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

PC Based Computer music servers, crossovers, and equalization

ES9018K2M, ES9028Q2M, 9038Q2M DSD/I2S DAC HATs for Raspberry Pi
ES9018K2M, ES9028Q2M, 9038Q2M DSD/I2S DAC HATs for Raspberry Pi
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 13th June 2018, 08:15 AM   #421
TioFrancotirador is offline TioFrancotirador  Poland
diyAudio Member
 
Join Date: May 2014
Location: Poland
Quote:
Originally Posted by ofswitched View Post
UltraCapTM LPS-1 is mainly a balance board, you can purchase it yourself.
OK. Got it.
Lets assume would take two caps (5.4V altogether), one balancing board.
Do I charge them altogether with 5.4V through this balancing board? or separately with 2.7V?
What charging current should I use?
How do I know when it is charged? Is there any fix time for charging or CC/CV board stops charging automatically?
  Reply With Quote
Old 13th June 2018, 10:03 AM   #422
Abartels1965 is offline Abartels1965  Netherlands
diyAudio Member
 
Join Date: Jan 2015
Location: Maastricht
Quote:
Originally Posted by nige2000 View Post
is that audio gd's r2r dacs i see in there?
Yes, those are AGD DA-M1 modules in balanced push/pull config, 8 pieces.

Your dining table indeed looks interesting, I like the coffee and muffins
Nice project!
__________________
Pictures of my DA-M1 UltraCap powered Streamer: https://drive.google.com/drive/folde...-V1PFU2DU4brf7
  Reply With Quote
Old 13th June 2018, 10:11 AM   #423
Abartels1965 is offline Abartels1965  Netherlands
diyAudio Member
 
Join Date: Jan 2015
Location: Maastricht
Quote:
Originally Posted by TioFrancotirador View Post
OK. Got it.
Lets assume would take two caps (5.4V altogether), one balancing board.
Do I charge them altogether with 5.4V through this balancing board? or separately with 2.7V?
What charging current should I use?
How do I know when it is charged? Is there any fix time for charging or CC/CV board stops charging automatically?

You charge them in total, 5.4V max, preferably a little lower to extend lifespan.

Charge current depends on the balancing boards and the used ultracaps.
In most cases you can charge them with more amps than your DC-DC CC/CV converter can provide….

CC/CV converters stop charging when reached the preset voltage.

I use these:

Max 5A Adjustable CC CV Step Down Receiver Charge Module Digital Voltmeter Ammeter Display LED Driver for Arduino Non isolated in Max 5A Adjustable CC CV Step Down Receiver Charge Module Digital Voltmeter Ammeter Display LED Driver for Arduino Non-isolated van Geintegreerde Schakelingen op AliExpress.com | Alibaba Groep

These can charge with 5A max, but, setting voltage below 2V is not stable.
__________________
Pictures of my DA-M1 UltraCap powered Streamer: https://drive.google.com/drive/folde...-V1PFU2DU4brf7
  Reply With Quote
Old 13th June 2018, 11:45 AM   #424
schultzsch is offline schultzsch  Europe
diyAudio Member
 
Join Date: Mar 2009
It would be nice to have a charger that changes from cc to cv when the first balancing circuit activates. This can be done via some optocouplers. One optocoupler connected in parallel with each of the balacing resistors of each cap.
I have done something similar with lipos that are known to get slowly damaged in the cv part of the charge. So even if I charge a little bit less of the max capacity I get a longer life for the cells.
  Reply With Quote
Old 13th June 2018, 12:13 PM   #425
Abartels1965 is offline Abartels1965  Netherlands
diyAudio Member
 
Join Date: Jan 2015
Location: Maastricht
Quote:
Originally Posted by schultzsch View Post
It would be nice to have a charger that changes from cc to cv when the first balancing circuit activates. This can be done via some optocouplers. One optocoupler connected in parallel with each of the balacing resistors of each cap.
I have done something similar with lipos that are known to get slowly damaged in the cv part of the charge. So even if I charge a little bit less of the max capacity I get a longer life for the cells.
Ultracaps can be charged with their continuous decharge amperage.
My Bussmann Cooper ones, 100F, can be charged continuously with 11 Amps,
and peak charged 61 Amps. No need to throttle here...


