current Measurement

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Anonymous
Not applicable

Hello everyone,

   

how can the current measurement be done with PSOC 5? Under paragaph 8.12.2 First Order Modulator-SC Mode, there is written, that applications such as current measurement can be done.

   

In the case, which it is possible, what is the theoretical sensitivity? I would like to measure current arround 20A (the voltage is 800mV)

   

Thanks for your help

   

Regards

   

Rosine

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4 Replies
ETRO_SSN583
Level 9
Level 9
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Questions -

   

 

   

1) Hi or low side measurement ?

   

2) The 800 mV comes from what, is it directly proportional to current

   

in device ?

   

3) Accuracy and resolution of measurement needed.

   

4) DC or AC measurement ?

   

5) What doc is this in "Under paragaph 8.12.2 First Order Modulator-SC Mode,"

   

 

   

Regards, Dana.

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odissey1
Level 9
Level 9
First comment on KBA 1000 replies posted 750 replies posted

@Rosine,

   

First, you need some transducer Current -> Voltage, like this one

   

http://www.ebay.com/itm/New-design-20A-range-Current-Sensor-Module-ACS712-Module-Arduino-module-ACS7...

   

 

   

Second you will need to measure Transducer's Voltage outout using PSoC5LP DelSigADC (see PSoC examples).

   

odissey1

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Anonymous
Not applicable

Hello Dana, odissey1,

   

1) Hi or low side measurement ?

   

what is Hi or low side measurement, please can you be more precise?

   

 

   

2) The 800 mV comes from what, is it directly proportional to current in device ?

   

The 800 mV is the voltage output of the current sensor. I think that  PSoC5LP DelSigADC can measure this voltage level as suggested by odissey1.

   

 

   

3) Accuracy and resolution of measurement needed.

   

I don´t understand very well

   

4) DC or AC measurement ?

   

The HLSR-P serie current sensor deliver a DC Voltage

   

5) What doc is this in "Under paragaph 8.12.2 First Order Modulator-SC Mode,"

   

It is CY8C58LP_001-84932_OG_V

   

 Thanks for replying and the suggestions

   

Regards

   

Rosine

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ETRO_SSN583
Level 9
Level 9
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What is Hi or low side measurement, please can you be more precise?

   


   

Hi side measurement means you place the current sense R in the hot side of

   

the power to the part, in this case PSOC Vdd. Low side would be in the Vss

   

lead of PSOC.

   

 

   

 

   

3) Accuracy and resolution of measurement needed.

   

 

   

Accuracy is how close to the actual value do you want to read the current. So if

   

current is 1 A do you wish to measure 1A +/- 10% or +/- 5% or.....

   

Resolution is when you digitize a value each bit of A/D represents the minimum

   

detectable current value. So say you use A/D at 10 bits, its full scale range is

   

1.024 V, then its resolution is 1.024 V / 1024 = ~ 1 mV

   

 

   

5) What doc is this in "Under paragaph 8.12.2 First Order Modulator-SC Mode,"

   

It is CY8C58LP_001-84932_OG_V

   

 

   

 

   

I am still not clear on what document you are lookimng at, datasheet for part, ap note,

   

TRM......

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