24V switching PSU?

Assuming it's an incandescent lamp, it will be considerably brighter and have a much shorter life under those conditions than when powered by 120VAC.

If it had a constant resistance of 144 ohms it would dissipate about

Or to put it another way, the diode reduces the RMS voltage from 240V to about 169V (240/sqrt(2))

Best regards, Spehro Pefhany

Now that's more like it. Thanks

I can believe it, now. Today I held in my hand a 1000W RMS amplifier that was less than half the size of a PC PSU. Cost around $400.

I read in sci.electronics.design that Dirk Bruere at Neopax wrote (in ) about '24V switching PSU?', on Thu, 13 Oct 2005:

No, you didn't. Watts are NEVER RMS; RMS is a property of 'field quantities' such as voltage and current.

Music business. It is capable of putting out sufficient current at sufficient voltage to continuously dissipate 1kW of heat into the load environment.

Not really. It simply means that it is not measured as a peak or intermittant power output.

Again, they are meaningful descriptions. Continuous Watts could refer to peak values of spike trains. RMS Watts could refer to ten second bursts before the overload protection cuts in or the amp bursts into flames. Continuous RMS Watts eliminates both those possibilities. Ask a lawyer.

From Powersoft ? I have one back in the office too.

Graham

That's it. Amazing! (coming from a non-analogue background) I had considered using it as a motor controller.

Assuming a couple of big diodes across the output, why?

I read in sci.electronics.design that Spehro Pefhany wrote (in ) about '24V switching PSU?', on Thu, 13 Oct 2005:

You know why.

intermittant

Ah, that figures. Lawyers know all about "RMS watts" (or are they really "RMS Watts") and "continuous RMS watts" (Continuous RMS Watts?). I wonder of lawyers designed the amplifiers too.

Are you a lawyer?

intermittant

cuts

I certainly *hope* not! Though every time Windows crashes makes me think you have a point.

As others have pointed out, "RMS watts" (no capital 'W') is meaningless.

Damn, I don't know. Probably for the same reason you shouldn't mix weights of motor oil. :-)

It's something about they'll interact with each other - but, as usual, somebody smarter than I am will have to field this one.

Thanks, Rich

intermittant

cuts

No, I ANAL. ;-P

Thank you. I'm glad we've finally got this settled. :-)

Thanks, Rich

intermittant

No, but lawyers look at things the way programmers do.

Why use diodes on a 12-0-12 config?

Because the foldover currents will certainly be unmatched. That being so, when shorted (or overloaded) one PSU will get -12V applied across its terminals. This may well be bad for it. I was assuming that it was a 24V supply, not a 12V center tapped supply. In any case, in some cases with motors, and fast reversing, the motor can impose a negative voltage across the supply.