another 220v to 110v question - diyAudio
Go Back   Home > Forums > Design & Build > Parts

Parts Where to get, and how to make the best bits. PCB's, caps, transformers, 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 19th August 2003, 12:36 AM   #1
diyAudio Member
 
Join Date: Aug 2003
Location: Dallas TX
Default another 220v to 110v question

I found the exact opposite of what I'm trying to accomplish through the search function, but it helped nonetheless.

Help: conversion from 110v to 220v

The unit is a Bose 901 equalizer from 1993 and I had Bose rewire it from 110v to 220v and now I want to change it back. It uses a (Markings: Pikatron D 6390 USINGEN NP 1076 QV 120993) transformer that currently is wired (on the primary) to the incoming wires on its outside taps and the 2 inside ones are shorted to create a series connection. It leads me to believe I have 2 equal windings together handling the 220v.

My question is: Can I disconnect the series connector and wire the 2 primary windings in parallel - to get it back to 110v operation? or is that a bad assumption? are there any gotcha's in phasing etc.?

sorry, i'm a rank amateur and it's been 20+ years since I've done this..I could of course send it back to Bose but on principle and pride feel I've already paid once to do this and I should be able to do it myself...
  Reply With Quote
Old 19th August 2003, 07:51 AM   #2
trwh is offline trwh  United Kingdom
diyAudio Member
 
trwh's Avatar
 
Join Date: Apr 2002
Location: UK
Hi

You're quite right in saying you should be able to connect the primaries in parallel for 110V operation. Again, you are also right in assuming there are gotcha's with phasing! You must make sure that the beginning and end of the two windings are connected together, not vice versa. This should be quite simple since you already have them wired in series - the end of one winding will currently be connected to the beginning of the next, so you can work out what connection you need.

There may also be a mains fuse value to change. If this is so, it would involve a current rating increase. Try and determine what the present value of the fuse rating is and see if it's appropriate for the power drawn by the unit for 110V operation.

Take care,
Tim.

PS - Maybe Bose could provide a service manual that would help?

EDIT: Just so I'm clear, I mean both the winding beginnings and both the winding ends connected.
  Reply With Quote
Old 19th August 2003, 08:14 AM   #3
dhaen is offline dhaen  Europe
diyAudio Moderator Emeritus
 
dhaen's Avatar
 
Join Date: Jun 2002
Location: U.K.
Hi,

Your assumption is correct. The phasing of the windings is of course vitaly important, but easily determined by deduction:
Lets call these primaries winding A and winding B.
At present, one end of winding A is connected to one end of winding B.
Disconnect that end of winding A, and connect it to the other end of winding B.
The 2 remaining winding ends can then be connected.

Clear as mud?

Cheers,
  Reply With Quote
Old 19th August 2003, 09:54 AM   #4
moamps is offline moamps  Croatia
diyAudio Member
 
Join Date: Oct 2002
Location: Croatia
1 picture>=100 words
Attached Images
File Type: jpg 115230.jpg (15.1 KB, 213 views)
  Reply With Quote
Old 19th August 2003, 10:08 AM   #5
dhaen is offline dhaen  Europe
diyAudio Moderator Emeritus
 
dhaen's Avatar
 
Join Date: Jun 2002
Location: U.K.
Thanks Moamps
  Reply With Quote
Old 19th August 2003, 01:01 PM   #6
diyAudio Member
 
Join Date: Aug 2003
Location: Dallas TX
Very clear, and extremely gracious of you all. thanks.
  Reply With Quote
Old 20th August 2003, 03:21 AM   #7
diyAudio Member
 
Join Date: Aug 2003
Location: Dallas TX
worked, I now have a 110v equalizer. thanks.
  Reply With Quote
Old 11th July 2010, 09:11 PM   #8
diyAudio Member
 
Join Date: Jul 2010
Thanks for the advice. I just converted my Bose 901 Series VI equalizer from 220V to 110V. Here are some specifics. Next to the primary of the transformer (the side where the power cord is soldered), there are three places for jumpers. For 220 volt operation, the one labeled LK1 is installed. To convert to 110 volt operation, remove the LK1 jumper. There are two spots (without jumpers in them, but with lines indicating there could be one) labeled 1-2 and 3-4. Next solder a jumper from hole 1 to hole 2, and a second jumper from hole 3 to hole 4.

I tested mine by checking voltage at testpoints indicated on the PCB for GND, +15V and -15V (located in the area behind the switches).

Hope this helps someone.

Al
  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
110v or 220v, how can you tell? fjmart134 Tubes / Valves 2 8th June 2009 10:18 PM
AR XA 220V to 110V dan duette Analogue Source 2 13th February 2009 01:08 PM
Simple question regarding converting chipamp from 110V to 220V maurycy Chip Amps 16 8th December 2008 11:58 PM
How to convert 220V to 110V??? Real Prober Digital Source 4 5th November 2004 07:02 AM
Help: conversion from 110v to 220v Russell Sit Solid State 13 5th December 2002 08:28 AM


New To Site? Need Help?

All times are GMT. The time now is 10:39 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