The CC/CV converter noted earlier does charge CC to CV.
__________________
Pictures of my DA-M1 UltraCap powered Streamer: https://drive.google.com/drive/folde...-V1PFU2DU4brf7
  Reply With Quote
Old 13th June 2018, 01:48 PM   #426
schultzsch is offline schultzsch  Europe
diyAudio Member
 
Join Date: Mar 2009
Quote:
Originally Posted by Abartels1965 View Post
Ultracaps can be charged with their continuous decharge amperage.
My Bussmann Cooper ones, 100F, can be charged continuously with 11 Amps,
and peak charged 61 Amps. No need to throttle here...


The CC/CV converter noted earlier does charge CC to CV.
Yes you are right but if you have an imbalance between the voltage on the caps the balancing circuit wonít manage to discharge 11 amps to keep steady the voltage of the cap and you will overcharge it.
With very good caps/cells this is very less to happen but count in that with aging the impedance increases unequal for each cap/cell and sooner or latter the condition I mention above could happen. Another thing to mention is that even the best cells/caps on the market donít have perfect matching impedances.
So when used at high currents(charge or discharge) itís always best to have a bms that manages the overcharge/overdischarge conditions.
  Reply With Quote
Old 13th June 2018, 01:49 PM   #427
iancanada is offline iancanada  Canada
diyAudio Member
 
iancanada's Avatar
 
Join Date: Dec 2009
Location: Toronto
ES9018K2M, ES9028Q2M, 9038Q2M DSD/I2S DAC HATs for Raspberry Pi
Quote:
Originally Posted by Abartels1965 View Post
Ian,

My ultracaps project you saw (powering ALL dac-voltage rails separately, and ALL other voltage rails for fifo II/Isolator/dualXO II/ etc. as well) is also based on COOPER BUSSMANN HV1635 but the 100F version. They are not the best ultracaps, the Maxwells are much better, so can you imagine how yours perform

Btw, please do NOT go the LPS-1 route, since they still use regulation which ruins the perfect ultracaps specs!!!!!

My wish for you to design :

Design a circuitry, microprocessor driven, with the possibility to set a LOW threshold Voltage to switch between two banks of ultracapacitors. Switching devices based on VERY LOW RDS-ON MOSFETS, capable of switching several Amperes for fast charging.

It also would be nice if design also could handle voltages up to 60V for powering power amps, AND ESPECIALLY for DRIVER AMP circuitry!!!
This way we also could use this design to power the DRIVER AMP section in our power amps, which will make a HUGE difference in SQ!!!

And last, but definitely not least, this could be the holy grail to power output stages.....


About your concern overpowering the ultracaps while switching, when microprocessor controlled, you could build-in a very short delay time, which will be compensated by a good buffer elco at it's output, that is what I use to prevent hick-ups in power delivery while switching the banks.


I am VERY sure you would have a HUGE hit on the DIY audio market, and MANY people would be interested in buying such a design, including myself!!


Before I forget, since Class-D designs are "the new thing", it is very good possible that in the near future there will be new Class-D designs which CAN surpass Class-A Mosfet amplifiers SQ. ALL Class-D amplifiers do prosper from GOOD power source. So, can you imagine how a GOOD Class-D amp would sound if powered by Ultracaps?


About Mosfets for switching, ST for example has a 60V 120A 0.0024 RDS-ON mosfet which would be a very good choice!

http://www.st.com/content/ccc/resour...CD00272622.pdf

Don't forget using them for positive AND ground circuitry!


Btw, Powerex Incorporated has switching mosfet modules with 177 micro ohm rds-on,,,,, so maybe there are other contenders on the market tooÖ.


Keep up the good work Ian

Best regards,
Alex
Hi Alex

For the low RDS-ON MOSFET, the biggest problem would be the isolation. It's almost impassible to get isolated from charger when switches to circuit because of the body diode.

In this case, traditional relay still seems a better option for switching ultracapacitor banks. But It would be challenge to find relays with really low audible noise.

