 230V OR 40+A @480V LOL!

 

I dont need much, only 70-90A @ 230V OR 40+A @480V LOL!

And where do you expect to find 20kW audio amplifiers and the power to operate them?

 

I had no intentions of using audio amp for that. only to develop my signal above 1VPP. To around 100w or so. It should also give some output control to tweak to final signal.

edit
Oh also I have 240V @ 200A service, so I think I'm covered.

 

I had no intentions of using audio amp for that. only to develop my signal above 1VPP. To around 100w or so

So what are your intentions?
Where are you getting the 100W (if you don't need 20kW as you stated)?
Do you understand you can't get 100W power out without a 100W amplifier?

 

Ok, so basic amplification uses a 'front end' such as 741 OP amps etc to develop small signal such as those from a tuned circuit received through a radion antenna to make a signal apropriate to drive a larger transistor. A signal generator, is typically precision equipment and it would not be apropriate to couple it directly with a large transformer (in my opinion) therefore I propose to use a amplifier that typically receives a 'line level' 1VPP signal to couple it with another device, such as a step up transformer, or voltage doubler.

To do that I would guess it would require a much larger signal to acheive the desired output. Hence the 100 or 200 watt small signal amp.

 

want to explain why?

 

Thats not really an answer, like defining a word with the word itsself. You called me a 'crackpot'. Rude ok, but there are alot of internet 'toughguys', and my feelings are not brusied, but if you are going to say something like that I would expect you to explain.

I came here for opinions or thoughts, snd the reply did not reflect, in my opinion, a thoughtful response based on what I wrote.

Example, I never said I intended to develop '20kW with audio amplifiers' only that I had considered to use an off-the-shelf audio amp as a driver unit. nothing more.

Moderator's note: The offending post was removed. You can use the report button to bring things like that to our attention.

 

You seem to have no firm requirements of what you want.
For example where did this off-the-wall requirement come from: "I dont need much, only 70-90A @ 230V OR 40+A @480V"

 

I was trying to be cute. I need less than 100A @ 230V. Typical usage I am expecting around 60A.

I prefer to overbuild

 

I was trying to be cute. I need less than 100A @ 230V. Typical usage I am expecting around 60A.

So you looking for a off the shelf 13.8kWatt amplifier instead of a
20kWatt off the shelf amplifier?
And please don't say you wish to find a 20 jigawatt flux capacitor to go with it

 

no, i was hoping to use some 'off-the-shelf' equipment to assemble an analog 3 phase power supply without igbt, designing circuit boards etc. providing a nice clean signal.

I'n my mind a signal generator produces an ideal signal, just need to get it bigger. preferably without big power transistors.

I was a decent repari tech in another life, but never so good at design. anymore I have no time for it either. I have no appetite for overpriced equipment like phase perfect because it just doesnt have to cost that much. They only charge that because they can...

I really should not have tried to do this tonight. I am very tired. Been going 7 days a week for months.

I had some ideas in my head and wanted to float them by someone else for thoughts etc. Clearly I should have gone to bed

 

Clearly I should have gone to bed

That is exactly what I'm going to do right now sweet dreams. And forgive me if I offended you. And I know you're trying to be cute but I was born cute.

 

You still seem to have no real concept of the large (and impractical) amount of power you think you need.

 

I'm not sure how exactly to reply to that. The amount of power required is not what I 'think' so much as a calculated value. It seems most likely never to exceed 100A, however 60A is likely at times while 30 to 40A is a certainty.

A person could calculate their power usage AFTER using it; however I have no way of knowing exactly how long or how often equipment will be used, so some guesswork is in oreder.

It may seem impractical to you, given the amount of power, there are other factors I simply cannot change. Single phase equipment does not exist, and this is already in my possesion.

I could pour a pad, call Genrerac, and have a unit delivered this week. They make nice equipment. I dont think its worth the 20 to 30k they ask, and in fact, I have that kind of money to spend. The reason I have that kind of money, is that I dont problem solve purely through spending. I believe its possible to acomplish the same goal for a few thousand -ish. Maybe it isnt.

Despite being called a 'crackpot', it seems reasonable to produce a small signal (signal generator), couple it to a power block (through a small audio amp), the power block is the problem I have run into. I can supply a DC current source, but I need to couple it with my AC signal. Thing is I dont want to use transistors. I'm no good at amplifier design, and have no desire to do so. I can troubleshoot them, replace parts, make them work etc, but if there is no other way, then I will take another path to my resolution.

Coupling transformers, diode switching. I dont know. I have as limited amount of time for research, I was hoping some people here more learned than myself would have some useful ideas. Unfortunately, all I hear is 'Give up'.Well, you don know me. I will try until I succeed, or the wheels fall off.

