a 12v amp, looking for chip - Page 5 - 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 9th October 2012, 05:43 PM   #41
Kitax is offline Kitax  Latvia
diyAudio Member
 
Join Date: Sep 2012
Location: Riga
if i put 12 volts to it... i could turn it on and it would still char ge the batterry, wouldent it?
  Reply With Quote
Old 9th October 2012, 07:48 PM   #42
diyAudio Member
 
Join Date: Feb 2011
correct.
  Reply With Quote
Old 11th October 2012, 01:04 PM   #43
Kitax is offline Kitax  Latvia
diyAudio Member
 
Join Date: Sep 2012
Location: Riga
well then thats what i need to do...

also... how easy it is to brake a stereo potentiometer?
  Reply With Quote
Old 11th October 2012, 02:52 PM   #44
diyAudio Member
 
Join Date: Feb 2011
the most common is burning them while soldering.
I must allso warn you that log. potmeters have to be connected properly in order to work as expected, while linear ones do not care. Log ones could be connected in "reverse" mode yielding a verry aggressive volume controll that is utterly useless.
use a linear one.
and solder 1 lead at a time, then let it cool off.
Use aome sortha alligator clip on the lead as a heatsink while soldering to avoid melting the thing.
same applys to the IC too.
listen to bob marley while soldering.
Bob Marley - easy skanking + lyrics - YouTube
no need to rush.
make sure You do use star grounding scheme.
make sure You use a 10 ohm resistor between signal and power ground.
No way You can mess it up.
  Reply With Quote
Old 12th October 2012, 09:51 AM   #45
Kitax is offline Kitax  Latvia
diyAudio Member
 
Join Date: Sep 2012
Location: Riga
oh ok... thanks for the advice... why the 10ohm rezistor?

i guess i'll just have to get a new stereo potentiometer
  Reply With Quote
Old 12th October 2012, 01:49 PM   #46
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
the 10r is an option.
It can be 100r or 1r0 or any where in between. You can even try using a 0r0 link.
The really important point is that Signal Ground and the signal circuit is now separated from the Power Ground and the currents circulating in the power circuits, particularly the smoothing capacitance charging circuit.

If you use a resistor, consider what happens if the equipment connected to the signal input goes faulty. Where does the fault current want to go?
Could that fault current burn out the resistor?

If that resistor burns out, will the equipment remain faulty and the fuses don't blow and some external metal part is now at mains voltage !

Parallel the 10r or what ever you choose, with a pair of inverse parallel power diodes. 1n400x may be sufficient to blow the fuse in very low powered auxiliary equipment.
__________________
regards Andrew T.

Last edited by AndrewT; 12th October 2012 at 01:52 PM.
  Reply With Quote
Old 13th October 2012, 07:08 AM   #47
Kitax is offline Kitax  Latvia
diyAudio Member
 
Join Date: Sep 2012
Location: Riga
so its basically just for safety... :P thanks
  Reply With Quote
Old 13th October 2012, 09:53 AM   #48
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
The resistor is for audio, by reducing circulating currents due to hum fields
The diodes are for safety and only safety. They pass fault current (very unlikely scenario, but only costs 2pence/3cents) to main audio ground and thence to chassis to finally go out thro' PE.
__________________
regards Andrew T.
  Reply With Quote
Old 13th October 2012, 07:44 PM   #49
diyAudio Member
 
Join Date: Feb 2011
part of me says it is too unlikely to happen,
but my common sense tells me You should stick with AndrewT advice.
//worth reading his posts. i done a part of it, verry clever.//
  Reply With Quote
Old 14th October 2012, 08:45 AM   #50
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
ClassII equipment does not have PE protection.
If they have an internal fault, there is no way for the missing PE to blow the Mains fuse.

If a ClassI piece of equipment is connected, then the PE inside that protected equipment can blow the mains fuse in the faulty ClassII equipment when the mains electricity tries to leak out through the interconnects.
__________________
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
12V chip amp distortion maylar Chip Amps 8 11th September 2012 06:22 PM
FS: TDA1562Q 70W 12V chip amp ICs len_scanlan Swap Meet 1 12th June 2012 12:27 AM
chip amp 12V-18V srinath Chip Amps 4 10th March 2010 04:12 AM
Which chip for 12V subwoofer amp chr_madsen Chip Amps 11 1st January 2010 02:34 PM
how the best chip amp for 12V ? dito Chip Amps 5 29th October 2005 02:22 AM


New To Site? Need Help?

All times are GMT. The time now is 02:36 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