Ian
  Reply With Quote
Old 13th June 2018, 05:48 PM   #428
schultzsch is offline schultzsch  Europe
diyAudio Member
 
Join Date: Mar 2009
Ian,

If using relays to connect the charger to the caps I think that a pre charge circuit will be needed. Counting in that the caps have very low impedances and high charging currents are needed, sooner or later the relay contacts will weld together. It may seem a joke the welding stuff but my daily job implies lithium batteries and inverters so I assure you I have seen enough high current contactors with the contacts welded because of the high inrush currents that the capacitors from the inverters present to the contactor when are completely discharged. I solved this problem adding a second contactor with a power resistor in series with the contacts. This network stays on for few seconds after which is shunted by the contactor without the resistor and after I disable the contactor with the resistor.
It comes a bit complicated if you want something reliable in time.
  Reply With Quote
Old 13th June 2018, 07:35 PM   #429
iancanada is offline iancanada  Canada
diyAudio Member
 
iancanada's Avatar
 
Join Date: Dec 2009
Location: Toronto
ES9018K2M, ES9028Q2M, 9038Q2M DSD/I2S DAC HATs for Raspberry Pi
Quote:
Originally Posted by schultzsch View Post
Ian,

If using relays to connect the charger to the caps I think that a pre charge circuit will be needed. Counting in that the caps have very low impedances and high charging currents are needed, sooner or later the relay contacts will weld together. It may seem a joke the welding stuff but my daily job implies lithium batteries and inverters so I assure you I have seen enough high current contactors with the contacts welded because of the high inrush currents that the capacitors from the inverters present to the contactor when are completely discharged. I solved this problem adding a second contactor with a power resistor in series with the contacts. This network stays on for few seconds after which is shunted by the contactor without the resistor and after I disable the contactor with the resistor.
It comes a bit complicated if you want something reliable in time.
Hi schultzsch,

Thank you for sharing your experience. To use relays for ultracapacitor power supply, the current has to be reduced below rated level of relay at the moment of switching.

You are right, additional relay might be needed for pre-charge or pre-discharge. And also we don't really need that high charging current though it is capable for. There will be a lot of considerations to take.

Regards,
Ian
  Reply With Quote
Old 14th June 2018, 11:33 AM   #430
TioFrancotirador is offline TioFrancotirador  Poland
diyAudio Member
 
Join Date: May 2014
Location: Poland
@iancanada
Ian,

How about the following scenario:
What is your typical listening session time? Hours?
What is the acceptable time for your DAC to power up? Minutes?
What if you have Super Capacitor PSU for your DAC that would charge quickly (minutes) but only from time to time and then discharge for hours …

Would two BIG 3000F Maxwell cells meet those requirements? Those two could be charged with dozen of Amperes in minutes and discharge with hundreds of miliAmpers in hours with assumption to allow some small voltage drop ~0.5V. In such case discharge to charge ratio is around ~1:60 (one minute charging to one hour of discharging in this case). I assume voltage drop here from 5.4V to 4.9V, but could be lower down to acceptable local LDOs input levels.

No switching here. The use case here is like with Power Bank, but with quick automatic charging only from time to time. Most of the time (98% ?) the DAC would be powered with SuperCaps. Short charging periods could be indicated with some LED, so you would know when to plug the ears

For me something like this seems to be far easier to build, if one accepts those short charging periods.

What do you think guys?
  Reply With Quote

Reply


ES9018K2M, ES9028Q2M, 9038Q2M DSD/I2S DAC HATs for Raspberry PiHide 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
I/V stage for ES9028Q2M gandolf Digital Line Level 25 9th February 2018 06:04 AM
ES9028Q2M balanced output evert1 Digital Line Level 0 26th December 2017 01:30 PM
ES9018K2M: best (Raspberry)-OS/384 khz + dtoverlay sfb2 PC Based 2 30th May 2017 09:43 PM
Hats off to Mr Pass, encouragement to new members Russellc Pass Labs 10 17th May 2015 08:23 AM
Hats make better bass? xstephanx Subwoofers 11 9th February 2005 10:59 AM


New To Site? Need Help?

All times are GMT. The time now is 02:26 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki