• Disclaimer: This Vendor's Forum is a paid-for commercial area. Unlike the rest of diyAudio, the Vendor has complete control of what may or may not be posted in this forum. If you wish to discuss technical matters outside the bounds of what is permitted by the Vendor, please use the non-commercial areas of diyAudio to do so.

Placid-BP Bipolar Shunt Regulated Power Supply

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Also, what does CFP stand for? Constant something I'm sure.

Thanks again,
Tom

I Think you have the general idea.

CFP stands for complementary feedback pair.

The shunt reg has two main components(per side). The Constant current source, and the shunt. The shunt in this case is a CFP which is driven by an opamp. The whole thing is in a feedback loop and adjustable for both current and output voltage.

A CFP is basically a way to create a high current gain similar to a Darlington Pair.

2-3W per power device could easily be handled with 2" HS.

You could even do more than that if you use a larger heat sink. Once you reach a certain point a series reg would be a more sensible choice.

Cheers!
Russ
 
How do you think this would work with IVY or Ballsie? If I understand correctly how you've configured it, Placid should be a good upgrade to your LCBPS for most applications...?

I'm planning to order an Opus ASAP, along with an IVY as a balanced buffer and SE converter. A Placid would be a great touch. (even if I need to wait a bit for it)

Thanks!

Sure it would be a great choice for most of our designs. Including Ballsie Lite, Ventus, Ivy, Ivy II, Mesh, Buffalo32S.

It should provide better load regulation and line regulation than a LCBPS. It also has a very low noise voltage reference (2 green LEDSs with 1K/100uf filter) and as long as a low noise high PSRR opamp is used you will achieve excellent results.

Cheers!
Russ
 
Placid BP details

Hey folks here is the schematic and 100% scale PDF for those planning case space etc.

The cct is not very complicated, but very effective. :)

Cheers!
Russ
 

Attachments

  • placid_bp_2_1_1.pdf
    36.9 KB · Views: 395
  • placid_bp_2_1_1_board.pdf
    96.3 KB · Views: 244
  • placid_bp_2_1_1_pcb.jpg
    placid_bp_2_1_1_pcb.jpg
    206.6 KB · Views: 1,183
Hi Russ

Have you thought about separating the grounds of the two circuits? You would need a 4-pin phoenix connector (instead of a 3-pin) at the output. Having the circuits separated from each other would make the supply more universal, as it could also be used as dual supplies. Even if used as a bipolar supply, it may be preferable to join the grounds at the load, not at the source. May help in avoiding ground loops.

Kurt
 
It's Bipolar, meaning they are supposed to share GND. It designed to work as such, both voltage references have to share the same 0V point. :)

Its a single supply with three voltages V+/0V/V- not two supplies. :)

Now having said all that, if you like you can use two (non-bipolar) placid in series and achieve what you want.

Cheers!
Russ
 
Last edited:
Here is a picture of an assembled Placid BP with kit components:

An externally hosted image should be here but it was not working when we last tested it.


The BP kits are almost ready, and should be available this week. I am starting up the Positive-only kits this week as well, so hopefully they will be ready by the end of the week, or early next week.

Pricing will be as follows:

Placid (single positive-only) complete kit: $40
Placid BP (bipolar) complete kit (including mounting hardware): $60
 
....The BP kits are almost ready, and should be available this week....

Russ and Brian, this all looks splendid ;-)

Russ
p.s. Is it me or is the QP2 in the wrong way round? Hard to see from the picture but looking at the board layout posted earlier, it appears to be the opposite way to the the others, but not in the picture. Could just be the picture of course... or my eyes...
 
diyAudio Chief Moderator
Joined 2002
Paid Member
Is it possible to have the dimensions of the heatsinks? I'd like to look for 1-inch replacements. :)

Can't they be soldered underneath the board, the FJPs I mean, and mounted with their backs against the metal floor of the box, or on a thick aluminum plate? That would avoid sinks up to a generous enough current and keep it almost flat for height?
 
Yes, I thought of mounting them on the enclosure's floor but they might end up being used on something different than a Buffalo where better heat management will be required.
Since I have an order pending at Farnell I though I might think ahead and order these now so that I have the luxury of choice! :)

They are a standard part, so changing to 1" or 2" is easily accomplished.

Sorry that I insist Brian but "standard" is a very broad notion.. :D
Could I have exact width and depth or, if it's easier for you, manufacturer and part number so I can look it up?
 
Last edited:
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.