Regarding Tips and Tricks Thread - Tip #7 is Incorrect

Thread Starter


Joined May 28, 2009
CORRECTION: Tip #7 is Incorrect. Edit will not allow me to fix the title. Mod: Done.

If you hook up the 9V snap connector to the power supply as shown, it will be reverse-polarity when connecting it to another 9V snap.
At the power supply end, put the BLACK wire on the POSITIVE terminal, and the RED wire on the NEGATIVE terminal so the small round terminal will have a positive voltage and the other terminal will be negative.
ALWAYS verify polarity with a multi-meter before connecting to something that may be damaged from reverse polarity.

To protect against reverse polarity, use a bridge rectifier module. Connect your device to the + and - of the bridge respectively. Now, it will not matter what polarity is fed to the AC pins of the diode bridge. Since there will be two forward-biased diodes, the output will always be correct with a drop of around 1.4 volts or so.


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Joined Apr 5, 2008

@radiohead , You are correct. When two battery connectors are mounted together, the leads will get twisted.
To do something like this I use a depleted battery of wich I use the top to make the connection.



Joined Oct 29, 2009
I wouldn't worry about it. Looks like a lot of nonsense in that thread. #7 was posted by a user I have never seen.

Frankly it doesn't even make any sense. I am not sure what it is referring too. I think it is supposed to be some kind of joke.

If it bothers you that much PM the poster. Looks like poster has been on recently though I don't ever recall seeing a post.


Joined Jan 29, 2010
I 'think' what the author of this post was trying to say is:
Don't extend the power leads from a project with this button type connector by using an identical type of connector, as the polarity of the wires will have been reversed.

I would say the way its written is ambiguous, I will check what we can do to clarify the desciption


MOD Note:
Added a Cautionary warning, to alert anyone reading Tips Post #7.
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