[kevin gilmore]

OK, so i'm a little busy...

Here is the power supply board REV ZERO. I have not checked this
yet, someone else should. I don't even have all the parts to make
sure they fit in the boards. The board is tight to keep it inside the
20 square inches...

http://gilmore.chem.northwestern.edu/dynahips.zip

you will need a gerber viewer to look at this.
I would not have boards made on this just yet...

not the turkey present i was planning on...

 

[randytsuch]

Is there a schematic to look at?

Randy

 

[kevin gilmore]

Same thing as the dynalo schematic with lm338's replacing the
pre-regulators, and opa541's replacing the opa548's. And a few
resistor changes...

 

[bg4533]

Do you have a rough estimate as to how much this PSU will cost?

 

[kevin gilmore]

6 caps at about $8 each
2 caddock power resistors at $5 each
2 opa548's at $17 each
2 lm338 at $2 each
board at $10 in quantity
ref02 at $9
8 fast recovery diodes at $1

few other parts...

NOTE: there are definitely some problems with this layout.
The opamps and the power resistors are too close. So don't
go making boards just yet.

Note2: Board now at rev 1. Everything fits. Very tight however.
Just barely under 20sq. Same file same name.

 

[dgardner]

For those without a gerber file viewer...
Here is the topside, bottomside, and silkscreen so far

View a jpeg of artwork = 471KB

 

[Talonz]

This is great

We only need one power supply then, correct?

 

[strohmie]

One power supply board and likely a heat sink as well, along with the other parts. Hopefully Kevin organized the board such that the regulators can be cooled using the same heat sink, a la Dynahi's output transistors.

 

[sft]

You need a large heatsink .

 

[kevin gilmore]

Yep, same heatsink. That is the idea.
Yes it gets hot.

 

[dgardner]

So... the question remains... does this puppy put out 4A per rail? or 2A per rail? It looks like if the transformer is beefy enough and the heatsinks are big enough, one unit could power the dynamite configuration. Am I right?

 

[kevin gilmore]

with the .2 ohm current limit resistors, the maximum current is about
3 amps. Certainly enough to run a dynomite, but not enough to run
speakers. But if you are going to run a dynomite, you really want
2 power supplys for dual mono...

 

[eweitzman]

Where'd the trick 5uF caps go -- no more overkill?

- Eric

 

[sft]

4700uF + 470uF + 1uF(PP, if you want) is absolutey enough for small power amp.

 

[kevin gilmore]

quote
Where'd the trick 5uF caps go -- no more overkill?
- Eric

You are kidding right?? If i make room for the caps the board
gets a whole lot bigger. So for the people who want them
(which includes me) they go in between the power board and
the amp boards.