robot-doc that idea of a IP-SWITCH gives me a idea on how to make a internet control switch for EZB ,once i get back as i have time will look at making a simple design.

Since i am now retired ,i have full time to design circuits for EZB forum and put them up for anyone to use them.

elfage, I don't think that your board is shutting down due to a current spike (at least not in a way that a diode would fix). It sounds as if your motors are drawing too much current and the board is "browning out." They are sucking the power out of the board, and the voltage drops too low for the board to continue to operate. It is designed to run servos, but not too much more than that. I don't understand exactly how you are trying to feed power from the EZ-B into the motors that are powered from a seperate source, but that is not going to work. You can control them with EZ-B through a motor controller, or perhaps a transistor, but you cannot feed power directly from the board to a DC motor. It sounds as if you have your answers on a switch to turn it off and on, but I hope this helps you with your issue of the board dropping out,

FYI i use the servos's circuits to control the motors. The motors are connected to 2 separate sources : one from EZB's and one from their original source...

Another question : shuts down happen also while docking to the charging station (two separate chargers : one for the 6v nimh battery that feeds the rovio, the other for the EZB's 10000 mah lithium battery pack (originately an iphone/ipad/other_devices juice pack, made by Anker)

Thank you again for your kindness. I should definitely have a guy coming to see my work! Anyone in NYC?

I pay the beer!

Here is another idea using a magnet and a reed switch and electronic SPDT switching circuit to turn on a high current mosfet.

Once ii get back with design and make the circuit,it will not use any current in the off mode.

KINDA like a flipflop works apply the magnet is switches on and then to turn it off apply the magnet again next to the REED switch inside the robot.

I'm not too far away; Boston. But, that's still a haul. Can you post pictures of your wiring? Connecting two sources to the motors sounds problematic. Pictures would make it easier to understand than trying to describe it. I won't be back at my computer until tomorrow evening, but between now and then someone will probably have an answer for you. If not, I'll take another crack at it.

Incidently, using a servo like a mechanical switch is not too far fetched. I am working on the same thing myself. Instead of using contacts, I am using micro buttons. I hope to post some video by this weekend.

I just saw your answer, thank you ! I'm doing some research to understand why I'm losing 1 volt with my circuit. It's so sad to be ignorant!

ELFEDE a few post back i posted info on why you are losing 1 volt ,hope this helps you out