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Hi,
Can PSUD 2 be programmed to show results of paralleled rectifiers, like two 5U4s, or two 5R4s ?
If so, exactly how does one go about getting that capability, and programing it into the PSUD model?
Thanks, having lotsa fun.
Jeff Medwin
Follow Ups:
Hello,
This was just wonderful, VERY appreciated, from each and every one of you.
Now, WHAT can get concocted ??? !!! Oh boy.
Thank you very much.
Jeff
I’ll calculate Vlaw and Vfac for a 5U4 tube with both its sections in parallel at 150mA (75mA per section). Look up the data sheet for the tube you want. You’ll need the data sheet to have the voltage drop versus plate current curve. You need to pick two points that are on either side of your planned current draw. Looking at the 5U4 data sheet:
http://www.mif.pg.gda.pl/homepages/frank/sheets/093/5/5U4GB.pdf
We see that the voltage drop curve is for EACH section. Therefore, we need to pick a point on either side of 75mA because the paralleled sections will be carrying half the current. I picked 50mA (100mA) and 150mA (300mA) as my points. We can see EACH section will drop 16.67V @ 50mA and 33.5V @ 150mA.
Now we need to use the current law equation to solve for both points in a simultaneous equation.
Ia=1000*Vfac*(V^Vlaw)
Where Ia is the current in mA and V is the drop of voltage in volts. Let’s now take the logarithms of that equation. It becomes:
Log(Ia)=Log(1000)+Log(Vfac)+Vlaw*Log(V)
Substituting the values we took from the data sheet on the equation, we will find:
Log(50mA)=Log(1000)+Log(Vfac)+Vlaw*Log(16.67V)
And
Log(150mA)=Log(1000)+Log(Vfac)+Vlaw*Log(33.5V)
Calculating the logarithms of the known amounts and adding them together, we will reach the following system of equations.
Log(Vfac)+Vlaw*Log(16.67)=Log(50/1000)
Log(Vfac)+Vlaw*Log(33.5)=Log(150/1000)
Log(Vfac)+1.2219Vlaw =-1.3010
Log(Vfac)+1.5250Vlaw =-0.8239
-0.3031Vlaw = -0.47709
Vlaw=1.5740
Substituting the value of Vlaw back into one of our equations we can determine Vfac.
Log(Vfac) +1.2219*1.5740 = -1.3010
Log(Vfac) +1.9233 = -1.3010
Log(Vfac) = -3.2243, using the Windows calculator Inv log function we find Vfac
Vfac = 0.0005966, or 5.966E-04
So, in your PSUDII rectifier text file the input parameters for your parallel 5U4 rectifier should be:
*Name Type DRes Vlaw Vfac Vpiv Ipks Ipkr
5U4_parallel, VT, 0.000,1.5740, 0.0005966, 1550, 99, 1.0
Now you should be able to calculate the Vlaw and Vfac for any type of rectifier you want to model.
Rgs, JLH
.
Thanks John!
----------------
"When Khruschev said "we will bury you" I don't think he meant with surplus parts." zacster
If you go here http://www.duncanamps.com/psud2/rect_list.php there is a link that says "Click here to download a rectifiers.txt file based on the models below." This will download a rectifiers.txt file that has tons of additional rectifier models, including dual 5U4's and dual 5R4's -- in fact, several different versions of the dual 5U4. Just replace the file you already have (as mentioned, probably saved in C:\Program Files\Duncan Amplification\Power Supply Designer 2) with the new one.
nt
You can build your own rectifier. Just give it half as much characteristic resistance, twice the rating, li'dat.
Haven't done it, so don't ask for button pushes, but it's there, and I think there's help stuff, forum, other resources.
Aloha,
Poinz
AudioTropic
Can anyone point me to a PSUD Forum, or user resources ?? Thanks.
Jeff
Nav to PSUD; it's in there somewhere. I looked in a couple of times. Good folks.
P
You can edit the rectifiers.txt file to use whatever parameters you want.
Hey! Hey! That is great news.
Another question, can members with patience, spoon-feed a computer challenged person (that's me), step by step, on how access that file, and go from, say, one 5U4GB to two in parallel??
I need to see this.
If so, I would be very grateful for such help.
Thanks in advance,
Jeff Medwin
Hi Jeff,
The file containing rectifier specs is called RECTIFIERS.TXT and can be found in whatever directory you used for PSUD (likely PROGRAM FILES > DUNCAN AMPLIFICATION > POWER SUPPLY DESIGNER 2).
RECTIFIERS.TXT is an ASCII text file and can be edited using Microsoft Notepad. It begins with the following lines (note that a line beginning with * is a comment line):
*
* RECTIFIERS.TXT V2.1 02/06/2003
*
* This file contains the parameters used for various types of
* rectifier. You may hand amend this file if you wish, in order
* to introduce new types of rectifier.
*
* Should you wish to add your own rectifiers, please refer to
* the technical section in the help file.