I have, and can wind custom transformers, so if thats a part of the soulition, that would work. Designing and contructing an a complicated circuit from scratch. A few tranformers, caps, diodes is ok. Custom PCB's, not ok.

RPC's will not work as they rely on split-phase power, and the phase/power correction seems to be a nightmare, and only partially effective (full load).

Digital power converters are over priced, in my opinion, but they have the right idea: flatten the signal and start from scratch.

This idea is not my only path. Another option is just to get a generator head and attach it to a 4 or 6 cyl diesel est: $4 to $6k not bad really.

But I really want to explore a non engine-driven option first. If something is not possible then its not, but if I listened to nay-sayers, I would not have acomplished many things in my life.

 

I'm not sure how exactly to reply to that.

It is very disrespectful to waste time of those who wish to convey knowledge to others.Time is precious. It is invaluable. It is one of the powerful factors. Our life is measured in terms of time. We grow in time, live in time and perish in time. Time is fleeting. It is changing. It never stops. Neither does it wait for anyone. Time once lost it is lost for ever. Time moves at its own pace. It cannot be commanded. So, we should be careful about the importance of time

 

You won’t tell us what you are trying to do, it uses more power than a typical household’s peak usage, and you wish to accomplish it by some means that can best be characterized as magic. How, exactly do ypu expect us to help you?

Oh, and welcome to the forum!

Bob

 

if I listened to nay-sayers, I would not have acomplished many things in my life.

We are not nay-sayers, we are just trying to convey to you that Mother Nature doesn't give you a free lunch or allow you to generate power from nothing (it's called the conservation of energy theorem) which you apparently don't understand.
But if you want to waste you time on some sort of free energy or over-unity design, have at it.

 

@Delta prime
It is difficult to mount a response to someone who believes they know what in your mind
crutschow wrote:
"You still seem to have no real concept of the large (and impractical) amount of power you think you need"

@
BobTPH
There are a few machines that will be running, but probably never at the same time. One is an electron microscope, another is a CNC machine, some motors, and a welder. These are for a product a colleague and myself are trying to develop. I believe I can get 2 more 240 lines @ 200A each

It may seem like magic, but I only suggested it as an idea, I am not a designer of electronic circuits, which is WHY I'M HERE, asking people who do. If something wont work, all anyone has to say is "It wont work like that, you need..."

As far as help, I am curious if there is a reasonably simple way (ie. Transformers, capacitors, diode) to couple a DC current source onto my AC signal without using transistors, if not, this path will probably not work for me. I can make the AC signal very easily, and I can flatten the line voltage for a DC current source

I worked in an electronics related field in the military around 30yrs ago, after that I ran the tech dept at an Equifax Affiliate for awhile, then repaired consumer electronics, before they became disposable, ran a computer business for a couple of years, before starting a residential remodeling business where I made my money. I have been in an unrelated field for over 20 yrs.

I read in a thread online where a guy had built one of these Rotary Power Converters, he had been an Electrical Engineer for over 30 year, and he said that his experience didnt help as much as you would think. Now I know the feeling.

@crutschow
This is not any sort of free energy idea. Power coversion pure and simple. I have noticed me and you have an open circuit between us. Please try and carefully read what I am writing.

I know the law, and I will get less out. hopefully it will be clean from an analog source. Digital is very difficult to get clean for precision equipment.

I DO in fact appreciate any/all time everyone has donated to this thread; however I havent seen any helpful suggestions or ideas, so this is probably a dead end...

 

I havent seen any helpful suggestions or ideas, so this is probably a dead end...

You haven't seen any helpful suggestions because you haven't given us a clear idea of what it is you are trying to do or why. Withholding information is no way to get good answers.

As I understand it, you want to take a signal from a signal generator and amplify it to about 20KW of power, without transistors. I suppose you could do it with vacuum tubes... I do not know of any other device that might do that kind of power amplification, especially because you want it done "cleanly," as you say.

Here is a helpful suggestion. Rent some industrial space with 3 phase 480V power available.

Bob

 

I havent seen any helpful suggestions or ideas, so this is probably a dead end...

Seems so.
Your requirements are vague.
You (apparently) want to generate AC power but you can't generate that from nothing.
For example, you say:

I can supply a DC current source,

Okay.
So where does this "source" get its power?
And converting that to AC is normally done with a transistor inverter.

If you need 10kW of power then something has to generate that 10kW.
That is normally done with a engine powered generator or large solar panels if you don't have mains power.

If there were a simpler or better way to do that, then it would already be done.

That is as helpful as suggestion as you are likely to receive.