Stimulator polarity
 

Hey guys,

Have searched - here, google, MS Extra, etc - can't find an answer. :facepalm:

All I need to know is the polarity of the Megasquirt stimulator. Brain has built me a DIYPNP. I can't use the 110v Stim sold by DIY because in Australia we use 240v mains power. I don't want to use a 240v ==> 110v inverter - I've had one catch fire before, not fun. Besides, they are fucking expensive and a 12v DC transformer for 240v is <$10 in Australia.

So someone, anyone, can you tell me whether the (+) is on the inside or outside of the plug on your Stimpower? I do not want to fuck this up and burn out something in my new MS.

Assuming you have an ohmmeter, just measure between a ground pin on the ECU connector and the inside and outside of the power jack on the stim. Whichever shows you zero ohms is where the negative side of the wall wart should be.

Which stim are you using? If it's a Jimstim, here is the page you are looking for:

http://jbperf.com/JimStim/JimStim_v1...bly.html#ready

If it's that other stim DIY sells, it's likely to be the same, but check it via a multimeter as above.

The stim has a connector to hook up wires to marked + and -, yes? It at least has a spot for one. Follow the traces on the back of the board from the positive one to the plug. It should lead to the center pin. At least if it's a V2.21 stim it should.

center pin is positive, outside is negative. The one you linked should be fine, provided the diameter of the plug is correct.

This is good stuff, but I should clarify - I only really need the stimpower - basically, I need a 240v version of this:

http://www.diyautotune.com/catalog/m...ply-p-168.html

My ohmmeter is on the slow boat to Australia along with most of the rest of my tools and other shizz. No big deal though, can't really do much of anything else until it all arrives. I just wanted to play around with the MS in the meantime, get a feel for TS and the settings.

Win! Many thanks.