500 A DC current sensor

[alec82]

dc current sensor

dear friends
i need some paper or design idea , schematic for sensing 500 ampere dc current.
i'm going to use hall effect sensor to measure this dc current.
best regards

 

[FvM]

diy current sensor

Yes it's basically possible. They are different design principle available, with different accuracy (ordered from low to high precision):
1. open magnetic circuit hall sensor (like Allegro ACS754)
2. closed magnetic circuit hall sensor without compensation/magnetic feedback(e.g. LEM HTFS)
3. compensating DC current sensor(LEM, Honeywell, diverse).

Variant 2 and 3 require a magnetic core, variant 3 also a feedback winding and amplifier

 

[alec82]

dc current sensor circuit

dear fvm
thanks for your post . i used ugn3503 and amplifier and pic mcu .but i got some problem such as offset. can u guide me to overcome this problem?
thanks in advance

 

[FvM]

hall effect sensor 500 amps

Unfortunately, I'm not currently involved in DC current sensor design, I'm rather looking at their properties from a user perspective. But it's no easy business, I think. Also you're stuck to the available magnetic sensor elements. I don't know exactly, if Allegro 3503, a discontinued device, as far as I know, is present state of the art.

 

[smxx]

ugn3503 current sensor schematic

hi
I have read about principel of one type of HAL CT . it inject a current to ct to sense zero voltage in hal sensor.
In this case I1=NxI2

 

[alec82]

current sensor diy

dear smxx
this circuit working for ac current but for measuring dc current have problem and got offset after a few second . as u known ct used for ac current.
regards

 

[smxx]

acs754 allegro schematic

Dear alec82
No it working in both AC and DC.
I have one of them for 4000A in an Aluminium Factory

 

[FvM]

ugn3503 for ac current

The sensor is following the said "compensating DC current sensor" operation principle. All high precision current transducers are exclusvely using this method. But as I also said, it's no easy business. There are many possible design problems that can cause unwanted behaviour. The first point is a suitable design of the magnetic circuit.

The industrial sensors, I know (e.g. from LEM or Danfysik) have a high µr core, a good symmetry compensation winding and very thin hall sensors. Offset and drift are in a ppm oder of magnitude.

 

[alec82]

measure ac current using ugn3503

dear friends
anybody know about compensating DC current sensor and their circuit?
thanks in advance

 

[Canadian_Jim]

dc current sensor schematics]

Are you referring to a Hall Effect sensor?

 

[alec82]

design of dc current sensor

Are you referring to a Hall Effect sensor?

yes . is there another sensor type for this purpose ?

 

[FvM]

high dc current sensor circuit

I don't understand, what your particularly asking for. The principal circuit given by smxx is obviously correct. You may want to add a PID controller or some other more sophisticated feedback amplifier, but that doesn't change the principle. It's also described in the same way by manufacturers


If you are looking for a DC current sensor DIY design, that's a bit more complicated. A lot depends on available hall effect sensors and magnetic cores, as said before.

 

[srinu249]

where we use this DC curent sensor

 

[salil_desai]

how did you do it??..m goin to work on it the 1st time..i want to measure a load current(DC) of 500A using micro-controller..m gona use CS3505..and a torroidal core...thats it...thats all i know..i dont know anything about how much flux is induced in wat core and its relation to the voltage generated on Vout of 3505..somebody please guide me..

 

[FvM]

You post sounds like: "I have a motor and four wheels, how can I build a car." There are various details involved with making a DC current sensor, e.g. what are the core data, what's the air gap shape, do you have a compensation amplifier circuit, what's your specification for the sensor?

 

[salil_desai]

ok...this is the 1st time i'm goin to do current sensing..so i dont have much idea on wat i'v gotta do...all i want is tht a 0-500A current be accurately sensed by the hall IC and generate a proportionate o/p voltage which i'l be giving to an ADC (with or without amplification??) ...and then to a microcontroller 89c52 which will then display the current value on LCD...atleast tell me where i'm gona get enough information so that i design this perfectly