hi all, i wonder what is the effect of a magnetic field being near the mbed while excuting a program on its memory?? i heard some information (that i'm not sure it is right), that when a microcontroller (a PIC for example) is working near a magnetic field (due to a motor taking high current through wires for istance), the microcontroller starts to act in an unpredictible manner, and i want to make sure whether this piece of information is right or not, and if it is right, i want to know to what extent this affects the mbed.

thank you very much.

Hi Hassan,

I dont think magnetic field will effect the performance of the mbed or even anyother controller. and regarding the info abt PIC controller, probably if the motor is controlled with the PIC itself, it may behave in an odd manner due to improper circuit design.

regards

Unless the magnetic field is extremely high, at which point induction will take place, But that needs an alternating magnetic field.

The normal problem is.back emf, like when the magnetic field.around a relay coil collapses, Especially, without a fly back diode, and possibly a number capacitor. Additionaly, a motor, will .generate a significant amount of very high frequency spikes, Just bring an AM radio close to a cheap motorized toy, and listen for the crackling noise.

A reasonable amount of this can be absorbed, by 3 capacitors, 1 across the motor, and 1 each, from motor terminal, to motor case. AS CLOSE TO MOTOR CASE AS POSSIBLE! Hope this helps Ceri

Yeah, just to echo what the others have said the problem is normally not the magnetic field of the motor but the back EMF it generates