Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Parts Where to get, and how to make the best bits. PCB's, caps, transformers, etc.

+8V unregulated?
+8V unregulated?
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 15th February 2008, 05:32 AM   #1
PhantomBox is offline PhantomBox  Venezuela
diyAudio Member
Join Date: Jan 2008
Default +8V unregulated?

Hello there.
Someone gave me a couple of Sony MXP-3000 module in order tho get them racked.
I'm starting whith the PSU for these modules, and found something that I don't quite understand.
It may sound stupid to you, but - as far as I can remember - I've nerver seen this term on any schematic diagram or even printed on a motherboard before and I have turned quite some high-end consoles into rackunits.

Here it is: What exactly does "+8V unreg(ulated)" mean?
(on the motherboard it says +48V, +18V, AUDIO GND, -18V, +24V, PERIPH GND, CHASSIS GND, +8V UNREG and DIGITAL GND, I might use +48V, +18V, -18V, +24V and just a general GND)

  Reply With Quote
Old 15th February 2008, 10:08 PM   #2
dave_gerecke is offline dave_gerecke  United States
diyAudio Member
Join Date: Dec 2007
Location: Phoenix, AZ
Hello PhantomBox, I would think the meaning is that it is a 8VDC power supply without any active device like a pass transistor or voltage regulator (LM317, etc.) in the path from the rectifier and filter capacitors to the terminal on the board. From the sounds of the labelling, the rest of the power lines going to the board have some sort of regulation to maintain the voltage going into terminal at the voltage specified. For some reason the 8VDC line doesn't need to be regulated. Perhaps the regulator is somewhere on the PCB that the wire attachs to. To get a voltage of this value, the transformer would have an AC voltage of around 6 volt AC on the secondary. This is a little high in voltage, but since there is some voltage drop across the diodes in the rectifier, this will bring the voltage down to the 8 volt dc range after rectification and filtering.

Hope this helps,

  Reply With Quote


+8V unregulated?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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
HF noise on unregulated PSU - help! cuibono Power Supplies 6 12th April 2009 08:36 PM
Unregulated PSU MarcH Solid State 8 8th June 2008 09:35 AM
unregulated A75 front end MEGA_amp Pass Labs 1 23rd December 2006 05:31 AM
regulated or unregulated amp anton Car Audio 7 1st July 2006 09:06 PM
unregulated ps for zen v4 boris b Pass Labs 2 17th September 2002 06:34 AM

New To Site? Need Help?

All times are GMT. The time now is 07:02 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 16.67%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio