Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Group Buys Members group buys

GB for Simple Cap-Mx Regulated Low-Noise PSU
GB for Simple Cap-Mx Regulated Low-Noise PSU
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 24th February 2019, 11:38 AM   #11
Mindfunk is offline Mindfunk
diyAudio Member
 
Join Date: Dec 2015
DrPro - 2 boards - USA
Vunce - 2 boards - USA
goldkenn - 4 boards - Hong Kong
Yatsushiro - 2 boards - France
Mindfunk - 4 boards - Germany
  Reply With Quote
Old 24th February 2019, 02:54 PM   #12
xrk971 is offline xrk971  United States
Got Foam?
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC area
GB for Simple Cap-Mx Regulated Low-Noise PSU
Thanks for the continued interest folks. It has just come to my attention that a 3A 5v 4.4uV LDO VR just came out from TI:

http://www.ti.com/product/TPS7A84A

Interesting for RPi
__________________
XRKaudio https://www.etsy.com/shop/XRKAudio
  Reply With Quote
Old 24th February 2019, 03:26 PM   #13
drpro is offline drpro  United States
diyAudio Member
 
Join Date: Jan 2014
Location: Nashvegas
GB for Simple Cap-Mx Regulated Low-Noise PSU
X that would be really nice. I am interested in RPI power. Having 3amps would be great.
__________________
I must build. Pass F4s, F6, M2, BA-3 preamp, MoFo, ImPasse preamp, Whammy headamp, Aksa's Lender preamp, Salas DCG3 headphone/preamp, XRK971 PCA & DCA headamp Bruno Putzey's balanced preamp, Doug Self preamp, Pete Millet Korg headamp.
  Reply With Quote
Old 24th February 2019, 04:49 PM   #14
xrk971 is offline xrk971  United States
Got Foam?
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC area
GB for Simple Cap-Mx Regulated Low-Noise PSU
The 3A 5v regulator is a separate project - but let me see how we can make one. 3A at 5v is 15w upstream.
__________________
XRKaudio https://www.etsy.com/shop/XRKAudio
  Reply With Quote
Old 25th February 2019, 04:59 AM   #15
Roundtoit is offline Roundtoit  United States
diyAudio Member
 
Join Date: Feb 2016
Location: By a creek in Missouri
DrPro - 2 boards - USA
Vunce - 2 boards - USA
goldkenn - 4 boards - Hong Kong
Yatsushiro - 2 boards - France
Mindfunk - 4 boards - Germany
Roundtoit - 2 boards - USA
  Reply With Quote
Old 25th February 2019, 06:32 PM   #16
xrk971 is offline xrk971  United States
Got Foam?
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC area
GB for Simple Cap-Mx Regulated Low-Noise PSU
Thanks to member Twocents for being a beta tester on v1 - nice build with an eBay TPS7A4xx LDO regulator.

Best 5V SMPS ?-xrk-psu-low-current-ultralow-noise-5v-jpg
__________________
XRKaudio https://www.etsy.com/shop/XRKAudio
  Reply With Quote
Old 27th February 2019, 08:42 PM   #17
maartn is offline maartn  Netherlands
diyAudio Member
 
Join Date: Jun 2017
DrPro - 2 boards - USA
Vunce - 2 boards - USA
goldkenn - 4 boards - Hong Kong
Yatsushiro - 2 boards - France
Mindfunk - 4 boards - Germany
maartn - 3 boards - Netherlands
  Reply With Quote
Old 27th February 2019, 11:32 PM   #18
Lo_Tse is offline Lo_Tse  Canada
diyAudio Member
 
Join Date: Dec 2006
Quote:
Originally Posted by xrk971 View Post
Have you ever found yourself making a basic circuit that is so simple, that you say to yourself, "it's so simple I will just make it from scratch on veroboard..." It works so well and is so useful, it becomes an integral part of many of your future projects. Before you know it, you have hand-assembled on veroboard the same circuit a dozen times. Well that's what I have been doing whenever I needed a source of ultra quiet (battery-like) single-rail DC power in the range of 5v to about 32v and current under 1amp. I use this countless times for low noise headphone projects, DACs, etc. Well, I sort of got tired of making them from scratch and worked with JPS64 to put it on a simple 50mm x 75mm board the following: a CLC filter, an Easy-Peasy Juma cap multiplier, and a 78xx regulator, and throw in some smoothing caps, snubbers, output bypass caps, and LED power indicator, and input/output terminal blocks. I typically use a 12v 1000mA Class 2 transformer wall-wart ubiquitous with routers and switches that we accumulate over the years. That then powers a clean DC-DC step up converter to about 4v+ regulator dropout (circa 2v) above our needed voltage. So for example, if you need a clean 18v supply, add 5v or 23v as the DC-DC stepup output. Put that into this unit, and let its cap CLC filter, cap multiplier, and voltage regulator give you a clean source of 18v with ripple as low as 4uVrms (if you use a TO-220 formatted TPS7A4xxx LDO regulator). If you can live with 50uV noise,a simple 7818 regulator will work fine. I have used this on countless headphone amps and the noise floor measures flat like a battery. Absolutely no mains hum gets through.

