current sensor ACS712

how to calculate the current value using ACS712 20Amp current sensor

Manoj Ramamoorthy said:

how to calculate the current value using ACS712 20Amp current sensor

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refer Datasheet of current sensor & connect burden accordingly then see result. For more details mention ur application

just connect the V1out pin to your controller's ADC pins and configure uC to read the analog value. Now you 'll get a hex value in your ADC result register...
Calculate the known values hex values, from known values find unknown values by code...

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Manoj Ramamoorthy said:

how to calculate the current value using ACS712 20Amp current sensor

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If you need further details post the controller you are using and the application needed in detail...

my application is to measure the current flowing to the 230V 50Hz 60 wats motor.
i refereed the data sheet and i found that the output of the current sensor and multimeter is different.

i am using atmega32

Manoj Ramamoorthy said:

my application is to measure the current flowing to the 230V 50Hz 60 wats motor.
i refereed the data sheet and i found that the output of the current sensor and multimeter is different.

i am using atmega32

Click to expand...

How do you measure the O/P of the sensor? Do you have ADC code? If you have post that too...

i measured the output through multimeter.

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the output of the sensor is 2.89V and the actual motor current measured by using multimeter is .15A

hello,

i am interrsting by this subject, but not yet started to work on it...

measure-offset:
2,89-2,50= 0,390V
sensivity : 100mV/A so gives 3,9A (maybe true for DC current) ?
instead of 0,15A AC efficace value ?

did you check ACS712 output with a scope ?


it seems the rule is not the same for AC current as DC current.
see datasheet page 12
Application 4. Rectified Output. 3.3 V scaling and rectification application
for A-to-D converters. Replaces current transformer solutions with simpler
ACS circuit. C1 is a function of the load resistance and filtering desired.
R1 can be omitted if the full range is desired

use of a perfect rectifier with an AOP could be the good solution to get "DC efficace value" to the ADC input.

please confirm :
what is you power supply voltage for the ACS712 ?
what is the output measurment at 0 amps ?
shape of output ACS712?