A can confirm that what dimkasta is reporting is the sound of the toroid, not the electrolyics. It's the same as what I found.
Electrolytics breaking in is harder to pin down. It goes something like this: for the first few hours things are crazy sounding, really loose and sloppy, but also really intense. Then suddenly things go dead and gummed up, and then, over a period of days, of if you really listen closely, weeks or longer, they start to open out, becoming basically clear and transparent.
Electrolytics breaking in is harder to pin down. It goes something like this: for the first few hours things are crazy sounding, really loose and sloppy, but also really intense. Then suddenly things go dead and gummed up, and then, over a period of days, of if you really listen closely, weeks or longer, they start to open out, becoming basically clear and transparent.
i'm running a single 100va Antek - AN-1212 and feel that it's more than adequate . it sounds fantastic .
cheers Woody
cheers Woody
Ok just found out something a bit terrifying. The damn mounting screw going through the toroid actually acts as a single wire open secondary.
And since my case was earthed through the shafner iec socket/filter, there was some current going to earth. Lifting the earth, I measured 14v on the bolt and the normal secondary voltage went back to around 13,4 as expected....
That is probably why it was blowing the fuse too...
Excuse me for yelling but...
WHY THE HELL DO MANUFACTURERS USE METAL MOUNTING SCREWS....???????
Guys how do you mount yours? I m thinking to use some kind of plastic screw or use sth to glue it on the metal plate and then screw the plate on the chassis
And since my case was earthed through the shafner iec socket/filter, there was some current going to earth. Lifting the earth, I measured 14v on the bolt and the normal secondary voltage went back to around 13,4 as expected....
That is probably why it was blowing the fuse too...
Excuse me for yelling but...
WHY THE HELL DO MANUFACTURERS USE METAL MOUNTING SCREWS....???????
Guys how do you mount yours? I m thinking to use some kind of plastic screw or use sth to glue it on the metal plate and then screw the plate on the chassis
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Think about it, that makes no sense: An open circuit can not have any current flow, by definition.
Hmmm...
Still, there is a voltage drop (from 13,4 to 12V) on the secondaries when I ground the chassis part where the transformer is mounted.
Leaving the transformer lying on the chassis (no screw) creates only 2V on the metal (compared to earth) and secondaries give 13,4V (even when I earth the chassis).
Using the screw again, increases the V on the chassis to 14 and earthing the metal results in the secondaries' V dropping to 12V.
Could be weak insulation that leaks between the wires when I squeeze the toroid by tightening the screw? But even then, this does not explain the V on the chassis and why earthing it increases the load on the toroid, dropping the V of the secondaries to their "under load" voltage....
Still, there is a voltage drop (from 13,4 to 12V) on the secondaries when I ground the chassis part where the transformer is mounted.
Leaving the transformer lying on the chassis (no screw) creates only 2V on the metal (compared to earth) and secondaries give 13,4V (even when I earth the chassis).
Using the screw again, increases the V on the chassis to 14 and earthing the metal results in the secondaries' V dropping to 12V.
Could be weak insulation that leaks between the wires when I squeeze the toroid by tightening the screw? But even then, this does not explain the V on the chassis and why earthing it increases the load on the toroid, dropping the V of the secondaries to their "under load" voltage....
Hard for me to understand why, if the chassis is grounded at the IEC socket (presumably also connected to the house ground), there should be any measurable voltage on the chassis. Ground loop perhaps, but voltage potential above what the chassis and wiring resistance would engender? hmmm. On filtered IECs, I thought the polarity of the caps would prohibit any "tension" on the bolt from doing anything but traveling to house ground.
In other words, are you sure there's a chassis connection to house ground?
Ohms law. Voltage = Current x Resistance.
If a metal object is "floating", that is the resistance to the reference point is "infinite", then it's easy enough to generate large and wildly fluctuating voltages by, for example, magnetic induction.
So yes, the voltage between earth and a floating chassis can be a few volts when the transformer is energized. That's why we earth the power supply chassis!
But it's not a problem, and would not influence the voltage across the secondary windings.
If a metal object is "floating", that is the resistance to the reference point is "infinite", then it's easy enough to generate large and wildly fluctuating voltages by, for example, magnetic induction.
So yes, the voltage between earth and a floating chassis can be a few volts when the transformer is energized. That's why we earth the power supply chassis!
But it's not a problem, and would not influence the voltage across the secondary windings.
I got some non-filtered IECs today and did some more testing.
It seems that the symptoms were a bit off, as was I in my investigation.
I measured all voltages today before and after the rectifiers and all was ok. Then I unplugged the psu and rubbed my hands at my success.... Only to plug it back a few minutes after and measure again 11V at the outputs...
What changed was the polarity of my wall cable...
Seems I probably fried the bridges (seems peculiar that both fried on the same side)? All diodes measure 0,4V at forward voltage drop with my dmm. Could be the reverse voltage breaking point droped below 12V?
Or GBPC602-E4/51 is just picky on how you connect the phase of the transformer?
Transformer outputs were around 12,4 AC
Probably explains the fuse blowing too?
It seems that the symptoms were a bit off, as was I in my investigation.
I measured all voltages today before and after the rectifiers and all was ok. Then I unplugged the psu and rubbed my hands at my success.... Only to plug it back a few minutes after and measure again 11V at the outputs...
What changed was the polarity of my wall cable...
Seems I probably fried the bridges (seems peculiar that both fried on the same side)? All diodes measure 0,4V at forward voltage drop with my dmm. Could be the reverse voltage breaking point droped below 12V?
Or GBPC602-E4/51 is just picky on how you connect the phase of the transformer?
Transformer outputs were around 12,4 AC
Probably explains the fuse blowing too?
@bucurb
VSPS300i and VSPS300m use the same BOM, it is downloaded from the web site, RJM Audio - Printed Circuit Boards. There is no practical difference in the boards.
If you need anything else, please email me.
@dimkasta
I've heard that some transformers are slightly sensitive to which side of the primary is wired hot, but it should not normally change the output voltage.
It would seem like your primary winding has a massive leakage to ground in one spot at the top of one of the coils. When that is wired cold, it's not a huge problem, when wired hot, it sucks considerable voltage from the primary, so the secondary voltage is down too.
I don't think it can be a problem with the bridges, its something on the primary side.
VSPS300i and VSPS300m use the same BOM, it is downloaded from the web site, RJM Audio - Printed Circuit Boards. There is no practical difference in the boards.
If you need anything else, please email me.
@dimkasta
I've heard that some transformers are slightly sensitive to which side of the primary is wired hot, but it should not normally change the output voltage.
It would seem like your primary winding has a massive leakage to ground in one spot at the top of one of the coils. When that is wired cold, it's not a huge problem, when wired hot, it sucks considerable voltage from the primary, so the secondary voltage is down too.
I don't think it can be a problem with the bridges, its something on the primary side.
I suspect that your transformer is bad. With no load your 12VA secondary should put out significantly more voltage than 12V or 14v AC. My 50VA torroid measures 17.5V with the Phonoclone connected. With the odd things going on I suspect you have a shorted winding somewhere. Does the transforer get warm at all?
17.5V with board connected is normal because of the caps circuit which gives a ~ x1.4 boost to the voltage.
The voltages I give are with nothing but the bridges connected.
Richard is probably right about the leakage on the primary. Although if wired correctly with the leakage in the end it should create no problem. I have left it connected for many hours and not heat was created on the transformer. Either with the leakage on the neutral side, or the phase side.
Anyway, I will contact mouser and request what is their policy on replacing such cases.
Thanks a lot for the support guys.
The voltages I give are with nothing but the bridges connected.
Richard is probably right about the leakage on the primary. Although if wired correctly with the leakage in the end it should create no problem. I have left it connected for many hours and not heat was created on the transformer. Either with the leakage on the neutral side, or the phase side.
Anyway, I will contact mouser and request what is their policy on replacing such cases.
Thanks a lot for the support guys.
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