Switch mode in powered mixer. - diyAudio
Go Back   Home > Forums > Amplifiers > Power Supplies

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 23rd November 2011, 01:22 AM   #1
diyAudio Member
 
Join Date: Apr 2005
Location: Simcoe Ont
Default Switch mode in powered mixer.

I am working on a Powered mixer made by Phonic.
I have no power to preamp or DSP. I followed back to Primary portion of Power supply and found there a 7815 that is getting 120VAC unless I have measured incorrectly. Further, AC1 has 120VAC to chassis and AC2 has .5VAC to chassis.
Any advice would be greatly appreciated.
Thanks
  Reply With Quote
Old 25th November 2011, 04:32 AM   #2
diyAudio Member
 
JOHN BALI's Avatar
 
Join Date: Jun 2010
Location: Near the Mountain
Hi argonrepublic
first I will disconnect all load then measured all voltage output, are they normal?
me or other can help if there any picture of this
  Reply With Quote
Old 25th November 2011, 07:19 AM   #3
diyAudio Member
 
Join Date: Apr 2010
Location: seattle, wa
Assuming you live in an area where line power is 120 ac line to neutral, and neutral is connected to ground, and so is the chassis of your mixer, then your line measurements are what you would expect.

However, do not assume that the chassis is connected to the mixer circuitry. Obviously, 120vac on a 7815 should blow it open/light it on fire, that sort of failure.
  Reply With Quote
Old 25th November 2011, 01:41 PM   #4
diyAudio Member
 
Join Date: Apr 2005
Location: Simcoe Ont
I was kind of thinking that I may be catching the wrong ground. I place neg probe of meter to circuit board and pos to 7815 and did not find less than 120VAC. No signs of damage. At one point I used my hand to slight bend 7815 to gain access and got 120VAC shock from to of 7815 didn't expect that. I will keep looking to find the proper ground.
Attached Images
File Type: jpg Phonic ps.jpg (106.2 KB, 69 views)
  Reply With Quote
Old 25th November 2011, 03:31 PM   #5
diyAudio Member
 
Join Date: Apr 2005
Location: Simcoe Ont
I was able to find a ground to get 15V from 7815. It is on the -output of a rectifier. It appears strange that when I checked the Rectifier, It is showing 27.6VAC and 320VDC. I understood that a rectifier should have more dc coming out than AC going in. What is going on here. What am I missing?
  Reply With Quote
Old 25th November 2011, 05:24 PM   #6
diyAudio Member
 
Join Date: Apr 2005
Location: Simcoe Ont
I have +34VDC-ground and -34VDC on one connector.
On the other, I have 12VDC and ground.
I have been able to determine beyond doubt that I am missing +/-15VDC for TL074s as well as dsp on preamp board witch was my original concern. Please advise me what to look for. I cannot see the forest through the trees. I have no schematics and there are no obvious 7815 and 7915 regulator that I am accustomed to seeing on this type of system.
Thanks
  Reply With Quote
Old 25th November 2011, 05:44 PM   #7
diyAudio Member
 
Join Date: Nov 2002
Quote:
I followed back to Primary portion of Power supply and found there a 7815 that is getting 120VAC


I'm confused here... in the prior post of your you said there is a 7815 getting 120vac then you say I have no schematics and there are no obvious 7815 and 7915 regulator that I am accustomed to seeing on this type of system.

Is there or isn't there a 7815 and 7915 regulator?

Check the TL074's for + and - supply again got to be there but it might be down in the dumps.
  Reply With Quote
Old 25th November 2011, 07:18 PM   #8
diyAudio Member
 
Join Date: Apr 2005
Location: Simcoe Ont
There is a 7815 on the power supply. I am now working on the amplifier board which has a connector that goes to the preamps. Evidently, there is 7815 and 7915. I overlooked them because they were discretely mounted between outputs.
  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
Help to connect powered mixer with amp. Remo Di Solid State 1 9th July 2010 01:31 PM
Passive mixer with powered preamp? VanZea Solid State 4 4th May 2010 04:16 PM
Using a spdt switch to select between triode mode and pentode mode on a guitar amp. G Tubes / Valves 19 15th March 2006 10:15 AM
Powered Mixer Noises guitargully Solid State 0 9th January 2004 10:52 PM


New To Site? Need Help?

All times are GMT. The time now is 12:54 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