YHDC current sensor - the theory please

[flotulopex]

Sorry guys for not reponding earlier - I'm still waiting for 20A:50mA current sensor to arrive; my 100A:50mA are far too low and "out of range" for what I intend to measure.

BUT I could grab a 5A:1V one from a friend today so I'm back on my workbench.

To have "better" values -measures with FLUKE 177- , I now use my 230VAC hairdryer:
Pos 1: fan only = YHDC:54mVAC - FLUKE: 1.1A
Pos 2: fan + low heating = YHDC: 170mVAC - FLUKE: 3.5A
Pos 3: fan + high heating = YHDC: 320mVAC - FLUKE: 6.6A


Since I now use a voltage output type sensor, I leave the burden resistor out, right?




And here are my readings:

OFF:



Pos 1:



Pos 2:



Pos 3:



I can't still figure out what I'm reading.

[richard]

you cannot use a current transformer that way without a burden resistor.
by voltage sensor do you mean ACS712 or similar ?
if so that circuit is incorrect, typical use