High voltage current and voltage sources

I failed to mention some of the specs: DC, continuous operation, maximum 1000V, maximum 10mA-1A. At this point I'm only worried about the low end current range of about 10mA but in the future I do believe I might need possibly a 1000W supply

The short answer is that it is possible, but it would take a complicated, bulky and expensive circuit. Anybody who took the job on would want to know a lot more about what you were actually trying to do, and why.

If you don't want to publish the kind of detail in a public forum, you are welcome to e-mail me directly (the adress I post under here - bill.sloman at ieee.org - is real and works). It's unlikely that I would be able to do the job for you but I've got a couple of private e- mail adresses that might be able to help.

-- Bill Sloman, Nijmegen

Why do you want it to be transformerless?

How big is compact?

At 1000W it likely has to be mains powered. What is the mains voltage?

What does the load look like?

Can the output terminals look capacitive?

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Why not try this:

http://www.emcohighvoltage.com/Fseries.PDF

Fairly large, if it includes surface and airflow for extracting

1kW worth of heat.

A transformer would be smaller.

Cheers, James Arthur

Define 'transformerless'; a Model T spark coil generates high voltage, it's CALLED a coil but it's also an autotransformer.

An LM317 requires several milliamps output current for normal bias, so it won't do the low current range. As for high voltage, you can get amplifiers (grounded-base transistor) that take current at low voltage as input (emitter current) and generate current at high voltage as output (collector current). That means you can potentially separate the 'current regulate' and 'high voltage' problems.

There are (currently on the market) no good references for high voltage; the Zener diode, or bandgap reference, or integrated circuit regulator using them, will be a part of your low voltage section. There ARE some high voltage ICs, but unless you're manufacturing motor controls it's unlikely you can find ones that do what you want. Integration doesn't, in and of itself, constitute a virtue.

I've used 4.5 GV systems, which qualify as 'exotic'. Most of the

1kV-and-under electronic field seems ... domestic... to me.

On Apr 12, 11:56=A0am, whit3rd wrote: [.. good stuff ..]

MOSFETs as common gate stages work too.

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Oops...
Appearances can be deceiving.

Should work, with maybe some loop compensation added.

You can replace the NPN with an LM317 or an LM1117 and get current/thermal limiting for free.

And bypass the inverter input.

John

Sorry for not being clear and thanks for the replies.

I want to create several power supply from mains(110V or 220V AC) to ~0-1000V DC @ 10-100mA. I need several *variable/programmable* voltage and current sources in the same housing. Weight is a big issue but temperature/heat is not if within reason. These sources need to operate continuously.

The initial supply can actually be from DC by using a large transformer rather from mains if need be. Ripple is not a huge issue <

1-3%. Size is important but secondary to weight. The loads is mainly resistive but with with some capacitance probably less all less than 1nf.

I believe that any standard topology used for for standard microelectronics projects, if adaptable to the higher voltage, would work fine. I am drifting towards using a simple switching topology.

Seems like it would work fine if using igbts and give me the variability/probability I desire and somewhat lower in weight than an equivalent transformer based system.

Also, of course is the standard

.

Again, regulation is not necessarily an issue as I can do it before the power supply so a simple linear attenuation could work, at least for prototyping. Switchers seem to be the way to go though. My question is, would it be difficult to adapt such topologies to the voltages I require? As far as I can tell I would just have to find the rated components? Is this correct?

Thanks, James

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This is better...

Version 4

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I Agree.

What do you think, some brute force C across R5?

Something like this ought to work...

Where R3 may not be needed if R5 is fairly big.

Maybe a diode or zener across R5 too, in case the load arcs or something, to protect the opamp.

John

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That\'s all well and good, but you need to specify precisely what you
want instead of just spouting generalities.

4.5GV ?

With spice I can deal with that everyday, but is that really GV? I can think of MV, but GV... What was that?

-- Thanks, Fred.

"James Rollins" a écrit dans le message de news: snipped-for-privacy@w40g2000yqd.googlegroups.com...

Uh, how can this have been granted a patent?

Is the next step patenting a two stages resistor divider? Well, no it can't now. I've just made it public domain...

-- Thanks, Fred.

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The LM1117 won\'t work in there because it can\'t supply the 1.5A the
supply needs under full load (1kV, 10mA).

Works in real life, or in simulation? Your model ignores any dynamics inside the F10. And that opamp may not be able to drive the base of the NPN... 1.5 amps, beta 20, needs 75 mA of base current. The LT is only good for a few mA.

John

snipped-for-privacy@a7g2000yqk.googlegroups.com...

It was an ultrarelativistic synchrotron, SPEAR by name. Basically a vacuum tube with a bunch of trapped electrons (positive electrons, usually) going in circles.

Individual kinetic energy of the positrons was routinely set at 4.5 GeV, there weren't actually any static fields that were creating such a large potential difference.

The power supply was a two-mile-long linear accelerator... strung out collections of megawatt power klystrons... like I say, exotic. The best part was the safety orientation, all about the various safety features (4 foot concrete for radiation shielding; alarms for: hydrogen leaks, earthquake, and radiation; interlocks that could shutdown the whole two-mile linear accelerator if your doors weren't shut).