Thanks to JPS64 for a great layout with all the customary via stitching and double planes of copper for low impedance current paths.

So here is the circuit:
Click the image to open in full size.

This is what it looks like built up in prototype stage v1:
Click the image to open in full size.

And here is the board will look like for the v2 (will be 1.6mm thick, 1oz copper, green mask, and ENIG finish):
Click the image to open in full size.

Here is the top view of the parts placement. BOM for the board is relatively cheap if you are going with just a 78xx. You need an N-channel TO-220 MOSFET such as an IRF610 or the Fairchild equivalent. IRF510 etc works well too. A few caps and resistors, some connectors, and a basic inductor to keep the DC-DC noise even more isolated.
Click the image to open in full size.

If interested in this little PSU board as a GB, please add your name, number of boards, and country to ship to below.

Like this:
DIYJohnDoe - 2 boards - USA

Pricing will be about $10 ea and tracked shipping in a padded bubble envelope mailer is the usual $5 in US, $10 for CAN, and $15 everywhere else. Maximum 8 boards per order for the above shipping prices.

Thanks,
X

Some supporting info, you can see in the photo below, a hand-made variant of this PSU (without a voltage regulator) powering my Aksa Lender preamp, the DC-DC step up is visible as well. Here I was running 48vdc output so a 78xx regulator could not have been used as they max out at 35vdc input:
Click the image to open in full size.

Here is the FFT from the Aksa Lender showing the typical clean battery like noise floor:
Click the image to open in full size.

Another example is the PSU that is built into the DCA Single ended Class A HPA (also without a VR):
Click the image to open in full size.

Here is the typical FFT from the DCA:
Click the image to open in full size.

Finally, another example is the similar PSU built into the Aksa-Lender preamp GB:
Click the image to open in full size.

And typical FFT of the Aksa Lender putting out 20vpp into 7kohms:
Click the image to open in full size.

So you can see how well this supply works in general and how I keep coming back to it. Just use a $4 to $7 DC-DC step up to get whatever voltage you need.

These types of DC-DC work well, for example:

DC DC 250w Boost Converter Step-up 10a Constant Current Power Supply LED Driver | eBay

400W 15A DC Step-up Constant Current Power Supply LED Driver Boost Converter | eBay

400W 15A DC Step-up Constant Current Power Supply LED Driver Boost Converter | eBay

DC-DC Step-up Boost Converter Constant Current Power Supply 10A 250W LED Driver 6472005271954 | eBay

Edit Feb 25, 2019: Member Twocents was a beta tester for v1 and he installed an eBay 5v TPS7A4xx LDO board on it - nice work!
Click the image to open in full size.

And use a 12v 1000mA Class 2 Wall wart like this, for example:
Click the image to open in full size.
Class 2 Power Supply Unit FL41A20U120V120A1000 Adapter 12V 1000mA Charger | eBay
Hi there

Would you mind telling me what is the value of the inductor in the CLC section? I am checking to see what components I already have and what I need to purchase for this PSU before deciding whether to join this GB. Thanks!

Regards,
  Reply With Quote
Old 28th February 2019, 12:09 AM   #19
xrk971 is offline xrk971  United States
Got Foam?
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC area
GB for Simple Cap-Mx Regulated Low-Noise PSU
It’s very flexible what size inductor you can use. The characteristic cutoff frequency of an LC filter is 1/(2 pi sqrt(LC)). If you use a 1000uF cap and say 10uH inductor, you have 1.6kHz filter cutoff - well below the switch frequency of the SMPS by many octaves so the filtering should be steep. You could even use a much smaller cap like 100uF and it would be fine as that is 16kHz and switchers are 200kHz to 400kHz.

Make sure you have a resistor in parallel with the inductor to prevent oscillation. Something like 33R to 47R or 51R works.

The inductor specified in the schematic is a Wurth 7447017 22uH. Or 1072Hz cutoff frequency.

7447017 Wurth Electronics Inc. | Inductors, Coils, Chokes | DigiKey
__________________
XRKaudio https://www.etsy.com/shop/XRKAudio

Last edited by xrk971; 28th February 2019 at 12:14 AM.
  Reply With Quote
Old 28th February 2019, 12:37 AM   #20
Lo_Tse is offline Lo_Tse  Canada
diyAudio Member
 
Join Date: Dec 2006
Thank you for the fast response!!
  Reply With Quote

Reply


GB for Simple Cap-Mx Regulated Low-Noise PSUHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
simple low noise regulated supply sumotan Power Supplies 20 26th November 2015 03:00 PM
Low noise Regulated +-12v supply? Supergregg Power Supplies 4 6th May 2009 03:44 PM
Idea(s) for simple HV regulated psu rotation Tubes / Valves 6 21st February 2009 08:14 PM
Regulated DC PSU - Plain and simple please? GlidingDutchman Solid State 156 26th June 2008 12:20 PM
57 V regulated low noise Luis P. Solid State 8 7th February 2006 05:07 PM


New To Site? Need Help?

All times are GMT. The time now is 11:07 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki