In this article, we discuss about How to** Convert Voltage to Current** using Resistor with different examples like 0-10 VDC to 0-20 mA Conversion, 0-5 VDC to 0-20 mA Conversion.

## Convert Voltage to Current

It is extremely simple to measure 0-10Vdc signal with a device that will measure only Current inputs. If Current input module available will accept a 0-20mA signal, but may not accept a 0-10Vdc signal directly.

Basically, Ohms law is used to calculate a resistor value in order to convert the 0-10Vdc signal to a current.

## Example : 0-10 VDC to 0-20 mA Conversion

Ohms law states: **R = V/I** where **V** is the Voltage, **I** is the current and R is the resistance** **

**R **= 10V/0.020A = 500 Ohms

**0mA**

**0.02A = 20mA**

## Example : 0-5 VDC to 0-20 mA Conversion

Ohms law states: **R = V/I** where **V** is the Voltage, **I** is the current and R is the resistance** **

**R **= 5V/0.020A = 250 Ohms

**0mA**

I= V/R = 5/250 = **0.02A = 20mA**

**Note:-**

- To avoid damage you must ensure that the external current source has short-circuit protection in all conductor cases.
- The external resistor is a source of error because of its dependency on temperature and its inaccuracy.
- In order to obtain measuring results that are as precise as possible it is recommended to use resistors with tolerances that are as small as possible.

Credits : myplctechnology blog

## 1 comment

You didn’t consider the internal resistance of the input.