In a setting similar to Roadside Picnic, non-man-made objects termed 'emitters' produce a periodic 'zone effect' of induced current, similar in effect to an EMP. This zone effect falls off in intensity over distance, and has a variable maximum strength depending upon the properties of the emitter itself.
The exact mechanism of action is unimportant and does not necessarily need to be an EMP; the intended effect is randomly induced current. Depending upon intensity, the result of exposure to zone effect ranges from minor computer errors to death from induced current in the brain.
What I'm trying to figure out is a logical progression of EMP-like effects between those two extremes. To try to qualify it, I've broken the effects down into a series of levels to generally describe the effects at varying levels of intensity.
As a rule of thumb, I'm broadly characterizing electronics technology as 'simple' (vacuum tubes, basic circuits), 'complex' (transistorized, simple PCBs), and 'advanced' (microprocessor-driven). This is a gross simplification to characterize varying resistance to EMP-like effects.
The progression I have at the moment goes like this:
Level 1: Advanced electronics experience abnormal behavior. Bob's phone is restarting randomly.
Level 2: Advanced electronics temporarily stop functioning. Complex electronics experience abnormal behavior. Bob's phone won't turn back on, and now his radio is emitting random static, and the signal keeps fading in and out.
Level 3: Advanced electronics permanently burn out. Complex electronics temporarily stop working. Simple electronics experience abnormal behavior. Bob's radio has cut out entirely, and his flashlight is flickering.
Level 4: Complex electronics permanently burn out. Simple electronics temporarily stop working. The flashlight gives out. Nothing with a circuit is working.
Level 5: All electronics permanently burn out. The human brain starts to experience interference, manifesting as hallucinations and dementia. Bob sees things in the corner of his eye that aren't there when he turns to look. His cognition is slow, and his head hurts.
Level 6: Rapid incapacitation followed shortly by death. Bob falls unconscious and is dead within minutes.
Does this represent a plausible progression of effects due to increasing intensity of an EMP-like phenomenon? If not, how can it be altered to be more consistent with the effects of induced current in the real world?