Are such low values for Rs reasonable?
Yes, definitely. See post #5 by EUVL.
Mark, Michi124,
thanks for verification!
I already did the calculations with the same results. As it it these first time I use this experimental approach I was unsure of the value for Rs I got.
Regards,
Michael
thanks for verification!
I already did the calculations with the same results. As it it these first time I use this experimental approach I was unsure of the value for Rs I got.
Regards,
Michael
Audiomusica, since you doubt your experimental results from No-Math Quasimodo, you have no other choice than to use math for verification.
Your numerical values of fosc (6.25E+5) and Cx (1.0E-8) indicate that the secondary self inductance L is about (6.5E-6) Henrys. We calculate L using the LC resonance equation.
Plugging this value for L into equation (A.11) of the Quasimodo design note, we findThe LC resonance equation: 2 * Pi * fosc = 1 / sqrt(L * C)
Which seems to be in broad agreement with your experimental results. You were wrong to doubt them.R < 12.7 ohms
Mark, this is my result for AMGIS L01-6364, 2x115V / 2x18v / 25VA, and i am confuse because Cs is 3 time Cx and no 15 time like your recommendation,
CX: 0,22uF
CS: 0,68uF
RS: 11 Ohm
fosc ~ 60kHz
I have a very hard time to check and use the Math for verification, by any chance do you have an Excel were we can enter the values we found ( Cx, Cs, Fosc) with the result of RS....for Zeta=1
Just got the PCB today See post Quasimodo 4
CX: 0,22uF
CS: 0,68uF
RS: 11 Ohm
fosc ~ 60kHz
I have a very hard time to check and use the Math for verification, by any chance do you have an Excel were we can enter the values we found ( Cx, Cs, Fosc) with the result of RS....for Zeta=1
Just got the PCB today See post Quasimodo 4
Please honor the request of member JeffYoung who started this thread, and post Quasimodo results ONLY. Commentary, inquiries, requests, and general remarks can go to the general Quasimodo thread
Simple, no-math transformer snubber using Quasimodo test-jig
Simple, no-math transformer snubber using Quasimodo test-jig
Oops ...
After all this time, finally remembered to post my results over here.
Using Hammond 229D40 transformers acquired from Mouser
"My" chosen snubber values are:
0.15uF, 0.01uF and 424ohms (I have a BUNCH of 196 ohm and 226 ohm resistors so easily made my "424"ohm resistor, but that much accuracy is not needed )
mlloyd1
After all this time, finally remembered to post my results over here.
Using Hammond 229D40 transformers acquired from Mouser
"My" chosen snubber values are:
0.15uF, 0.01uF and 424ohms (I have a BUNCH of 196 ohm and 226 ohm resistors so easily made my "424"ohm resistor, but that much accuracy is not needed )
mlloyd1
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Audiophonics R-Core 230V primary dual 15V secondary 30VA, measurement with two secondaries in parallel
Cx 10nF
Cs 150nF
Rs 140Ω
I'm sorry is Selectronic not Audiophonics.
AnTek AS-3218
AnTek AS-3218 115v-18v
.01uF
.15uF
Primary shorted
1st secondary other shorted
10-12ohms
2nd secondary other shorted
10-12ohm
Both look pretty good, but I wrote 10R on the box for when I use it.
AnTek AS-3218 115v-18v
.01uF
.15uF
Primary shorted
1st secondary other shorted
10-12ohms
2nd secondary other shorted
10-12ohm
Both look pretty good, but I wrote 10R on the box for when I use it.
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