Bridged Rectifier Question

[hatfield]

OK, I realize this is prolly one of the most remedial of questions, but I'm completely hung up on the wiring of the rectifier diodes in a simple unregulated power supply.

I'm building the Pearl phono boards (which I just finished), and need something to supply the power. I'm following the example that Mr. Colburn was so kind enough to supply, but I've hit a mental roadblock. I have two main questions:

1) The rectifier diodes have four leads: one positive and one negative on either end and two "~." I understand the concept and wiring of the positive and negative terminals, but the "~" has me stumped. How/where would these two leads be incorporated into the circuit?

2) I’ve added two LED diodes (120mA/30mV) with a 2K ohm rectifier - this should be enough to keep the LEDs from frying. Anyway, the ground lead is connected to the cathode, but as indicated on the diagram I've attached... where should my ground lead come from? And for that matter, is there anything missing that I have not indicated as being grounded on the diagram?

Yes, I'm an idiot, but I've over thought this to the point of brain fry. I'm sure it's something so simple that when I see, I'll smack myself in the head for being so thick.

Please lend this class dunce a hand and point me in the right direction.

Thanks everyone,
hat

[Alain Dupont]

hatfield,

I have modified your schema to join the masses...
And for the led use 20 Ma --> 2 K Ohms resistors will do the job.

Good luck.

Alain.

[Bill Fitzpatrick]

In case it isn't clear, the ~ marking indicate where to wire the leads of the transformer secondary. The ~ represents A.C.

[Alain Dupont]

hafield,

I missed one point, the ~ entries of the rectifier bridges
are indicated it this version, they receive the secondary windings of the transfo's.

Hope this helps.

Alain.

[hatfield]

Alain & Bill,

Many thanks for your assistance! Alain, your revised schematic was especially helpful. You two have def. help me to gain a little more clarity; however, in my original drawing, the PS was a dual mono configuration. I had set it up to accommodate two 40V DC feeds - each with its own + & - lead.

I've taken the grounding suggestion, and applied it to my original drawing. Although I'm not sure it is correct in it's execution, I *think* I may be correct in my interpretation. I've circled the revision in red... am I correct in my thoughts?

Thanks again for all the help!!!!
hat (not as lost as before, but not out of the forrest yet...)

[hatfield]

forgot to attach the picture...

[hatfield]

OK, one last thing and I *think* I'll finally have a handle on everything...

With regard to the physical wiring of the bridge using four Schottky rectifiers (as opposed to a single surface mount bridge rectifier), I've attached yet another drawing displaying the four rectifiers used for the bridge on the primary transformer output (the leads are represented by the red and black wires). The blue leads are obviously the DC output, which are marked positive and negative.

I hope this drawing conveys what I am trying to understand (as I'm sure it's somewhat confusing ). Basically, can some kind soul tell me if this is the correct wiring layout for connecting the primary leads of a tororidal transformer to a Schottky rectifier bridge? And are the DC positive and negative outputs wired correctly?

I know, I'm hopeless... but I'm really trying to understand what I'm doing and trying not to blow things up in the process

Thanks again, and again, and again....
hat

[Dr. ODD]

Hi
There is a Mistake in the Schema. The Pearl does not need a +40V - 0 - -40V Psu. It just requires +40 V and ground. The two Bridges in the example in the Pearl Article are for the left and right Channel.

Bernhard

[Dr. ODD]

HI Hatfield

That means yor first Schema was right

Bernhard

[Alain Dupont]

hatfield,

So it's a dual power supply 2 * + 40 Volts

Here is the schema, and the representation of a bridge rectifier
{4 silicon diodes, or 4 Hexfred} in a unique casing.

here is the resulting schema with common masses.

Best regards.

Alain.