power measurement

[noobita]

hello guyz! we are trying to measure a room's power consumption and we plan to use allegro current sensors.. can it measure properly currents from  100mA to maximum of 15 A?   

[Dave]

Depends on what your definition of properly is.

[station240]

You need to look at the datasheets, see what sort of accuracy/error range it has. One current sensor I looked at is 1% accuracy, at 100A that means it's limited to 1A steps.

For your example, I think 20A is the nearest size for Current Sensors anyway, so 200mA. See what you can find that is 0.5% or better (lower) accuracy.

[dom0]

One current sensor I looked at is 1% accuracy, at 100A that means it's limited to 1A steps.

±1 % accuracy of full scale means that with 100 amps through the sensor it can read anywhere between 99 A and 101 A. Doesn't mean that the resolution is 1 % (~2/log(2) ~7 bits).


Accuracy is an interesting spec for mass production. For homebrew use one is normally more interested in drift (tempco, long-term) and linearity, because you can calibrate things easily manually to zero out errors.

[noobita]

TRIAD MAGNETICS    CSE187L  Current Sensing Transformer, someone suggested this one.. will it help me solve my problem? http://www.mouser.ph/ProductDetail/Triad-Magnetics/CSE186L/?qs=sGAEpiMZZMvHq2mgYB5gN1Bs7N%252bzhopi4eI8yg65QUA9r%252bby8sg4Zw%3d%3d

[noobita]

i'm not good at looking at/understanding Datasheets. i can replace those acs758s with current transformers right? all i want is to measure current from 100mA to 10A..