dumb question on wiring a DC jack

[mordechai]

For the first time I'm using a small panel mount 9v DC jack with only two leads.  One is longer, the other is shorter.  Which one should I wire to the power pad on the board, and which one should be wired to GND?

[antonis]

Multimeter will show you..

[vigilante397]

Agreed, hard to go wrong with a multimeter.

But do you have a picture of it? Different companies may do it differently.

[Aph]

Yes, as Antonis alluded to... Don't take a chance. Plug your power supply into the jack and measure the voltage (polarity) on the two pins.

[mordechai]

I'll use my multimeter...but in the interim, here's the jack.  I'm sure you've seen it before and probably know exactly what is what on here!

https://ae01.alicdn.com/kf/HTB1TJNqMXXXXXa3XXXXq6xXFXXXW/10pcs-lot-Copper-5-5mm-x-2-1mm-DC-Power-Jack-Socket-Female-Panel-Mount-plug.jpg_640x640.jpg

[Aph]

Yes, I have some. On mine, the long lead is positive. But I measure every jack I use... could be shorted, etc.
(I actually test every part that I can)
By the way... don't spend too much time soldering wires to this jack. They can't stand heat at all. I've ruined more than one.

[duck_arse]

if you plug a plug in while you solder, the heat will be carried away a little more effectively and the contacts should stay where they are meant to be.

[EBK]

if you plug a plug in while you solder, the heat will be carried away a little more effectively and the contacts should stay where they are meant to be.

But don't plug the other end into an active power source.  Did I need to say that?  I would hope not. 

[bool]

FIRST decide on which standard to use: center-positive or center-negative?

THEN measure to be sure.


(Iow, as Sex Pistols so eloquently elaborated; "never trust a hippy").

[Aph]

if you plug a plug in while you solder, the heat will be carried away a little more effectively and the contacts should stay where they are meant to be.

Or, is it because I use this?

[PRR]

> because I use this?

That's shiny. You never even plugged it in. Compare mine:

[thermionix]

^ That's just a regular soldering iron, in the Maine winter.