*
* The format is:
*
* Name,Type,Dres,Vlaw,Vfac,Vpiv,Ipks,Ipkr
*
* Type: SS (Solid state) or VT (Vacuum tube).
* Dres: Internal resistance of diode
* Vlaw: Va/Ia power law
* Vfac: Va/Ia factor
* Vpiv: Peak Inverse Voltage allowed
* Ipks: Peak current allowed, single cycle (Amps)
* Ipkr: Peak current allowed, repetitive (Amps)
*
Further down are the lines that specifiy VT rectifiers, as follows:
* Vacuum tube rectifiers
*Name Type DRes Vlaw Vfac Vpiv Ipks Ipkr
5AR4, VT, 0.000,1.5, 0.00396, 1500, 99, 0.75
5R4-G, VT, 0.000,1.5, 0.00046, 2800, 99, 0.65
5R4-GY, VT, 0.000,1.5, 0.00046, 2800, 99, 0.65
5R4-GYA, VT, 0.000,1.5, 0.00046, 2800, 99, 0.65
5R4-GYB, VT, 0.000,1.5, 0.00050, 3100, 99, 0.715
5U4-G, VT, 0.000,1.5, 0.00078, 1550, 99, 0.8
5U4-GA, VT, 0.000,1.5, 0.00078, 1550, 99, 0.9
5U4-GB, VT, 0.000,1.5, 0.000755,1550, 99, 1.0
5V3-A, VT, 0.000,1.5, 0.001287,1550, 6.6, 1.4
5V4-G, VT, 0.000,1.263, 0.00273, 1400, 99, 0.525
5V4-GA, VT, 0.000,1.263, 0.00273, 1400, 99, 0.525
5Y3-G, VT, 0.000,1.5, 0.000269,1400, 2.2, 0.375
5Y3-GA, VT, 0.000,1.5, 0.000269,1400, 2.2, 0.44
5Y3-GT, VT, 0.000,1.5, 0.000354,1400, 2.2, 0.44
5Z3, VT, 0.000,1.5, 0.00051, 1550, 99, 0.675
6AU4-GT, VT, 0.000,1.5, 0.0028, 4500, 99, 1.05
6AX4-GT, VT, 0.000,1.5, 0.0014, 4400, 99, 0.825
6AX4-GTA, VT, 0.000,1.5, 0.0014, 4400, 99, 1.0
6AX4-GTB, VT, 0.000,1.5, 0.0014, 5000, 99, 1.0
6CA4, VT, 0.000,1.5, 0.002, 1300, 1.8, 0.5
6D22S, VT, 0.000,1.2646, 0.00677, 5000, 99, 99
6DE4, VT, 0.000,1.5, 0.00193, 5500, 99, 1.1
6X4, VT, 0.000,1.5, 0.00068, 1250, 99, 0.245
6X5, VT, 0.000,1.5, 0.00134, 1250, 99, 0.245
6X5-GT, VT, 0.000,1.5, 0.00068, 1250, 99, 0.245
6W4-GT, VT, 0.000,1.5, 0.0026, 3850, 99, 0.75
83, VT, 0.000,20, 1E-25, 1550, 99, 1.0
EZ80, VT, 0.000,1.5, 0.00068, 1250, 99, 0.245
EZ81, VT, 0.000,1.5, 0.002, 1300, 1.8, 0.5
GZ33, VT, 0.000,1.415, 0.004334,1400, 99, 99
GZ34, VT, 0.000,1.5, 0.00396, 1500, 99, 0.75
GZ37, VT, 0.000,1.35, 0.001409,1600, 99, 0.75
***** END OF FILE
It seems to me that you would be advised to save the file under a different name (e.g.RECTIFIERX.TXT) before making changes, so you can revert to the original if necessary.
Since all rectifier types seem to have a DRes of 0.000, that can't be the parameter to alter to simulate 2 tubes in parallel. Vfac seems to be the one you're interested in. Anyway, best of luck!
Keep usosted.
You da bomb.
P
I did a good bit of research on the cap impedance question and the answer generally is that for electr0holytic caps @60hz or so for 50uf or so down to 20uf the question is yes 2ohms or so... lowz about 1ohm....so thanks for prompting me....lytics are definitely not linear...
film are likely higher actually.. but maybe more linear...
-3db
I saw data sheets on the GE 97F motor run caps online recently, looking at ranges between 10uF - 50uF where most were about 29 mohms, and for the CDE unilytic and Mundorf M Tube caps as low as 9 mohms depending on value.
Yes, Thanks for the synopsis.
How in the heck do we look at DOUBLED up rectifiers ..... is what we need to see next. I have heard doubled up rectifiers, want to simulate it, 'am substantially computer challenged.
Hey, why don't we swap PSUD graphs privately, to see if we can improve each other's implementations?? Two heads better than one.
Send me a screen shot of yours, and I will do vice versa.
Are you using filters with three Ls? If so, I figured out how to do it with one less L/C than most seem to use, and it should sound better. (It did so when I compared this, listening-wise, a couple years back.)
Jeff
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