Originally Posted by Green-dot
how much transmitting power (radiated field emission) would be required to make a 28 Vdc relay move from run to cutoff position?
The question is not well formulated.
The transmitting power would be dependent on how far away the transmitter is (inverse-square law and all that) and whether the transmitter is broadcast or directed-energy.
One needs to know how much energy is required to move the relay. This is not dependent merely on the voltage rating of the part, but on its specific design and manufacture and that of the system of which it is part. Then you have to guess what kind of transmitter you want to know about and where it might have been. Then you can figure out how much power it would have needed.
And then you have to figure out how it might actually achieve the action proposed. It is obviously not sufficient just to put the right amount of energy there - one needs to suggest a causal mechanism.
PBL