current sensor

Dear all.

I am trying to build simple current sensor circuit. I wanted to measure current of device rated @ 24v , If current exceed 1A need to trip relay.

let me know is there any current sensor IC is available which gives analog 0~5v output . measure current range 1A.

If i am using resistor network.I.e Dc shunt based How can measure current in arduino Analog port. If anyone can share simple circuit diagram it will be more helpfull.

http://openenergymonitor.org/emon/buildingblocks/dc-shunt
Here i found link. But how to choose value of
IM,RB,RA,Rsense
if i wanted to measure 24v,1A current

The ACS series current sensor use a hall sensor to measure the current.
With the ACS series, the 24V is not connected to the 5V circuit of the Arduino, but... the sensor are sensitive for magnetic fields from transformers and motors.
Here is one with extra adjustable gain: SparkFun Current Sensor Breakout - ACS723 (Low Current) - SEN-14544 - SparkFun Electronics

Recently the current sensing has moved to special chips that are made for high-side current sensing.

Why do you want an output of 0...5V for 0...1A ? You can solve that in the sketch if it doesn't have that output voltage. It might even be better when you use the internal reference of 1.1V (to remove inaccuracy by the 5V of the Arduino) and have 0...1V for 0...1A.

yes, seems the ACS712 module is right for your application

Yes i know. Since i wanted build my own. I am not getting seller in INDIA. But in element 14 price itself 300RS and where module comes around 400RS

Please let me know where i can get it. If any Indian supplier this IC available let me know.

https://www.mgsuperlabs.co.in/estore/ACS715-Current-Sensor-Carrier-0-to-30A
http://hacktronics.co.in/home/248-acs712-5a-range-current-sensor-module.html

The WCS2720 seems to be cheaper, but I don't know that module at all.
http://hacktronics.co.in/home/722-wcs2720-hall-effect-base-linear-current-sensor.html

Thanks for link. I have already explored these links.
Since i am doing my own I am looking for only ICS.

where price is 330Rs. since i have 6 IO s . i wanted to integrated on single board.I am looking for vendor Who supply iC. These IC seems expensive for my application.
Locally i checked i didnt get any supplier.

AMPS-N:
Thanks for link. I have already explored these links.

Okay, sorry. I didn't understand 'element 14', but that is a supplyer. It seems to be connected to farnell.

This list shows that it is all about the quantity.
The 5A version is 1.80 dollars for 3000, but 4.82 dollars for just 1.