12vdc from 120ac? - Page 2 - diyAudio
Go Back   Home > Forums > Design & Build > Construction Tips

Construction Tips Construction techniques and tips

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 9th November 2013, 12:12 PM   #11
JMFahey is offline JMFahey  Argentina
diyAudio Member
 
JMFahey's Avatar
 
Join Date: Mar 2009
Location: Buenos Aires - Argentina
Yes.
1) you could probably work with no more than 25/30mA.
Even if many Leds are lit, they can be wired in series, so current consumption does not add up.

2) in such tight spaces, SMPS is your friend, but even so, you may salvage some proper sized conventional transformer, from stuff such as, say, an old clock radio.
Or pull the SMPS from a dead DVD player or something.

3) you could make a passive VuMeter, where rectified audio voltage which already feeds the speaker, can be rectified and used to directly light Leds.
No need for a PSU.
  Reply With Quote
Old 9th November 2013, 01:11 PM   #12
diyAudio Member
 
KatieandDad's Avatar
 
Join Date: Nov 2011
Location: UK
Andersonix just beat me to it. Yes, a walmart plugtop may well have the tiny board that you are looking for.
  Reply With Quote
Old 10th November 2013, 03:39 AM   #13
diyAudio Member
 
lanchile's Avatar
 
Join Date: Sep 2008
Location: AREA 51
it sounds good idea to strip off a casing...I have to find a very small one. Thanks for suggestions guys!
__________________
Make it simple...Make it better!
  Reply With Quote
Old 10th November 2013, 03:47 AM   #14
diyAudio Member
 
lanchile's Avatar
 
Join Date: Sep 2008
Location: AREA 51
Quote:
Originally Posted by sofaspud View Post
You should have a better idea of the supply requirements to obtain a helpful response. A LM3915 and 10 LEDs shouldn't require half an amp. Less than 250mA seems more sensible; if all the LEDs stay lit at once you should redesign the meter!
Having said that, there may be a ready-made encapsulated module that you could use. Something like this VSK series from CUI found in Digikey's catalog
Very nice sofaspud . I am going to put it on my list of candidate for sure! Thanks!
__________________
Make it simple...Make it better!
  Reply With Quote
Old 10th November 2013, 04:55 AM   #15
diyAudio Member
 
Join Date: Apr 2003
Location: Portland,Oregon
Blog Entries: 4
Send a message via AIM to DigitalJunkie
I tore down one of the white plug-in iPod/iPhone cube style chargers a while back,cause I was curious. They really pack it in that little cube! The only downside is that it's 5V output,not 12V.
Something similar could probably be found with some searching around the local thrift-store,or such.
  Reply With Quote
Old 15th November 2013, 06:07 PM   #16
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
A regulated 12Vdc at a continuous 1A requires a 12Vac 2Aac transformer.
Unregulated needs 9Vac 2Aac for continuous duty. For cool running double the AC current ratings.

For an intermittent 1Apk and around 150mAdc continuous, then the current rating could be reduced to around 500mAac.
__________________
regards Andrew T.
  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
12vdc to 150vac adusson Tubes / Valves 19 9th August 2013 12:40 AM
85vDC - 12vDC rookie amp builder Solid State 5 3rd March 2011 02:41 AM
Use of transistor for switching 120AC xxguitarist Everything Else 6 27th March 2009 08:02 AM
12vDC to 12vAC Cxrazy Parts 10 21st January 2008 02:11 PM
12vac to 12vdc what all do i need Big_Tires Solid State 5 2nd September 2004 12:33 AM


New To Site? Need Help?

All times are GMT. The time now is 08:36 PM.


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