Re: Wire transmission(15 mtrs) to send data & control signals for cascaded shift regi
MOSFETs come in many shapes and sizes but they are just transistors, they only work as part of a bigger circuit. You would have to show how you think one would work for us to advise you.
As long as you keep the wiring far enough away from a running 3-phase motor it will not cause any problems but if the motor is switched on or off you should expect spikes to corrupt the data. If you use RS422 as we suggested, it will not only make the link immune to interference, it will allow a small difference in ground voltages at each end. RS422 works on the relative voltages across two wires instead of the absolute voltage so it allows an overall shift in ground potentials between the two ends. You can use inexpensive CAT5 cable (network cable) for the link. Look at the data sheets for the ADM488/ADM489 for ideas, they are made by several companies.
Brian.