last used Duncanâ€™s PSU Help

Mike H · Post by **Mike H** » Mon Jan 16, 2012 4:30 pm

He's right, he's not wrong

So they're actually rectifying 390VAC, not 195, but using the CT to get 255VDC out as well.

colin.hepburn · Post by **colin.hepburn** » Mon Jan 16, 2012 4:52 pm

Right so I enter the 390v plus the primary and secondary winding resistance then

pre65 · Post by **pre65** » Mon Jan 16, 2012 5:00 pm

colin.hepburn wrote:Right so I enter the 390v plus the primary and secondary winding resistance then

If you are using a bridge rectifier-yes.

colin.hepburn · Post by **colin.hepburn** » Mon Jan 16, 2012 5:15 pm

Yep will be a bridge or maybe full wave needs big diodes thou

Mike H · Post by **Mike H** » Wed Jan 18, 2012 10:59 pm

Yeah but no but, if you use the full 195 - 0 - 195 on the bridge as 390, you're going to get a rectified DC of >500V. But you want 280V. I thought ...

Mike H · Post by **Mike H** » Wed Jan 18, 2012 11:01 pm

Which you ain't gonna get 'cause 195VAC will only get you 275VDC, no load.

So your 256VDC (still) looks about right to me, from that.

Mike H · Post by **Mike H** » Wed Jan 18, 2012 11:03 pm

Welcome to the world of trying to make stuff do what you want, but won't.

colin.hepburn · Post by **colin.hepburn** » Wed Jan 18, 2012 11:46 pm

Yep nothing ever works as you want it too
What I am thinking about is to build the posted 6P3s/ 6L6CT Schematic but a PSE version with the HT@280/300 with each 6p3s Bias at about 35/50mA so 144/204mA with 6n2p but also wanted to use a very stiff psu hence the Tor 300 195-0-195 @ 0.45mA again thinking the stuff psu would benefit the amp no voltage sag

Mike H · Post by **Mike H** » Thu Jan 19, 2012 12:18 am

Should be ideal yes, if you can put up with 256V

It'll work anyway.

colin.hepburn · Post by **colin.hepburn** » Mon Mar 05, 2012 7:19 pm

Hi All
When using Duncan's psu2
With a SS full wave rec to get a bit more voltage I tried just using C.LC.C no resistors to make the pi filter at the first cap just the 165R resistance of the Choke is this a good or bad way of doing it or will the psu be better if it is RC.LC .RC but at a lower voltage

Mike H · Post by **Mike H** » Tue Mar 06, 2012 1:22 pm

I'd leave the resistors out and just have CLC, the 165 choke DCR will help damp resonance, also the two C's ought not be identical values preferably

colin.hepburn · Post by **colin.hepburn** » Tue Mar 06, 2012 2:29 pm

OK thanks I was under the impression that the resistors helped the cap work better but at the expense of losing some voltage
I use a lower value first cap then choke and larger second and back to smaller value cap for the last one

Mike H · Post by **Mike H** » Wed Mar 07, 2012 2:53 pm

Added resistors will drop the Voltage yes, if that's what you want

Else added to a choke to improve damping of step response type resonances.

'ark at me, only know that cos Nick wrote it once.

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last used Duncanâ€™s PSU Help

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