0-10V to 4-20mA Converter Schematic
Introduction
In industrial control systems, 4-20mA current loops are widely used for transmitting analog signals over long distances. However, many sensors and transmitters output a 0-10V signal, which needs to be converted to 4-20mA for compatibility with the control system. In this article, we will discuss the design of a 0-10V to 4-20mA converter schematic.
Theory of Operation
The 0-10V to 4-20mA converter circuit works by using an operational amplifier (op-amp) to amplify the input voltage and then convert it to a current signal. The output current is proportional to the input voltage, with 0V input resulting in 4mA output and 10V input resulting in 20mA output.
Schematic Diagram
Here is a simple 0-10V to 4-20mA converter schematic diagram:
+-----------+
| |
| R1 R2 |
| 1k 2k |
| |
+-----------+
| |
| |
v v
+-----------+
| |
| OP07 |
| (Op-Amp) |
| |
+-----------+
| |
| |
v v
+-----------+
| |
| R3 R4 |
| 1k 1k |
| |
+-----------+
| |
| |
v v
+-----------+
| |
| Q1 R5 |
| (NPN) 1k |
| |
+-----------+
|
|
v
+-----------+
| |
| Vin Iout |
| 0-10V 4-20mA |
| |
+-----------+
Component List
- R1, R2, R3, R4, R5: 1kΩ resistors
- OP07: Operational amplifier (op-amp)
- Q1: NPN transistor (e.g., 2N3904)
- Vin: 0-10V input signal
- Iout: 4-20mA output current
How it Works
The circuit works as follows:
- The input voltage Vin is applied to the non-inverting input of the op-amp (OP07).
- The op-amp amplifies the input voltage and outputs a voltage signal proportional to the input voltage.
- The output voltage from the op-amp is applied to the base of the NPN transistor (Q1) through a resistor divider network (R3 and R4).
- The transistor amplifies the output voltage and converts it to a current signal.
- The output current Iout is proportional to the input voltage Vin, with 0V input resulting in 4mA output and 10V input resulting in 20mA output.
Advantages
The 0-10V to 4-20mA converter circuit has several advantages, including:
- High accuracy: The circuit provides a high degree of accuracy, with a linear transfer function between the input voltage and output current.
- Low power consumption: The circuit consumes low power, making it suitable for battery-powered applications.
- Simple design: The circuit is simple to design and build, requiring only a few components.
Conclusion
In this article, we have discussed the design of a 0-10V to 4-20mA converter schematic. The circuit is simple to build and provides a high degree of accuracy, making it suitable for a wide range of industrial control applications.
