Thanks for the link. That explains it well.

Thanks DAVE,going to use it in my tutorial on mosfets

It's really great to have you guys as advisers! I learn so much in so little time! I'm going to radio shack right now after a busy day.

ELEFEGE WE are all here to give good advice,and with your design you will help us in your ideas too.

Thats what i see great about this forum others helping others to make a good robot design

Hello guys ! Ok, well I think it is fair to say that I have done a good job thanks to your advices. I have a new question but first I want to let you know how my Hybride customized Rovio is doing : It works and safeties work too. I have overall 3 different batteries, one is kicking in automatically only if the two others fail and if this happens I have to quickly return the robot to its charging station because it's a 1amp battery and the robot might easily drain up to 6 amps, 5 for the EZ board + 3 for the rovio itself (it might share something like 1 amp with EZ board since its 3 amp battery is one of the safeties). It has a total of 3 cameras, one has night vision and can be controlled from iPhone, with a built in I/O switch that turns on/off the rovio. This camera itself is turned On/Off by the relay + transistor that I could set thanks to your advices (for some reasons I could never get the mofset to act as a switch... I gave up since I have largely enough amps to support a little 5v relay). NEW ! Today I installed an arm that I customized so the wrist can turn on itself. I'll post a video on youtube very soon so you'll be able to see whole thing at work, I just need to convince my wife to film it while I maneuver from my computer and my iphone. I still need to find out if there's a way to make a circuit that would prevent current from backdrafting into the rovio from EZB since its two main motors are still connected through both EZB and Original's Rovio controllers. and it really does not like it, I'm even surprised it didn't burn out yet!

Elfege