Looking for 4-20mA Sensing Circuit

[spl]

Hello .,
  I need help, Does anyone have circuit or designed guide line about 4-20 mA circuit
I searching for current control circuit for sensor (maybe current regulator with self adjusting current).
For example if i use micro controller for sensing circuit , how can i control the total current consumption through the sensing unit (that mean Imcu+ Isensing=Isensor), when the mcu current is unpredictable.
   I have some circuit for temperature senser LM35 with LM317 current 4-20 mA for guide line but still not clear for me.
 Thank you very much for any suggestion,
 

Posted on: February 05, 2008, 02:05:04 02:05 - Automerged
Oh.. Sorry i post in the wrong section , this should be in the general electronic desing

[robban]

If You're using a PIC, have a look at Microchip site, maybe AN220 will do the work, otherwise You have a lot of application notes to choose between...

[inkwaterman]

Hi !

You can see the AD420 if you want to do a 4 wire trasmitter or the AD421 if you want to do a 2 wire trasmitter.

every IC is from analog devices.

There are also a good application note about this IC .

Good Job !

[lillbear]

Well i have found this...

yours

[kcid]

If you need sense 4-20mA of anyone device, " http://focus.ti.com/lit/ds/symlink/rcv420.pdf this IC is very useful.

[micropar]

Hi all,

I am looking for voltage(0-5v or +/-10v or similar) to 4-20mA converter.

Any help will be appreciated with thanks in advance,

Regards,
--micropar--

[fagari]

Here is good document for V to 4-20 mA convertor.

[spl]

Hello
   I found this circuit in transmitter datasheet,which close to my requirment
 Could anyone tell me or make some guide for design this circuit.

[fagari]

Hi Spl

This circuit is not 4-20 mA sensor.

This circuit Load cell to 4-20 mA convertor.

[spl]

Yes it use for loadcell , but my point is how to buid up the circuit like this IC using simple opamp.(low cost)
my linearity and resolution is not too high,Please give me the guide if someone have done .
Thank you verymuch

Posted on: February 21, 2008, 06:08:17 06:08 - Automerged
Yes ' i Already found it.
  Thank you again for every comment , here it is