Current sensor for Revpi

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lujakob
Posts: 4
Joined: 23 Jul 2020, 13:54

Current sensor for Revpi

Post by lujakob »

Hello,

I need a current sensor which will measure a direct current in the range of 0 to 2 Ampere.
I have an analog input module for my Revolution Pi, which I would like to use to connect this sensor.
Does anyone have experience with a suitable sensor which can be connected to the analog module of the Revolution pi?

Many thanks for the help:)
Regards
Ludwig
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dirk
KUNBUS
Posts: 2174
Joined: 15 Dec 2016, 13:19

Re: Current sensor fpr Revpi

Post by dirk »

Hello Ludwig, I can remember using a so called Rogowski Coil. Have a look here at this product which is able to measuere up to 10A.
Also have a look at the Data Sheet of the AIO module.
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RR4711
Posts: 229
Joined: 22 Feb 2018, 13:28

Re: Current sensor fpr Revpi

Post by RR4711 »

dirk wrote: 24 Jul 2020, 10:26 Hello Ludwig, I can remember using a so called Rogowski Coil. Have a look here at this product which is able to measuere up to 10A.
Also have a look at the Data Sheet of the AIO module.
@dirk: He wants to measure DC. Those coils only work with AC AFAIK. There is hall sensors-based ones available for example from LEM company. They work quite well, but need seperate supply of 5V for operation (some others +/-15V).
Like this one: https://www.distrelec.de/de/stromwandle ... p/17696305
Depending on how many turns you feed through the core it gets more or less sensitive.

@ludwig: If you don't need galvanic isolation you may actually use a simple shunt resistor to measure the voltage drop across it. ("limits apply", common mode voltage etc, depends on your application, would need more information about it)
lujakob
Posts: 4
Joined: 23 Jul 2020, 13:54

Re: Current sensor fpr Revpi

Post by lujakob »

Hey Dirk and RR4711,

many thanks for your replies.
I already have the sensor that Dirk is recommending and had no success because of it is measuring just AC.

RR4711, your sensor looks quite good and I gonna have a deeper look on it.
I gonna tell you then if I ordered this one and if I had success with it.

Best regards
Ludwig
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dirk
KUNBUS
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Joined: 15 Dec 2016, 13:19

Re: Current sensor fpr Revpi

Post by dirk »

Hi Ludwig, thank you for your positive response and thank you RR4711 for your useful hints.
lujakob
Posts: 4
Joined: 23 Jul 2020, 13:54

Re: Current sensor for Revpi

Post by lujakob »

Hey,

I ordered now the LEM Current Transducer LTS-6 NP.
Already tried to implement it but so far, I was not successful.
I always receive a value about 2500.
But I am not confident with how I wired the sensor to the Revolution Pi.
Would you please have a look on the circuit diagram I attached to this reply?

I am very thankful for your help:).
Please ask me if I should provide more information on it.

Best regards
Ludwig
Attachments
Circuit Diagram
Circuit Diagram
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Output PiTest
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RR4711
Posts: 229
Joined: 22 Feb 2018, 13:28

Re: Current sensor for Revpi

Post by RR4711 »

2500 is fine. The Sensor has it's zero at half the supply voltage (=2,5V), to allow for measuring positive or negative current. If you wrap a wire 3 times though the hole in the center and send the 2Amps current through it, you should measure either 2500-625 or 2500+625 depending on the current direction.

Markus
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