extra transistor in level shifter - diyAudio
Go Back   Home > Forums > Amplifiers > Class D
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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
Thread Tools Search this Thread
Old 27th October 2007, 10:14 AM   #1
Join Date: Jan 2005
Default extra transistor in level shifter

What does this NPN transistor do in th level shifter ?

In simulation it doesent do a thing.

  Reply With Quote
Old 27th October 2007, 11:26 AM   #2
Pabo is offline Pabo  Sweden
diyAudio Member
Join Date: Feb 2003
Location: Helsingborg, southern sweden
I think it keeps the LIN input on the driver high during startup which charges the bootstrap capacitor. Will give a large pop noise though so I recommend a relay to the speaker with a few seconds delay.

I am not sure how IRS2011 works but you can try to charge the bootstrap capacitor directly from the positive rail instead with something like 20k or so. Remember to check if the boot strap supply has built in zener protection across it.
If something that measures good doesn´t sound good, measure again!
  Reply With Quote
Old 27th October 2007, 11:30 AM   #3
Eva is offline Eva  Spain
diyAudio Member
Eva's Avatar
Join Date: Oct 2003
Location: Near the sea
Send a message via MSN to Eva
It forces comparator output low for a brief period of time at power up.
I use to feel like the small child in The Emperor's New Clothes tale
  Reply With Quote
Old 27th October 2007, 11:32 AM   #4
Join Date: Jan 2005
Ah ok.

I´m not gonna use it so i hope the amp starts anyways.

Btw 1N4148 is not usable to charge the bootstrap eh ? I figure BYV26-150 is atleast whats needed, right or wrong ?
  Reply With Quote


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
Cassette transcriber into pitch shifter? seilee1 Everything Else 4 11th December 2007 08:50 PM
Cassette transcriber into pitch shifter? seilee1 Analogue Source 0 6th December 2007 03:15 AM
Level Shifter maverick_123 Class D 1 6th November 2007 10:12 PM
lesser of two evils, high level -> line level, digital volume control mazurek Solid State 3 19th November 2006 12:25 AM
how to bring down line level signal to preamplifier level deji Solid State 15 15th April 2004 04:13 PM

New To Site? Need Help?

All times are GMT. The time now is 09:08 PM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2