How to say or what is the name of this voltage?

Thread Starter

Sweetman Kim

Joined Jun 15, 2021
I would like to ask the name of voltage in the middle of power line.

In automotive, long and long power harness exist and the those are also the source of noise and transient voltages.

Below circuit is simulate the voltage engaged in the middle area of power line from transient source to voltage clamping devices for protect.


TVS1 is 30V type.

When I applied 200V thru 2 Ohm current limiter,


TVS1 clamping well as 38.5V, but the voltage at D1 position ( No function in circuit, only for check the voltage in that point, no avalanche, no breakdown ) is 56V.

Of course, 2m wire working like inductor and require time to charging and the voltage will be down after several micro seconds.

My question is what is the name of the voltage in that D1 point?

Floating voltage looks not match, mmmmmm...

Please, comment.

Thanks all.


Joined Nov 6, 2012
I hope that I understand your question .............

When a Voltage, or Current, or both, have radical changes from what is "normal",
and this happens during a "switch-on", or, a "switch-off", event,
this is usually called "Over-Shoot", or, "Ringing", or, just plain "Oscillation", or, unwanted Electrical "Noise".

For this reason, I have around ~10 different Capacitors in my Truck for noise suppression,
and all Electronic Devices have a dedicated Wire to the Battery.

The worst problems in a Car are usually from Wires that are too small, or,
using the Sheet-Metal-Body of the Car as a Ground-Return to the Battery.
This is why I have installed 6 separate 10-gauge Grounding-Wires in my Truck,
( plus 2- 6-gauge Grounds ),
they all go to "Ground-Distribution-Blocks" in important areas,
and the Truck Body and Frame are not used for any Electrical connections.