chipamp PSU LED value - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

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 20th August 2013, 05:28 PM   #1
davym is offline davym  Scotland
diyAudio Member
 
Join Date: Jul 2013
Location: Under a cloud
Default chipamp PSU LED value

I'm about to put together a chipamp (Brian GT) LM3886 kit and was wondering if I could connect the LED in my mains power on/off switch to the LED connection point on the PSU board in place of the one which came with the kit.

I don't see why not but thought i'd ask before I went ahead.

Cheers

Davy
  Reply With Quote
Old 20th August 2013, 08:26 PM   #2
Minion is offline Minion  Canada
diyAudio Member
 
Join Date: May 2006
Location: Cowican Bay , vancouver island
Im sure you can but first take into consideration what voltage the LED in the power switch needs .....
Most LED's need a resistor in series with the LED , the value of the resistor is determined by the source voltage and current draw and voltage of the LED ..
On your PSU board there is a resistor in series with where the LED goes , this resistor drops the PSU voltage down to about 1.5V as most standard LED's run at 1.5V , the LED in your power switch probably expects 12v DC and has a resistor in series with its LED built in .....
So what you might have to do is adjust the value of the LED resistor on the PSU board or else your LED in the power switch might not light up .....

Cheers
  Reply With Quote
Old 20th August 2013, 08:27 PM   #3
diyAudio Member
 
Join Date: Dec 2012
Location: The Jurassic Coast, England. GB
Send a message via Skype™ to JonSnell Electronic
If the LED is totally isolated from every connection on the switch, I would think so.
Please take notice of Minion's wise words!
__________________
www.flyingmole.co.uk For World Wide support for Flying Mole, Class D, Refurbishment and Repairs. www.jonsnell.co.uk
  Reply With Quote
Old 20th August 2013, 09:25 PM   #4
diyAudio Member
 
lanchile's Avatar
 
Join Date: Sep 2008
Location: AREA 51
one way is this: AC-LED
__________________
Make it simple...Make it better!
  Reply With Quote
Old 20th August 2013, 09:27 PM   #5
davym is offline davym  Scotland
diyAudio Member
 
Join Date: Jul 2013
Location: Under a cloud
Thanks folks, the switch led is isolated but rated 6v. I've sent an email to chipamp, hopefully they will tell me what value resistor I need for the board, that's if I can do it at all and they reply.

Cheers

Davy
  Reply With Quote
Old 20th August 2013, 09:42 PM   #6
davym is offline davym  Scotland
diyAudio Member
 
Join Date: Jul 2013
Location: Under a cloud
Quote:
Originally Posted by lanchile View Post
one way is this: AC-LED
Cheers i'll check that out.

Originally I was going to tap the roughly 30v DC from one rail using a couple of 2W resistors the seller sent me but I came across a picture of a chipamp in which the builder had substituted the led on the board for the one in his switch, cant remember who built that amp but I think i have a copy of the picture.

Last edited by davym; 20th August 2013 at 09:49 PM.
  Reply With Quote
Old 20th August 2013, 09:42 PM   #7
diyAudio Member
 
sofaspud's Avatar
 
Join Date: Nov 2005
Location: San Antonio
I assume the purpose is to indicate that the PSU is working (well enough to light the LED)? Otherwise the LED connection point on the PSU board could likely be left empty, or stuffed with the LED flush to the board and hidden inside the enclosure. The mains switch LED continues as the power-on indicator.
__________________
It is error only, and not truth, that shrinks from enquiry. - Thomas Paine
  Reply With Quote
Old 20th August 2013, 09:45 PM   #8
diyAudio Member
 
Join Date: Dec 2012
Location: The Jurassic Coast, England. GB
Send a message via Skype™ to JonSnell Electronic
Your LED will be happy with between 10 amd 20mAmps, so choose your series resistor dependant on the voltage.
If it is to run from a 30volt rail, 2k7 ˝Watt would be ideal
__________________
www.flyingmole.co.uk For World Wide support for Flying Mole, Class D, Refurbishment and Repairs. www.jonsnell.co.uk
  Reply With Quote
Old 20th August 2013, 09:53 PM   #9
davym is offline davym  Scotland
diyAudio Member
 
Join Date: Jul 2013
Location: Under a cloud
Click the image to open in full size.

Cheers Jon, thought the ones he sent were a bit on the large side for 30v.

Above is the build which gave me the idea about substituting the board led for the power switch indicator one. It would be neat if i could do the same thing.

btw my build will be very similar to this using a shielded transformer and the same case except i got them to cut the power socket hole in the middle of the rear panel and i wont be fitting the volume pot.

Last edited by davym; 20th August 2013 at 09:59 PM.
  Reply With Quote
Old 20th August 2013, 11:17 PM   #10
davym is offline davym  Scotland
diyAudio Member
 
Join Date: Jul 2013
Location: Under a cloud
Quote:
Originally Posted by JonSnell Electronic View Post
Your LED will be happy with between 10 amd 20mAmps, so choose your series resistor dependant on the voltage.
If it is to run from a 30volt rail, 2k7 ˝Watt would be ideal
Hi Jon, can I just confirm that 2k7 would be ok? the led indicator terminal input is 6v.

The supplier sent 2 x 4.6k 2 watt resistors with their legs twisted together giving me a reading of 2.2k, I know they are a bit large in wattage but would they be close enough for 6v?

Cheers

Davy
  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
CRC Chipamp psu 6L6 Chip Amps 16 20th February 2012 04:02 AM
PSU for preamp and chipamp kikikaka Power Supplies 9 23rd December 2011 04:53 PM
LED Pushbutton hookup to chipamp problem JohnnyP00 Chip Amps 8 21st February 2010 09:48 PM
chipamp PSU problem, need help sith Chip Amps 12 3rd March 2006 04:40 PM
LM1875 Chipamp PSU. Metallica Chip Amps 6 3rd February 2006 05:38 PM


New To Site? Need Help?

All times are GMT. The time now is 11:30 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