Today is...
Friday, February 24, 2017
Welcome to, the global online
community of automation professionals.
Featured Video...
Featured Video
EtherCAT with CTC’s master lets your multivendor network play well together...
Our Advertisers
Help keep our servers running...
Patronize our advertisers!
Visit our Post Archive
0-5volt to 4-20ma converter
How can I converte a 0-5 volt signal into 4-20 ma?

I need to convert a signal from 0-5 volt to 4-20ma. How can I do this?

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..

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

By EVANDRO VIZICATO on 24 October, 2005 - 11:05 pm

You can use a converter from Phoenix Contact. Visit the website

Evandro Vizicato

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.

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.

A 250 ohm series resistor should do the trick.

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.

Contact Pepperl+Fuchs..Model KFDx-DCV. Dip switch selectable voltage input and dip switch selectable output.

Phoenix Contact has a transceiver for this purpose, contact your local dealer.

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.

By on 23 April, 2008 - 12:22 am

Let using IC: AD693, AD694 or using this simple cir:

Good luck! ^_^

u can use of adc and then dac for changing your span from 0-5 to 4-20 and use mcu.


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:

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: