Regulated power supply

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I need a simple regulated sym. powersupply with an output of 20VDC to 90DCV (variable)and the current must be 10A RMS and 20A MAX.
Something like from www.thel.de
 

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paulb said:
I looked at that website and could not find the supply you are describing. Are you sure about the specs? Why do you need a variable voltage, over such a wide range, for an amplifier?
When you have a toroid of let us say 2x60VAC and you want to build an amplifier that only needs 2x25VDC you can use this regulator without changing the toroid.And another thing is you don't need a large bank of caps maybe half the amount.If you want I can make a translation for you because its in German
http://www.thel-audioworld.de/module/spr/spr10.htm
 
meanman1964 said:

When you have a toroid of let us say 2x60VAC and you want to build an amplifier that only needs 2x25VDC you can use this regulator without changing the toroid.And another thing is you don't need a large bank of caps maybe half the amount.If you want I can make a translation for you because its in German
http://www.thel-audioworld.de/module/spr/spr10.htm
that's odd logic for amp testing.
20Adc from 60Vac needs 2400VA per winding. That means you are planning a 5kVA transformer for a variable supply. In my opinion, bonkers to go down this route.
 
The regulator has to dissipate whatever power the amp doesn't use. If you have a 60VAC transformer the caps will charge to about 80VDC or so. IF you are going to set the regulator for 25VDC out, the regulator will be dropping 80-25 = 55V. At 10A, the regulator will be dissipating 55V x 10A = 550W. That's one side of a bipolar power supply. Double that figure for a bipolar supply. It looks pretty bad...

However, an amp with a 25V bipolar supply (50V rail to rail) can put out a maximum of 18Vrms. 18V into a 4 Ohm load drives a little over 4.5 A through the speaker, each side of the supply contributes 2.25A, so it isn't quite as bad a the numbers above make it look, but you're still going to have to dissipate over 200W and that takes a BIG heatsink or a sort of big heatsink with a fan.

If you're building one amp, then get/build a PS to meet the required specs of that amp. It will be much smaller and cheaper.

If you plan to build and test a lot of different amps at different power levels then it makes sense to use a variable supply, in which case you want to built it up so it is capable of driving anything you connect to it- use huge heatsinks with fans.

Is regulation necessary?

I_F
 
The regulator you could buy at Thel Audio is designed special for audioamplifiers.They also say that toroids and a bank of caps always sound better than a regulated supply.Pure theoretical a stabilised supply is better but with several impulses you get overshooting.Their solution is by building regulator that isn' so exact.They tolerate a voltage drop of 40mV/Amp.And because the regulator has big output-impedanz you could use big caps and so you have a big stable impulse voltage.That's the main goal.
 
Fanuc said:
Hello,

Can you decipher any of the specifications of the regulator.?

Does it have DC offset protection ?

Noise, PSRR, etc

Thanks

Kevin


Hi Kevin,
Here are some specs:Input voltage 100VDC-Regulated outputvoltage 10V to 90VDC-Outputcurrent 10A RMS and 20A Max
Electronic energy dissipation delimitation-Short circuit proof
For a symmetrical operating voltage you need a positive and negative regulator.
 
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