from the Automation List department...
0-5volt to 4-20ma converter
Application Questions and Problems topic
Posted by Mesquita on 23 October, 2005 - 8:50 pm
I need to convert a signal from 0-5 volt to 4-20ma. How can I do this?

Posted by sankar on 24 October, 2005 - 10:37 pm
if you have siemens plc system u select input module 0-5 volt analog voltage i.put selection and get the calculated value in words to get exit from 4-20 mA analog out module.

other vise you need real convertor of V - mA.check in internet lot of different sourse are available to buy...
thank you sir...

i am sankaranarayanan..

Posted by Bob Hogg on 24 October, 2005 - 10:48 pm
If the device needs power then this will do the job converting a resitsnce to 4-20. It will power up a resistance device and produce a 4-20 out.
and you have 4-20.

Bob Hogg

Posted by EVANDRO VIZICATO on 24 October, 2005 - 11:05 pm
You can use a converter from Phoenix Contact. Visit the website

Evandro Vizicato

Posted by Ing. Molina on 24 October, 2005 - 11:35 pm
You are kidding right? i mean, use a resistance for god sake, how do you convert voltage to current? that's electronics basic.

good luck.

Posted by Kirk C on 26 October, 2005 - 10:17 pm
Well, a resistor will work when going from 4-20 ma to 1-5 volts. But it won't necessarily work going the other way. Current loop transmitters are designed to drive a load that can vary from application to application, from 50 ohms to 750 ohms, typically. A current transmitter is able to compensate for the addition or deletion of a loop instrument by using more or less power to drive the loop. A fixed-size resistor could not do this and voltage sources are not designed to power current loops. Voltage sources expect a high impedance measurement device to be attached.

Posted by Anonymous on 24 October, 2005 - 11:59 pm
A 250 ohm series resistor should do the trick.

Posted by David Adams on 28 October, 2005 - 1:01 am
That will give them 0-20 ma not 4-20ma. Look at converters from someone like Weidmuller or Phoenix Contact.

Posted by Anonymous on 25 October, 2005 - 12:11 am
Contact Pepperl+Fuchs..Model KFDx-DCV. Dip switch selectable voltage input and dip switch selectable output. tion.pdf

Posted by Anonymous on 25 October, 2005 - 12:19 am
Phoenix Contact has a transceiver for this purpose, contact your local dealer.

Posted by Lee Thanh Ha on 22 November, 2005 - 11:13 pm
Please send us your e-mail. I will forward an e-mail with circuit voltage to 4..20mA.

Posted by on 23 April, 2008 - 12:22 am
Let using IC: AD693, AD694 or using this simple cir:

Good luck! ^_^

Posted by reza on 1 June, 2008 - 3:49 pm
u can use of adc and then dac for changing your span from 0-5 to 4-20 and use mcu.

Posted by zaki on 3 June, 2008 - 12:04 am

If you can't make it in basic way like using resistors, you can provide signal conditioners on the market with several input signals as your (4-20mA) output signal. Like we've done on my previous project with several analog signals to convert.

We have been using these, try this:

Posted by Candy Yu on 12 January, 2009 - 3:40 am
You only can use a converter module, such as :ISO-U2-P1-O1. That price is very good, easy to use.

About the datasheet, check the link:

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