5kV 40uA from 120VAC

Ya gotz yer AC, and ya gotz yer DC.

Then we gotz retarded twitz like you.

Go back to your TV and your Big Time Wrestling viewing sessions. You are stinkin' up the place here.

Dingledorf. I am talking about the Power Supply efficiency, not the light bulb topology.

Jeez, try to keep up, ya dope. This is a POWER SUPPLY thread.

A 5kV 40uA HVPS requires next to no input power. A VERY small number.

So to power it via 120V AC means it will be a very low consumer, and nothing to fuss over as far as a "spec" goes. I even properly recommended a dongle and provided a supply schematic that is DC fed.

My remark simply states that if it is NOT very efficient, it will be heating up, and will likely be a fire hazard. Should not have been that hard to discern.

So, IF someone designed a proper, slightly more costly on parts supply for a CFL, it would not only be more efficient than they already are, it would last longer due to a supply that did not burn out before the tube did.

How small?

John

Come on, John! You're asking DimBulb a question that requires a numeric answer. That's hitting below the belt. You might just as well ask him what the opamp does.

It will take a dongle that can push a 313 milliwatt load, if one considers the supply to operate at 64% efficiency.

That yields the 200 milliwatts that such a supply would push.

OK, but it wouldn't shock me if the efficiency was much lower. I think (correct me if I'm wrong) that the output stage is a sinewave ocillator, so it might be as bad as 25% efficient. And it's fronted by a linear regulator, which might be, say, 50%, depending. So overall efficiency could be in the 12% ballpark, maybe less.

Did you measure it?

John

It would me.

Huh?

You are thinking of POWER applications. Low power HV supplies typically have higher efficiencies.

That would be way off. I do not have a single supply in my portfolio that uses nearly ten times what it puts out. Even on the LV side.

A long time ago, yes. Like '96ish.

We have made HV supplies that were 86% efficient.

Customers want their HV pulse, and they want it for months, not minutes or hours. (that was an air freshener piezo supply that we made BEFORE the current market devices hit the channel.

Well, is it a sinewave oscillator? I'd be surprised if the output section was as good as 25% efficient.

A linear regulator is no more efficient than Vout/Vin, and in practise usually less. It doesn't matter if it's microwatts or kilowatts. And its efficiency is multiplied by the efficiency of the following oscillator-multiplier stage. 50% * 25% = 12.5%

Portfolio? Show us some more.

Measure it again.

John

You ain't real bright then.

I have a 28kV supply that IS used every day in a medical high resolution X-ray monochrome display. It provides the anode and G2 and is pretty efficient at full load and even more so at no load and low load. It certainly isn't 12.5%

You want numbers? It runs on 15 Volts. It uses 0.8 amps unloaded.

That's what... 12 Watts. But 28kV @ 0 Amps is zero load, right? Except that there is a load. There is a trickle to zero resistor in there so it does not retain a charged HV cap after being powered off. And there is some capacitive losses to the chassis, and a few other little efficiency bandits, but not much.

That is when it is tuned correctly, and they all got tuned correctly.

This is a commercial supply for a major manufacturer, and was a limited run for an already out of life cycle product.

Under full load, it uses 2.2 Amps when loaded to 60% of it's rating. That is 33 Watts in. It uses 44 Watts at full load for 34% efficiency.

I did not even factor in the G2 supply, so it is actually slightly more efficient than these numbers.

That is 16.8 Watts at the output for 51% in/out efficiency. It would be slightly less efficient at full load (28 Watts).

It makes 28kV @ 1mA. The numbers I gave for 'loaded' are for 0.6mA and for full load driving at 1mA.

No shit. That applies to the entire supply. Efficiency is power out over power in.

Maybe you never tuned your circuits.

mkayyyy. So you've never tuned a circuit for resonance?

You probably did not even look at the log amp yet, or I would have heard about it, and I posted that nearly a couple weeks ago.

Why? You should re-hash your circuits (or mentality). So, it probably isn't as high as 64%, but I have built them. I am quite sure it isn't 12%.

Did you build the circuit or something?

Don't forget to gap the transformer core. Probably 1 or 2 mils.

The transformer is quite small too. You have to place tapes between each secondary layer as you build it up to the final turns count.

At below say 1.5kV, you can vacuum impregnate the transformer and conformal coat the circuit board after assembly, and not even have to pot it.

Above that voltage, the whole thing should get potted, and testing should take place in a bath of Fluorinert prior to that.

Final bath in a hot, brominated solvent (Ensolve), and bake for 10 minutes @ 60°C, just prior to potting in freshly mixed General Electric RTV potting compound(dang name slips me mind). Place that in the vacuum chamber and evacuate all the air from the potting compound, and all the air from the PCB, then release, and place in curing oven at 60°C for about 45 minutes, and they'll be ready to test 'hot'.

efficient

what

Your innumeracy is showing again. All power supplies are 0% efficient at no load.

That's zero per cent efficiency.

John

You're an idiot.

Great technical response, dimthing.

Like him claiming it would be a mere 1% efficient was 'technical'.

You are also an idiot. Already knew that though.

Find something else to f*ck up in that trailer. Stop stalking me in Usenet, like a little twit waiting to get the shit knocked out of him. Cause I'll oblige you, little twit.

His estimate is probably correct because he has a great deal of experience. It is obvious by your comments that you have little.

You are welcome to try.

Do the math.

John

It doesn't take experience, it just takes a tiny bit of math. You don't even need a calculator.

John

I know, John. The reply was to talk down to the incompetent.

I doubt it. HV Power supplies are a niche. Johnny doesn't niche well.

It is MY supply, idiot.