Tda1541 - volt problems - diyAudio
Go Back   Home > Forums > Source & Line > Digital Line Level
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Digital Line Level DACs, Digital Crossovers, Equalizers, etc.

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 March 2015, 10:17 PM   #1
Green77 is offline Green77  Sweden
diyAudio Member
 
Join Date: May 2007
Location: MJOLBY
Default Tda1541 - volt problems

Hi all!

Just finished a own pcb for this dac chip.

When the td1541 is not in the sockel i can trim in +5 v, -5v and -15v,
But when i put the tda chip in +5v is ok. But -5 and -15 drops to -2 and -6 volt...

Cant find the problem. Anyone?

Best Regards //Daniel
  Reply With Quote
Old 20th March 2015, 10:26 PM   #2
RS232 is offline RS232  United Kingdom
diyAudio Member
 
Join Date: Jan 2006
Location: Swindon
Can you post schematic ?
Is the TDA1541 an original ?
More information please

Ric

Last edited by RS232; 20th March 2015 at 10:28 PM.
  Reply With Quote
Old 20th March 2015, 10:55 PM   #3
Green77 is offline Green77  Sweden
diyAudio Member
 
Join Date: May 2007
Location: MJOLBY
Sorry, i haven't the possiblity to scan it tonight.

It feed from diods and caps to two lm337 for each - volt.
When power is off i get "beep" to pin to on lm337. That is ok.
But when power is on i get beep to ground on pin 1,2 and 3..
I cant find it...getting mad!
  Reply With Quote
Old 21st March 2015, 02:48 PM   #4
RS232 is offline RS232  United Kingdom
diyAudio Member
 
Join Date: Jan 2006
Location: Swindon
You probably have a fake 1541
Where did you get it from ?
  Reply With Quote
Old 21st March 2015, 03:14 PM   #5
Green77 is offline Green77  Sweden
diyAudio Member
 
Join Date: May 2007
Location: MJOLBY
Hello.

No, i have 2 diffrent. Both working in my eBay pcb dac.

I tried to disconnect -5v but -15 still dropped to -6v. And if i disconnect -15v the -5 still drops to -2...
I tried to feed the tda1541 directly from lm337 with wires but voltage dropped.
Without the dac chip in place i can adjust just fine.

Regards //Daniel
  Reply With Quote
Old 21st March 2015, 05:48 PM   #6
poynton is offline poynton  United Kingdom
diyAudio Member
 
poynton's Avatar
 
Join Date: Mar 2005
Location: UK
What is the input voltage ?

Have you connected the LM337s correctly ?

Are the LM337s the correct amperage rating ?


Andy
__________________
If it ain't broke, break it !! Then fix it again. It's called DIY !
  Reply With Quote
Old 21st March 2015, 05:55 PM   #7
Green77 is offline Green77  Sweden
diyAudio Member
 
Join Date: May 2007
Location: MJOLBY
Hello

Input volt is 22 volt on both from same set of diods/caps.
Both 337 is to-220 1amp.
Pin 1 adj
Pin 2 input
Pin 3 out

Best Regards //Daniel
  Reply With Quote
Old 22nd March 2015, 12:12 PM   #8
Green77 is offline Green77  Sweden
diyAudio Member
 
Join Date: May 2007
Location: MJOLBY
Hello

Here is the scematic:

Click the image to open in full size.

Very basic. When the TDA1541 not is installed everything works and i can adjust.
When it's installed i can stil adjust but the voltage dropped to -2 and -6 volt (max).

Here is the pcb:

Click the image to open in full size.

Some parts are SMD under the card (TL431 and some caps/resistors)

Yesterday i bended pin 15 and 26 on the TDA1541 out of the sockel, liftet L3 and L6 and solder wires directly to the pins between them. Didn't work, still the voltage dropped.

Could it be something after the TDA1541 that is wrong? Because it works when the chip is not installed...

Best regards//Daniel

Last edited by Green77; 22nd March 2015 at 12:15 PM.
  Reply With Quote
Old 22nd March 2015, 06:23 PM   #9
Ben Mah is online now Ben Mah  Canada
diyAudio Member
 
Join Date: May 2012
Location: Vancouver
Have you checked the power supplies (-5v, -15v) with test loads?

According to the tda1541a data sheet, the -5v current demand is about 50mA and the -15v current demand is about 35mA. For the -5v supply, a 5v/.050A=100 ohm test load resistor, power is 5v x .050A=.25W, so a 2 watt resistor should be more than adequate. Similar calculations for the -15v supply.

The drop in voltage under load is a sign of too much current draw or your power supply cannot meet the current demand. You should test the power supplies with dummy resistor loads before using them to power your dac chip.

What is the voltage before the LM337, and after the LM337? The voltage before should be a few volts higher than the voltage after and the voltage after should be higher than the design output voltage. The 10 ohm resistor between the LM337 and the Tl431 looks a bit small. That resistor is used to drop the voltage between the LM337 and the TL431.

All voltages should be taken with the test loads in place. If you get the same low voltages with the test loads, then there are problems with your power supply.
  Reply With Quote
Old 22nd March 2015, 06:46 PM   #10
Ben Mah is online now Ben Mah  Canada
diyAudio Member
 
Join Date: May 2012
Location: Vancouver
Quote:
Originally Posted by Green77 View Post


Yesterday i bended pin 15 and 26 on the TDA1541 out of the sockel, liftet L3 and L6 and solder wires directly to the pins between them. Didn't work, still the voltage dropped.

Could it be something after the TDA1541 that is wrong? Because it works when the chip is not installed...
If the power supplies check out with test loads (without the dac chip installed), then there may be something wrong on your board or your dac chip, but if you have tested the chips out on another board, then it is something on your board. Check your components for proper placement, polarity, etc, and check your solder joints for cold joints and unintended bridging/shorts.

Has this particular board been used successfully by others?
  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
CS812 and TDA1541 problems.. Green77 Digital Line Level 4 10th February 2015 05:52 PM
12 volt to 300 volt inverter question for tubes yourownfree Tubes / Valves 93 30th March 2014 04:41 PM
Help converting 13.5 volt ac to 20 volt majod Power Supplies 2 18th December 2013 06:41 AM
Switching 230 Volt Transformer to 120 Volt OMNIFEX Parts 10 6th April 2008 05:34 PM
Problems with piggy backed TDA1541 Dr.H Digital Source 2 24th May 2002 08:30 AM


New To Site? Need Help?

All times are GMT. The time now is 06:12 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.
Copyright 1999-2016 diyAudio

Content Relevant URLs by vBSEO 3.3.2
Wiki