Pulse completeness from the L over R time constant
Established physics
When resistance and inductance are known, the report shows how completely each pulse builds up current, using the coil's electrical time constant.
Where it appears in the report: Engineering Details, Design and Engineering Guidance
The evidence
In a resistor-inductor circuit, the current rises toward its full value on a time constant equal to inductance divided by resistance. It reaches about 95 percent of the build-up at three time constants and about 99 percent at five. The report checks each pulse width against these standard points to judge whether the pulse is sufficient, marginal, or cut short.
Coil current does not switch on instantly; it builds up along this curve, set by the coil's L/R time constant. It reaches about 63% of full after one time constant, 95% after three, and 99% after five. If the pulse is at least about three time constants long, the current has essentially finished building, so the pulse is complete.
Primary sources
Standard resistor-inductor (RL) circuit result; any introductory electromagnetics or circuits text.
