madbeanpedals::forum

Projects => Tech Help - Projects Page => Topic started by: pryde on November 13, 2011, 10:52:32 PM

Title: 9v dc adapter question
Post by: pryde on November 13, 2011, 10:52:32 PM
Hello all,

Excuse the newb question but I am building the PCB test rig as seen here:
http://www.madbeanpedals.com/forum/index.php?topic=1140.0

i don't have the the same 9v DC adapter on hand (the black round one with 3 solder points) but was wondering if a basic radio shack one would work as long as it is 2.1 mm inside diameter? I noticed that this one only has 2 solder points though:
http://www.radioshack.com/product/index.jsp?productId=2102486

Thanks for any advice
pryde
Title: Re: 9v dc adapter question
Post by: sgmezei on November 14, 2011, 12:04:19 AM
Yes it should. The third tab tab is for battery power. Take a look at Madbeans general wiring schematic on the project page.

Happy building! Jacob's testing rig is great.
Title: Re: 9v dc adapter question
Post by: mgwhit on November 14, 2011, 12:05:34 AM
The third lug on a DC adapter jack is typically switched so that you can wire up a battery to it.  You probably don't need this in a test rig.  (If you feel like you do, you can wire up a battery adapter externally using a 9V battery connector and a 2.1mm plug.)

The potential problem with that metal Radio Shack plug is that it will probably short to the enclosure -- assuming you're using an aluminum (and not plastic) enclosure.

Title: Re: 9v dc adapter question
Post by: pryde on November 14, 2011, 03:28:02 AM
Thanks for the replys fellas

After posting I realized that the metal jack might short out as I am using an aluminum enclosure. I went ahead and ordered some correct, plastic DC jacks from PPP so I will just wait it out.

-pryde