Bear with me.
Using a real proton pack in a lucid dream:
1. I hit the electrical power generator switch on the wand (lower right metal toggle switch). The red light on the wand came on with an audible electric hum.
2. I hit the auxillary systems switch on the wand (upper right metal toggle switch). All the lights, bargraph, etc. came on.
3. I hit activate (lower left metal toggle switch marked "Activate") to activate the cyclotron. The infamous deep bass of the cyclotron firing up was heard.
As soon as the cyclotron fired up, you could feel a slight vibration in the wand. In sync with the cyclotron. I'd guess about 4hz at "idle". Not just a rumble like on a force feedback joypad or on the matty wands. It was more a gyroscopic, straightening type tactile twitch. (Gyroscopic means it exerts a force opposing movement.) More like a magnetic force. Really slight. In sync with the cyclotron.
As the cyclotron sped up immensely when firing, the vibration/twitch in the wand increased in an instant, first to vibration then to all out recoil as it actually fired. When firing ceased, the sensation decreased rapidly in the opposite order. (All out recoil to shudder/vibration back to the 4hz gyroscopic twitch at idle.)
I wonder if this gyroscopic twitch could be implemented somehow in a real prop build.
It would make the proton pack feel more cohesive and congruent I think. Actually probably not as you'd have to insert mini gyroscopes and what not into the wand. Probably wouldn't be worth the hassle for the tiny benefit in tactile realism it may provide.
And in any case who is to say what would be "realistic feedback" on a proton pack anyway? It's not like they exist.