Portable battery powered Class D - diyAudio
Go Back   Home > Forums > Amplifiers > Class D

Class D Switching Power Amplifiers and Power D/A conversion

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 6th October 2004, 08:50 PM   #1
edpgc is offline edpgc  United Kingdom
diyAudio Member
 
Join Date: Apr 2004
Location: Birmingham, UK
Default Portable battery powered Class D

Right I'm trying to get as much power out of as few volts as efficently as possible. It seems to get around 4 Watts i need 7 volts. However I was thinking since these class D's are essentially switch mode pwer supplies, why can't they bet set-up to switch a higher voltage than the input voltage? Therefore letting me get 10 Watts or more from 5 volts!?

Has anyone achieved this? Perhaps I should just put a switch mode supply before the class D though I'm sure this is asking for trouble! Any ideas or suggestions for ultra efficient low voltage class D chips!?

Cheers
Ed
  Reply With Quote
Old 7th October 2004, 08:24 AM   #2
Account Disabled
 
Join Date: Feb 2004
Send a message via AIM to classd4sure Send a message via MSN to classd4sure
Hi,

You mean an audio class d amp working as a buck/boost? Don't think so. Wwhy not add an extra cell to your battery pack?
  Reply With Quote
Old 7th October 2004, 09:19 AM   #3
diyAudio Member
 
Join Date: Dec 2002
Location: Slovenia
Hi,

take a look at http://www.jam-tech.com/. You might also search their patents. I do not know if their products work, because you can patent anything .

Best regards,

Jaka Racman
  Reply With Quote
Old 2nd December 2008, 01:24 PM   #4
Davey T is offline Davey T  United Kingdom
diyAudio Member
 
Join Date: Jul 2007
I was about to post a similar thread but found this one and thought i would expand on it.

----------------------------

The best portable battery loudspeaker/amplifier solutions use a single lipo 3.7v battery which can be charged off usb and doesn't require cell balancing etc. You quiescent power consumption is nice and low too as you are operating from a low voltage = lower switching losses.

However, this limits you to about 2 watts of power.

Most everyday use of the speaker means thats its running within this 2w power usage band. However, some days you would like the ability to really crank it and have 10-20w at your disposal. This would be very useful and a big selling point. BUT How could this be acheived?

a) step-up before the class-d?
b) more battery cells and live with the increased quiescent power consumption?
c) boost-buck?
d) cuk converter?
__________________
www.minirigs.com
  Reply With Quote
Old 6th December 2008, 09:04 PM   #5
diyAudio Member
 
Join Date: Dec 2003
Location: Munich
Steping up with a simple boost converter should do the job.
  Reply With Quote
Old 8th December 2008, 01:31 AM   #6
diyAudio Member
 
Join Date: May 2008
Send a message via MSN to ArjenShenzhen
Default steppin it up

Hey there,

You can indeed use a step up converter, but you need to understand that you either use a high voltage, or a high current. if you use 1 A at 12 volts, you have 12 watts, if you want 12 watts at 3.7 volts you need about 3 A, so your battery would be empty much sooner. its a much better idea to use 3X 3.7 volts cells that you can switch parralel for charging, and serial for discharging. and it still keeps it relatively simple.
Then you can use a wide range of medium power IC's.

Class D is best for battery powered systems as they have the highest efficiency.

there are many people selling these boards, and i also have them.

if you need over 20 watts, battery power will claim a more heavy burden on your back as the battery packs are getting heavy, making a more efficient speaker system is also worth allot.
__________________
Always check the power supply... and my spelling...
  Reply With Quote
Old 9th December 2008, 01:03 PM   #7
Davey T is offline Davey T  United Kingdom
diyAudio Member
 
Join Date: Jul 2007
I think i'l stick to the 3-cell in series. I've come up with a neat and simple charging/balancing circuit.

I did think about switching between series/parallel but its a bit tricky to wire up and what if the cells aren't exactly balanced before you put them in parallel?
__________________
www.minirigs.com
  Reply With Quote

Reply


Hide 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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Powerful small/thing portable speakers? (battery powered?) Anirak Everything Else 2 24th March 2009 09:29 PM
portable batterie powered amp (2x 2W) ??? Artemus GF Class D 6 9th July 2008 10:41 AM
Portable T-Amp Powered Boom Box ramdog12345 Class D 2 22nd April 2007 08:40 AM
Battery powered portable Class-D mono amp >50W RMS tonfelix Class D 1 29th April 2006 02:08 PM
Making USB powered gear, portable?? redrabbit Power Supplies 3 3rd April 2005 12:32 PM


New To Site? Need Help?

All times are GMT. The time now is 09:12 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2