PI Question

[lucifer]

Hi Carl,
in the second edition of ITMD you mention that the decay response at turn-off is purely resistive which I understand and that's what makes discrimination difficult if not impossible. You also mentioned that if response is sampled at turn-on, it contains also a reactive component. What's the physics behind that? How does it come that the reactive response is present at turn-on only?

[Carl-NC]

During the TX pulse the coil current is constantly changing (rising exponential) and this generates both reactive and resistive responses. You also get a reactive response during the turn-off transition, up to the point where the coil current dies out.

[lucifer]

Got it, thank you.