Power Transformer Rating

101.78.181.154

Posted on May 20, 2016 at 02:58:44

Tubenstein
Audiophile

Posts: 251
Joined: August 5, 2011

Hello!
Which one is more adequate for following? 650vct @100mA or 300vct @100mA?

Power transformer => 2 x 6D22S (full wave rectification) => LC Choke (16H 11.2 ohm DCR) => 100uf => Choke (40H 100 ohm DCR) => 100uf => 260vdc => K and K Audio HV regulator => 180vdc B+

Thanks!

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WOW...16 Henry...11.2 ohms!... I thought I used good chokes-nT

Cleantimestream

08:27:31 05/20/16

RE: Power Transformer Rating, posted on May 20, 2016 at 05:13:54
Chip647 Audiophile Posts: 2652 Location: The South Joined: December 24, 2012	The voltage rating is end to end on the secondary. a "650 vct" transformer is 325-0-325 (zero is the center tap) which will give you roughly 6500.71 = 460 volts DC at the first filter. If the other "300" vct is really 150-0-150 then you will get 300 0.71 or around 213 volts DC. What are you shooting for?

WOW...16 Henry...11.2 ohms!... I thought I used good chokes-nT, posted on May 20, 2016 at 08:27:31
Cleantimestream Audiophile Posts: 7551 Location: Kentucky Joined: June 30, 2005	! The Mind has No Firewall~ U.S. Army War College.

RE: Power Transformer Rating, posted on May 20, 2016 at 09:49:33
Steve O Audiophile Posts: 12383 Location: SE MI Joined: September 6, 2001	Actually, I do believe you'll get the voltages quoted assuming FW/CT, cap input filter and ignore rectifier and other losses. (650/2)*1.414~460. He combined steps in the basic math.

RE: Power Transformer Rating, posted on May 20, 2016 at 10:01:03
JKT Audiophile Posts: 612 Location: Midwest Joined: November 26, 2002	I believe the OP specified a choke input PS. 325Vrms times 0.9 equals about 290Vdc. Add the losses in the second choke and you are close to 260V. My question is: If you are using CCS fed shunt reg. why the second LC filter? "It is better to remain silent and thought a fool, then speak and remove all doubt." A. Lincoln

RE: Power Transformer Rating, posted on May 20, 2016 at 10:08:20
Tre' Industry Professional Posts: 17302 Location: So. Cal. Joined: February 9, 2002	"He combined steps in the basic math." I see that now. But it's a choke input filter. BTW I fixed my math. Half of the end to end voltage times .9, minus losses. Tre' Have Fun and Enjoy the Music "Still Working the Problem"

RE: Power Transformer Rating, posted on May 20, 2016 at 10:41:42
Steve O Audiophile Posts: 12383 Location: SE MI Joined: September 6, 2001	L input, I see that now. That's why I state my assumptions...even if I'm wrong.

RE: Power Transformer Rating, posted on May 21, 2016 at 15:16:33
Tubenstein Audiophile Posts: 251 Joined: August 5, 2011	My target is 200vdc, sounds like the 300vct @100mA is more adequate, right? How about this one? 300vct @100mA => 6D22S (2 for full wave) => 16H 11.2 ohm LC Choke => 200uf => 200vdc Thanks!

RE: Power Transformer Rating, posted on May 21, 2016 at 17:08:11
Steve O Audiophile Posts: 12383 Location: SE MI Joined: September 6, 2001	Do you think 6D22s can handle 200uF. Typically data regarding max capv vs impedance for damper tubes is scarce so I'd think erring on the safe side would be prudent. 200uF seems high.

RE: Power Transformer Rating, posted on May 21, 2016 at 17:38:54
Tre' Industry Professional Posts: 17302 Location: So. Cal. Joined: February 9, 2002	I'm sorry. That was a typo. I meant to type 20uf. Interestingly PSUD2 doesn't throw a warning with 6D22s and a 200uf input cap. Tre' Have Fun and Enjoy the Music "Still Working the Problem"

RE: Power Transformer Rating, posted on May 22, 2016 at 01:27:57
Tubenstein Audiophile Posts: 251 Joined: August 5, 2011	How about this one? 600vct @100mA => 6CJ3 (2 for full wave) => 16H 11.2 ohm LC Choke => 200uf => K&K Audio HV regulator => 200vdc Is that ok? Can you determine the DCR of the power transformer (600vct @100mA) for me? Thanks!

RE: Power Transformer Rating, posted on May 22, 2016 at 07:14:27
Tre' Industry Professional Posts: 17302 Location: So. Cal. Joined: February 9, 2002	That would give about 260vdc after the choke. I have no way of knowing the DCR of your transformer. Do you have a ohm meter? Tre' Have Fun and Enjoy the Music "Still Working the Problem"

RE: Power Transformer Rating, posted on May 22, 2016 at 07:41:40
Tubenstein Audiophile Posts: 251 Joined: August 5, 2011	I want to build another power supply to compare how it sounds. Like this: 600vct @100mA => 6D22S => 16H 11.2 ohm LC Choke => 5000uf => 5W RESISTOR => 5000uf => 2W RESISTOR => 5000uf => 180vdc Would you please show me which value of both 5W and 2W resistors to achieve the value at the end for 185vdc?? Thanks!

RE: Power Transformer Rating, posted on May 22, 2016 at 08:24:51
Tre' Industry Professional Posts: 17302 Location: So. Cal. Joined: February 9, 2002	No one can do that without knowing the DCR of the power transformer and the amount of current the circuit is going to draw. It's easier to just build it and change the values of the resistors until you get the voltage you want. Tre' Have Fun and Enjoy the Music "Still Working the Problem"

RE: Power Transformer Rating, posted on May 22, 2016 at 10:27:16
Tubenstein Audiophile Posts: 251 Joined: August 5, 2011	So the DC voltage still 260v after the LC choke, right?

RE: Power Transformer Rating, posted on May 22, 2016 at 12:13:40
Tre' Industry Professional Posts: 17302 Location: So. Cal. Joined: February 9, 2002	Yes. It should be something close to that. Tre' Have Fun and Enjoy the Music "Still Working the Problem"

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Power Transformer Rating

101.78.181.154