• These commercial threads are for private transactions. diyAudio.com provides these forums for the convenience of our members, but makes no warranty nor assumes any responsibility. We do not vet any members, use of this facility is at your own risk. Customers can post any issues in those threads as long as it is done in a civil manner. All diyAudio rules about conduct apply and will be enforced.

Scalable PSU/regulator GB

Status
Not open for further replies.
Jump to Latest
#161
Jens,
I leave the layout to you.
Your board design skills are way beyond anything I could ever aspire to.

Yes, I would want to see the PCB in my hands before suggesting the detail of the mod I have in mind. I have a few redundant centre tapped and dual secondary transformers I want to use.
I also want to totem pole extra voltage on to the main PSU Vrails to give a regulated supply for the volt amp stages of your Leach layout and some others I have. The separate rectifiers suit this as well.

"Scalable" really means total flexibility in this thread.
 
#165
Here are some more numbers (just measured)

The 10mVpp was measured with a lot less input capacitor.

C filter : 2 x 1000µF
C out : 22µF
Iout : 750mA => Pout 11.25W

Vripple on filter = 2.7Vpp
Vripple out = 2.8 mVpp

PSRR = -20 x log(2.8mV/2.7V) = 59dB

At 0A out the ripple noise drowns in the background noise on my scope @ 2mV/DIV

\Jens
 
#166
peranders said:

Isn't this rather much when others state levels in the uV range?

A simple LM317 will have up to 90 dB ripple rejection, a factor 100 better and output impedance of a couple of milliohms, a factor 100 better also.
Click to expand...


Really? at what load/Iout?

AFAICT the fairchild is measured at 0.5A @10V out - correct? and is typ = 60 dB

The National type is specified af Iout=10mA

At 10 mA out I'm unable to measure the ripple with the scope I have at home.

\Jens
 
#167
a comment on power supply ripple for novices

Power supply ripple 49 db below the signal level doesn't sound great at first glance.

But it is NOT what will appear on the signal. The power supply ripple appearing in the signal will be reduced by the op amp's PSRR. If you are using the OPA2134, that's 106 db. So, there will be a bit of ripple 155 db below the nominal signal level and will be further reduced in typical applications drawing less current from the supply.
 
#169
Re: a comment on power supply ripple for novices

BobEllis said:
Power supply ripple 49 db below the signal level doesn't sound great at first glance.

But it is NOT what will appear on the signal. The power supply ripple appearing in the signal will be reduced by the op amp's PSRR.
Click to expand...
... yes, but what were the design goals? Good to remember. Does this filter board need better supply quality than from a plain LM317?
 
#175
With the independent bridges you'll create a short circuit if you tie them together with a center tapped winding. The positive and negative portions are designed to be completely independent.

Use of a center tapped transformer will be addressed shortly.
 
#176
Center tapped Transformer use

If you want to use a center tapped transformer (15-0-15) with this board, do the following:

OMIT D2, D4, D12, D14, C1, C8, C19, C26.

Tie the positive and negative section grounds together

Connect center tap to the combined ground

Tie together AC1-1 and AC2-1

Tie together AC1-2 and AC2-2

AC inputs to the combined AC terminals
 
#177
The buy closes today.

There are 61 paid orders out of 75 confirmed, and another 7 who signed up but didn't contact me.

I'll be packing and shipping over 21,000 boards and parts. :bigeyes: What was I thinking? 🙄 At least I have a teenager who needs prom tickets to help me.

The boards will be delivered in about a month. I'll be packing PSU kits in the meantime. But, it will take a little longer to get this buy shipped out than the last one.
 
Status
Not open for further replies.
Top Bottom