Rectifier path of travel

[trem]

I am sorry I do not understand this, but can somebody explain the current flow through this rectifier? I see how the center tap connects to ground, but I do not see the negative to positive electron flow. I understand the instantaneous polarity of the transformer, but I do not understand the initial electron flow through the diodes. It almost seems like there should be another connection to ground for the electrons to get back through the diodes to the transformer.
Can one of you guys help me with this?
Thank You

http://www.ampwares.com/schematics/t...verb_ab763.pdf

[chipprogr]

im lost as well on this one..

[Enzo]

trem, without a link to a schematic, we have no idea which circuit you are asking about.

I will say in general, that in a power supply, the filter cap is part of the circuit. Not to mention currrent through the load. The cap is being charged with each cycle. SO perhaps that is the link you are missing?

[trem]

Can you supply a diagram, picture, drawing?
From the post, I do not have a clue what you said.
Just curious.

im lost as well on this one..

trem, without a link to a schematic, we have no idea which circuit you are asking about.

I will say in general, that in a power supply, the filter cap is part of the circuit. Not to mention currrent through the load. The cap is being charged with each cycle. SO perhaps that is the link you are missing?

1 - 2 - 3 strikes and I'm out.
Like this link perhaps??????
Sorry ....talk about a case of the Mondays

http://www.ampwares.com/schematics/t...verb_ab763.pdf

[JHow]

Are you asking about how the power supply is set up? (full-wave diode) I think there are many DC current paths to ground through the plates of the tubes to cathode, right?

[trem]

Hey Enzo -
So are you saying the path of travel is through the transformer CT, past the two caps in series via their ground, through the diodes and back to the PT ?
Thank You

[Enzo]

Yes.

Not quite that simple, but yes.

When the power is first applied, the empty caps must charge up. There is a current flow when this happens. Now assume the standby switch is open, so the high voltage is not connected to the rest of the circuit yet. Once that cap (two caps in series in the example) is fully charged, there won;t be any current flowing. Well a tiny bit through the bleeder resistors. Those are the 220k next to the caps. And an even tinier bit due to leakage in the caps. SO 460v over 440k - about 1ma steady current flow. That 1ma flows in the circuit you described. As the current through the transformer winding alternates, the two strings of diodes take turns conducting or blocking current.

When the standby switch is closed, then the whole circuit is placed in parallel with those caps and bleeders. SO ther are multiple paths between B+ and ground in that circuitry. ALmost all of that is through the various tubes, plus a little for leakage in the other filter caps. SO in those cases, electrons are flowing up through each of the tubes and back through their loads to the B+ origin at the rectifiers.


In a real sense, the amp runs off the main filter cap, and the rectifier is there to keep it charged.

[Jazz P Bass]

Center Tap Full Wave Rectifier

I think the key word here is center tap.
That is the return, in this case ground.
A full wave bridge rectifier does not have a center tap transformer.
Link:Rectifier - Wikipedia, the free encyclopedia

[trem]

Enzo, Jazz PB,
Thank you so much. I really appreciate the help, you have explained perfectly. Obviously, I only have a rudimentary understanding of electronics, but this puts another feather in my cap so to speak.
The question arose because I completely rebuilt a 1969 Twin for a friend. I decided to just go ahead and install new diodes because I was in there. I installed them per the schematic, but I could not grasp the orientation of those rectifier diodes and it was really bothering me. I was stuck on the side of the road, and you guys helped me out.
Thanks Again

[Jazz P Bass]

Series Rectifier

The series arrangement ups the current capabilities .

[J M Fahey]

*Very* short answer: Capacitors do not conduct DC current; that is, they get charged and that's it.
The rest of the amplifier (power amp, preamp, etc.) gets current from the positive terminal of tha power supply, that current closes the circuit through the grouncd connection, which *returns* to the power supply, specifically the transformer center tap wehich is grounded.
The circuit *always* closes or there would be no "return path" for the electrons.
Hope this is clear enough.

[Gtr_tech]

The series arrangement ups the current capabilities .

You *do* mean voltage, right?

[JHow]

I thought this article gave a good basic explanation:

The Valve Wizard