Convention on +ve/-ve connections on accessory power tips?

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Toubab
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I've taken some kit out of the Landrover and need to install in into the Landcruiser....but being a bit of a knobend, I forgot to label up the wiring (it was dark and pissing down :blush)

So I've got a rather small (3mm I'd guess) power tip and I'm not sure if the outside or inside is +ve....I know they vary a lot 'cos all the 'universal' adapters I have use reversible pins and you have to follow the diagramme to tell you which one is which.



There isn't one of those diagrams on this kit, but there is an arrow on the barrel....

Any ideas ?

I know it's a 12v supply 'cos that's why I cut the ciggy socket plug off to hardwire it- IE it didn't have a transformer circuit in it.

It's a 3 inch colour LCD screen....does it even matter if I get the polarity the wrong way round?? :nenau


I've got a 50/50 chance obviously, but it's an expensive thing to blow up so if anyone has any ideas how to tell, or knows what the arrow means, I'm all ears :thumb2

it's one of these but 3 mm........
20446.jpg



EDIT PS the wire to the tip isn't marked up either, not even a stripe :(
 
TUNED IN said:
as a rule it is positive to the tip on most things
Click to expand...

Mmm yes, and that nakes sense from a safety/blowing fuse design sense, but on the universal adapters, you get to set that by changing it round 180 degrees on te pins so there must be a fair few things out there that are +ve on the outside :nenau
It's a VR3 Monitor- I've looked for diags online but haven't found anything yet :(

b45b4b16-3b05-45e8-88ed-e017b79ddf59_300.jpg
 
I've never seen an plug type adaptor with positive to the outside.... only seen the option in the replacement PSU's
 
I have owned 2 devices that were positive sleeve, and both of them were hard drives. Alas, I used the cable for one in a normally-wired caddy, and the results were rather predictable. I think the rogue cable is festering in the corner of the room behind some shelving now :mad:

The only way to properly tell is to take the lid off and look - any elastictrickery geek would be able to spot which the earth is a mile off.

Isn't there some sort of little circley liney logo on it with a plus and a minus? Although, now I come to think of it - the numpties who wired one of the silly disk caddies the wrong way round didn't put the logo on that either, so I've made up a sticker for the dratted thing, in case I blow it up too :rolleyes:

Edit - I've just added a piccy with a "circley liney logo" so you know WTF I was on about.
 

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Tobermory Womble said:
I have owned 2 devices that were positive sleeve, and both of them were hard drives. Alas, I used the cable for one in a normally-wired caddy, and the results were rather predictable. I think the rogue cable is festering in the corner of the room behind some shelving now :mad:

The only way to properly tell is to take the lid off and look - any elastictrickery geek would be able to spot which the earth is a mile off.

Isn't there some sort of little circley liney logo on it with a plus and a minus? Although, now I come to think of it - the numpties who wired one of the silly disk caddies the wrong way round didn't put the logo on that either, so I've made up a sticker for the dratted thing, in case I blow it up too :rolleyes:

Edit - I've just added a piccy with a "circley liney logo" so you know WTF I was on about.
Click to expand...

That was the diagram I mentioned in the first post...alas there's nothing on the unit itself or the plug....there is a little arrow symbol on the plastic of the barrel of the plug but I have no idea what that signifies :nenau

The inside looks like this.....there is a '+' symbol on the pcb next to the red lead but it's hard to tell which terminal it refers to in the block....
 

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:blast Double knob-end......FFS, I should own a 1200 :blast

Stress over- I'll stick a DMM in continuity mode across the marked +terminal and to the two ends of the flying wire in turn....that'll tell me which should be +ve :thumb2


So fekkin simple :blast :blush
 
Fanum said:
:blast Double knob-end......FFS, I should own a 1200 :blast

Stress over- I'll stick a DMM across the marked +terminal and to the two ends of the flying wire in turn....that'll tell me which should be +ve :thumb2


So fekkin simple :blast :blush
Click to expand...

lucky it was labelled inside... and was the positive the tip?:D
 
TUNED IN said:
lucky it was labelled inside... and was the positive the tip?:D
Click to expand...

I don't think I'll ever know Gary....the socket is too small to get onto the pin or barrel so the only thing I can do with a continuity meter is to measure through from the red lead inside the unit to the end of the lead of the plug- the plug itself is sealed so although I'll be able to identify which one goes to the marked live, I won't know if it's the barrel or pin :)

WTF am I saying :blast

I can measure it on the plug end itself once it's wired up :aidan

the 1200 disease...it's catching :D
 
Sorry I missed the bit about the label - for some reason I stopped scrolling back at post 5 when I was editing :blast

From the layout of the wiring, I'd be willing to bet that that was a positive tip, negative sleeve.

So, is it still a monitor, or a pretty paperweight that smells of burnt epoxy?
 
Tobermory Womble said:
So, is it still a monitor, or a pretty paperweight that smells of burnt epoxy?
Click to expand...

I don't know....my jump start pack with its 12v socket is in the back of the Land Rover on a farm a few miles away and it's raining so I'm not gonna go play with it in the LC now :D

TBC tomorrow ;)
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
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