Current Sensor 1. Introduction.

RE: Current Sensor 1. Introduction.

COMPACT — Sun, 04 Dec 2016 05:44:08 GMT

This makes me potentially loopy.

RE: Current Sensor 1. Introduction.

D_Hersey — Tue, 02 Feb 2016 18:44:31 GMT

Ultra-sensitive current measuring has its applications in physics and astrophysics, but, lest we forget, also in biological research, in studying the nervous system particularly.

RE: Current Sensor 1. Introduction.

D_Hersey — Tue, 02 Feb 2016 18:41:07 GMT

Now I feel like a pedantry Olympian!

The very definition of current is in flux:

Ampere

The definition of the ampere is undergoing a major overhaul—the current definition, which is difficult to realise with high precision in practice, is being replaced by a definition that is more intuitive and that is easier to realise.

Current definition: The ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed 1 m apart in vacuum, would produce between these conductors a force equal to 2×10⁻⁷ newton per metre of length.

Proposed definition: The ampere, A, is the unit of electric current; its magnitude is set by fixing the numerical value of the elementary charge to be equal to exactly 1.60217X×10⁻¹⁹ when it is expressed in the unit A·s, which is equal to C.

Since the current definition contains a reference to force which has the dimensions MLT⁻² it follows that in SI the kilogram, metre and second, the base units representing these dimensions, must be defined before the ampere can be defined. Other consequences of this definition are that in SI the value of vacuum permeability (μ₀) is fixed at exactly 4π×10⁻⁷ H·m⁻¹.^[34] Since the speed of light in vacuum (c) is also fixed, it follows from the relationship

that the vacuum permittivity (ε₀) has a fixed value and from

that the impedance of free space (Z₀) likewise has a fixed value.^[35]

One consequence of the proposed changes to the definition of the ampere is that the definition will no longer be dependent on the definitions of the kilogram and the metre, but will still be dependent on the definition of the second. In addition the vacuum permeability, vacuum permittivity and impedance of free space, which, in the current definition have exact values will, in the future, be subject to experimental error.^[36]

from WIKI:

https://en.wikipedia.org/wiki/Proposed_redefinition_of_SI_base_units#Ampere

RE: Current Sensor 1. Introduction.

D_Hersey — Tue, 02 Feb 2016 02:53:03 GMT

If ya' need ultra-sensitivity, you can use a SQUID

An Ultra High Sensitive Current Sensor based on Superconducting Quantum Interference Device

Now, I feel like a pedant.

RE: Current Sensor 1. Introduction.

e14 Contributor — Sat, 30 Jan 2016 01:10:14 GMT

I'm trying to replicate no. 6 Rogowski coil made on a PCB with integrator and amplifier as a project.

But I'm stuck with getting a software that allows mt to 'wrap' traces on a pcb board that can be exported to gerber format.

Anyone tried this before or have any suggestions how i can accomplish it?

RE: Current Sensor 1. Introduction.

e14 Contributor — Wed, 11 Nov 2015 08:27:16 GMT

Nice, this article gives an overview of the different current sensor technologies.

RE: Current Sensor 1. Introduction.

jw0752 — Sat, 21 Feb 2015 18:03:53 GMT

Hi Peter,

I enjoyed your overview on current sensors. I am hoping that you are going to cover the subjects outlined here in more detail. Always something new to learn.

Thanks John