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Old 13th August 2013, 05:13 PM   #1221
stajo is offline stajo  Sweden
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By setting delay and measuring time you can "zoom" into the startup phase to look for if the caps are sucking energy from the transformer that starts ringings.

I dont see any such tendencies here. Of course this has to do with many factors like the speed and size of caps etc. Inductors in the filter chain can also start interfere with caps and trannys in a bad way to show this edgy behaviour under startup.

Snubbers can be good but its very hard to test them out. There is no "one size fits all" value there. So if you cant test them out leave them out. They can certainly cause more harm then good.
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Old 13th August 2013, 05:21 PM   #1222
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I ont' understand why the voltage at the load varies depending the ms and the delay?
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Old 13th August 2013, 05:30 PM   #1223
stajo is offline stajo  Sweden
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Quote:
Originally Posted by merlin el mago View Post
I ont' understand why the voltage at the load varies depending the ms and the delay?
I presume that you by "voltage at the load" meen V(I1) in this case. It shows minimum value and maximum value over the voltage over load (I1). Third column "Diff" is "Max minus Min voltage over load".

If you set the measurment with a delay long enough so caps has charged and startup phase is over then "Diff" is "ripple under run".

If you set it with no delay "Diff" is "Zero to Max voltage" which is not very interesting if youre looking for ripple.

Does that make sense?
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Old 13th August 2013, 05:39 PM   #1224
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Yes I wanna say V(l1) as voltage at the load.

Diff is only ripple at the start up or is continous ripple when run?
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Old 13th August 2013, 06:07 PM   #1225
stajo is offline stajo  Sweden
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I made some pix for you. Maybe those say more then words. Look at measured time and delay at every picture and how the curves and measures change.

Its all the same circuit, just different measuring time and delay.
Attached Images
File Type: png psudVIPh4.png (113.2 KB, 78 views)
File Type: png psudVIPh5.png (90.4 KB, 70 views)
File Type: png psudVIPh6.png (98.7 KB, 69 views)
File Type: png psudVIPh7.png (111.7 KB, 67 views)
File Type: png psudVIPh8.png (114.8 KB, 21 views)
File Type: png psudVIPh9.png (109.4 KB, 21 views)
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Old 13th August 2013, 06:21 PM   #1226
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Thanks for your work
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Old 13th August 2013, 06:46 PM   #1227
RCruz is offline RCruz  Switzerland
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Hi Merlin

I remember you placed some small caps in the inputs of your itch... why ?
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Old 13th August 2013, 06:47 PM   #1228
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10nF between signal an ground to avoid antenna efect caused by the cables.
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Old 13th August 2013, 06:50 PM   #1229
Salas is online now Salas  Greece
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Maybe between RCA ring and chassis?
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Old 13th August 2013, 06:59 PM   #1230
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Actually I don't have any cap connected because the Itch runs dead like a tomb
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