JM-1
Joined: 30/09/07
Posts: 604
|
Reversing polarity of DC power supply
#966956 - 28/01/12 05:54 PM
|
|
|
I need an 18volt DC regulated power supply and the only one I can find is unfortunately
the wrong polarity (i.e. centre positive).
http://www.ebay.co.uk/itm/18-Volt-DC-Power-Supply-18v-Regulated-PSU-5-5mm-
x-2-1mm-/300366802276?pt=UK_Computing_PowerSupplies_EH&hash=item45ef41ad64#ht_1820wt_1
187
Obviously I could cut the wires and swap them around - but might
there be a more elegant alternative?
The seller is concerned that it might
not work for my purposes, being 'switched mode' - apparently it should be 'linear'. Does
this matter?
Edited by Jay Menon (28/01/12 06:11 PM)
|
Folderol
Joined: 15/11/08
Posts: 2542
Loc: Rochester, UK
|
Re: Reversing polarity of DC power supply
[Re: JM-1]
#966957 - 28/01/12 06:31 PM
|
|
|
|
Depends entirely on what it is powering!
Are you sure it's just a straight 18V
DC? i.e. not +9 & -9. For lightweight steady-state kit it won't make a lot of
difference as to linear or switch mode, although poor quality ones can generate quite a
bit of noise.
I haven't looked recently, but there always used to be a bunch of
switchable mulit-voltage PSU with switchable polarity.
--------------------
It wasn't me!
(Well, actually, it probably was)
|
DGL.
Joined: 28/10/11
Posts: 238
|
Re: Reversing polarity of DC power supply
[Re: JM-1]
#966964 - 28/01/12 07:29 PM
|
|
|
|
You could cut the end off and solder a new end on, that would be quite neat or (if you
know what you are doing) open up the psu and swap inside.
|
ef37a
Joined: 29/05/06
Posts: 5619
Loc: northampton uk
|
Re: Reversing polarity of DC power supply
[Re: JM-1]
#967013 - 29/01/12 08:21 AM
|
|
|
|
Don't know quite why swopping plugs on a PSU should be "inelegant" Jay? Maybe I am some
kind of Philistine!
Anyhooosy! Buy the supply and drag it to Maplins (or buy
one there!) where you will find power conn' line sockets. Buy one and a plug to suit and
make up a reversing adaptor.
Yonks ago I got hissed off with the odd
collection of pedals etc son had so I standardized on a PSU with a female RCA out and made
up various leads to suite.
Err? Maybe we should not suggest that noob
electrical people (no offense Jay)open up sealed mains kit?
Dave.
Edited by ef37a (29/01/12 08:23 AM)
|
DGL.
Joined: 28/10/11
Posts: 238
|
Re: Reversing polarity of DC power supply
[Re: ef37a]
#967017 - 29/01/12 09:59 AM
|
|
|
|
I did say 'if they knew what they were doing'. if you have never opened up a psu before
DON'T.
|
ef37a
Joined: 29/05/06
Posts: 5619
Loc: northampton uk
|
Re: Reversing polarity of DC power supply
[Re: DGL.]
#967021 - 29/01/12 10:18 AM
|
|
|
Quote DGL.:
I did say 'if they
knew what they were doing'. if you have never opened up a psu before DON'T.
Fair enough DGL.
Dave.
|
JM-1
Joined: 30/09/07
Posts: 604
|
Re: Reversing polarity of DC power supply
[Re: JM-1]
#967041 - 29/01/12 12:17 PM
|
|
|
I'm thoroughly enjoying this...! and no offence taken to anything here. Often
the adapter at the end is a sealed unit - and a pain to open up. It would be far simpler
to cut the wire proximal to it, peel the insulation back, wrap the wires together and
shield with insulation tape... I hear groans of horror... 
|
ef37a
Joined: 29/05/06
Posts: 5619
Loc: northampton uk
|
Re: Reversing polarity of DC power supply
[Re: JM-1]
#967044 - 29/01/12 12:37 PM
|
|
|
Quote Jay Menon:
I'm thoroughly
enjoying this...! and no offence taken to anything here.
Often the adapter at
the end is a sealed unit - and a pain to open up. It would be far simpler to cut the wire
proximal to it, peel the insulation back, wrap the wires together and shield with
insulation tape...
I hear groans of horror...
Oh FFS! If you are going to cut wires
fit a proper plug!
Dave.
|
JM-1
Joined: 30/09/07
Posts: 604
|
Re: Reversing polarity of DC power supply
[Re: JM-1]
#967049 - 29/01/12 12:57 PM
|
|
|
|
See...I'm a prophet - hear the first groans!
|
Folderol
Joined: 15/11/08
Posts: 2542
Loc: Rochester, UK
|
Re: Reversing polarity of DC power supply
[Re: JM-1]
#967073 - 29/01/12 03:00 PM
|
|
|
Quote Jay Menon:
See...I'm a
prophet - hear the first groans!
I
bet you were one of those kids that pulled the wings off flies.
--------------------
It wasn't me!
(Well, actually, it probably was)
|
grab
Joined: 08/07/07
Posts: 2626
Loc: Cambridge, UK
|
Re: Reversing polarity of DC power supply
[Re: JM-1]
#967193 - 30/01/12 10:26 AM
|
|
|
|
grab
Joined: 08/07/07
Posts: 2626
Loc: Cambridge, UK
|
Re: Reversing polarity of DC power supply
[Re: JM-1]
#967194 - 30/01/12 10:28 AM
|
|
|
Oh, and I typed "18V regulated power supply" into Google and got a whole bunch of places
selling them. In the UK:
http://www.effectpowersupplies.com/18v-dc-regulated-power-supply-7-p.asp
who will do it with either polarity.
|
ef37a
Joined: 29/05/06
Posts: 5619
Loc: northampton uk
|
Re: Reversing polarity of DC power supply
[Re: grab]
#967197 - 30/01/12 10:38 AM
|
|
|
Quote grab:
Oh, and I typed "18V
regulated power supply" into Google and got a whole bunch of places selling them. In the
UK:
http://www.effectpowersupplies.com/18v-dc-regulated-power-supply-7-p.asp
who will do it with either polarity.
That looks a sturdy unit Grab and not too cheap. I do wish
however that all wall rats had the exit lead OPPOSITE the earth pin and not by it!
Better still if they had a power socket and a plug to plug lead, then you could
order a pair of both "hands" and make them up in lengths to suit the situation!
Dave.
|
Previous
Topics
Next
Threaded
Edit
Reply
Quote
