12v DC cabling question

[Glandwr]

Hi, I’ve had the 12v power supply for a router pack up. I’ve got a replacement with the same input and output but different adaptor plug.

Fine I thought just cut the old one off and splice it on the new one. So far so good!

However when I cut the old one off there was just one centre cable with fine uninsulated wire around it. I assume the centre one is positive and the sheathing/shielding wire neg. Anyone?

I have not cut the adaptor off the new power supply in case I have to return it. But found a similar looking one in the shed that I think came from an old router as well. That has TOTALLY confused me. That has a twin cables inside the outside sheathing. But each one of those recognisable as pos and neg has an insulated single centre wire surrounded by similar fine uninsulated wire.

Help please. They (Netgear) don’t make that power supply any more.

 

[1 Cup]

Open the old box up. Hammer time
Get a multi meter ! . Most electrical items are 12 volt . I like 5 volt usb.

 

[guerdeval]

Could you not put up a pic of the end of the wire that goes into the router as I for one have a few of these knocking about ,just a thought. This one is on a small laptop for instance.

 

[mistericeman]

There's usually a detail on the label of the,power supply giving output voltage/ connector polarity

 

[Fazerloz]

Usually but not always outer braiding - inner core + check as mistericeman says.

 

[1 Cup]

The box has a sticker should have 3 - so - - - ubove a thick line = dc otherwize
Cut 1 wire to find power +

If its for van why not forget the trans former 240v and just go 12v to 12v .. run of led lights controlled power sauce. Or like me use longer wire to reduce power at other end.from solar controller. 14volts max fan 10m wire 12v

 

[Glandwr]

Thanks for all the suggestions. I was particularly taken with the one that involved a hammer . A micrometer and Ebay came to the rescue in the end. I've identified what I need in this lot for less than £2.50 and as there's no hurry I'll put my feet up.

Universal Laptop Notebook AC DC Power Charger Adapter Socket Plug Connector Tips | eBay

5.5 x 2.1mm Jack to Plugs. Letter G: 4.0 1.7MM. Letter F: 4.8 1.7MM. Letter E: 5.5 1.7MM. Letter D: 5.5 2.1MM. Letter C: 5.5 2.5MM. Letter B: 6.3 3.0MM. Letter A: 6.5 4.4MM with a needle.

www.ebay.co.uk

 

[1 Cup]

So that fits onto standard 2,5 Jack. Nice. I've only seen the 2 pin one's and bang me fitted wrong way round .

Was that right ! . delivery's £15.00 lol .