?? DIY PS Audio Humbuster

[Richard C]

Paulmc, I understand your diagram very well and it is exactly this arrangement I have been refering to all along.

Clearly for pure DC anything less than +/- 1V cannot pass through but we're not really talking about DC, the only way of seeing DC on an AC waveform is by integrating it.

The point I'm trying to make is that if you apply AC with an offset (the reality), this diode arrangement won't have much effect except for reducing the ampitude of both halves of the waveform by two diode drops, it can't possibly remove the offset because the diodes directly couple the input to the output.

[millwood]

Originally posted by Richard C
The point I'm trying to make is that if you apply AC with an offset (the reality), this diode arrangement won't have much effect except for reducing the ampitude of both halves of the waveform by two diode drops, it can't possibly remove the offset because the diodes directly couple the input to the output.

an A/C with offset is the same as a DC + A/c with no offset.

The cap will function the same in either situation. and diode really doesn't do anything here in terms of removing A/C.

[Richard C]

Originally posted by millwood


an A/C with offset is the same as a DC + A/c with no offset.

The cap will function the same in either situation. and diode really doesn't do anything here in terms of removing A/C.

Paulmc seems to be thinking of simple DC rather than DC which is riding on the back of much larger AC.

The key components in a DC blocker are the capacitors which should be large so that they present a low impedance at mains frequencies, the diodes should rarely conduct if at all.

The claims for the Humbuster state that it's the diodes that remove the DC and this is what puzzled me about it. The capacitors appear to be several thousand times too small to be effective.

[ChocoHolic]

Hi!
I also thought that the caps are the key components and the diodes are used to clamp the max voltage across the cap.
...which is in heavy mismatch to the statement of paulmc...

On the other hand paulmc gave the technical details of his product
and tried to convey how it works. His behaviour does not look like someone who sells expensive but effectless circuits...

Hm, do we miss out something?
..may be some interaction with the nonlinear inductive
transformer load...?
Anybody out there who tried it?
My mains supply has nearly no Offset, so I cannot test it (less than 5mV, measured behind a passive filter of 200k and 5x10uF MKT, which reduces the AC component to some millivolts and overdrive of DMM is no issue)....

My two fat 1kVA torroids make some noise, not matter if I put 100.000 uF in series or not. Their noise is definitely not related to DC saturation.....

Bye
Markus

[SmarmyDog]

Perhaps the brief dead time that occurs during the zero-crossing when no diodes are conducting is long enough in duration to allow the core to reset (or at least get much closer to resetting) so that any cumulative bias is reduced or eliminated. Using two diode drops could be the minimum dead-band for a noticeable improvement.

Yes, it is quite possible I have no idea what I just said, but I’m gonna stick my name under it anyway…

-Casey Walsh

[klonius]

Does anyone have a full schematic for diy humbuster?

[Ulisez]

Originally Posted by klonius

Does anyone have a full schematic for diy humbuster?

Yep that would be great.

[Mooly]

They all use the same technique... project here
Mains DC and Transformers

[CCD]

Hello All.

@ paulmc

you have Schematics?

CCD