1.
SILIGURI INSTITUTE OF TECHNOLOGY
DEPARTMENT OF ELECTRICAL ENGINEERING
Presented by
Name
Roll :
Department :
Semester : 6th SEMESTER
Presentation on : Digital Controller
Course Name: Digital Control System Course Code :PE–EE-601A
PRIYASHREE NANDI
11901621030
ELECTRICAL ENGINEERING

2.
Topics
Introduction
What is a Digital Controller?
Where is Digital Controller used?
How does Digital Controller work?
Disadvantages of Digital Controller
Conclusion
Advantages of Digital Controller
Example of Digital Controller
References

3.
Introduction
A central digital central digital controller receives a signal from a phase/magnitude discriminator that measures
the input impedance to the tuning/matching box, and sends that information to the central digital controller,
which in turn provides control signals to the tuning/matching box to keep the input impedance of the box at 50 Ω
and zero phase angles a signal from a phase/magnitude discriminator that measures the input impedance to the
tuning/matching box, and sends that
A central digital controller receives a signal from a phase/magnitude discriminator that measures the input
impedance to the tuning/matching box, and sends that information to the central digital controller, which in
turn provides control signals to the tuning/matching box to keep the input impedance of the box at 50 Ω and
zero phase angle.
Control panels are essential elements of any electrical device. Control
panels are especially important on HVAC devices and heater elements.
They enable you to control the temperature, voltage, and pressure more
easily for a smoother operation of the device.

4.
What is a Digital Controller?
A digital controller is a small digital unit that acts as a system controller. Depending on the controlling
requirement, a digital controller can take the form of a desktop computer or it can be as small as a micro
controller. The Laplace transform is replaced by Z-transform in the digital controller wherein a discrete time
signal in the form of a sequence of complex or real numbers is converted into a complex frequency domain
representation.

5.
Where is digital controller used?
A digital controller is a system used for controlling closed-loop feedback systems . The controller
implements algebraic algorithms such as filters and compensatory to regulate, correct, or change the
behavior of the controlled system.
Digital controllers are mostly used as a feedback system.

6.
❑ COMPONENTS OF DIGITAL CONTROLLER:
A typical digital controller has the following components:
· A/D Conversion – Analog inputs are converted into a digital format.
· D/A Conversion – Digital outputs are converted into analog inputs for the device.
· A program relating the outputs and inputs.
How does a digital controller work?
It measured the actual state of the device and compares it with the target state.
The control system ,then , takes the appropriate action to stop or allow the heating process . When the
temperature gets lower than the specified value ,the digital controller activates the heating system.

7.
➢ It gives better resolution . Advantages of Digital Controller
➢ Coding of digital signal and digital communication: The entry of digital control to the industrial
scenario was chiefly through the big process industries like steel mills, chemical, fertilizer and
cement industries because of the cost advantage.
➢ Time sharing: One communication channel may be used to transmit discrete control signal for
more than one control systems.
➢ Control system with inherent sampling: Sampling is inherent in some applications, and it is
necessary in other applications, it is desirable for still other applications.
➢ Digital computer implementation of sophisticated control law: Dedicated minicomputers and
microprocessors can be used to implement sophisticated algorithms such as high-performance state
variable manipulation, Kalman Filtering and Adaptive control.
Advantages of Digital Controller :

8.
➢ System design: The mathematical analysis of a digital controller is sometimes more complex and
more tedious as compared to continuous data control systems . Disadvantages of Digital Controller
➢ System stability: System stability is degraded by converting a continuous data system to digital
system. Even a stable second order system can be unstable when converted to discrete version.
➢ Loss of signal information: The signal output from the digital controller is to be converted to analog
form before applying to the actuators. However, the reconstruction of digital to analog signal using
hold circuits is only an approximation of the actual signal. So, some signal information is lost in the
process.
➢ Controller dynamic update: Analog to Digital (A/D) and Digital to Analog (D/A) converters along
with digital computer introduce some time delay.
➢ Software errors: The complexity of the controller is in the software implemented algorithms, which
may contain errors
Disadvantages of Digital Controller :

9.
Digital controllers in an industrial heating solution enable you to control the heat and temperature of the device
conveniently. Heat transfer is efficiently and stably maintained so that overheating issues can be prevented. Not
only do digital controllers regulate heat, they put safety mechanisms in place. A sensor device is installed in the
process heater. It measures the actual state of the device and compares it with the target state. The control
system, then, takes the appropriate action to stop or allow the heating process. When the temperature gets lower
than the specified value, the digital controller activates the heating system. When the temperature reaches the
threshold level, the heating process is automatically stopped. The controller has a digital display which
provides a clear view of the state of the device. The sensor, installed inside the heater, monitors the temperature
of the device while the digital display shows the information in Celsius or Fahrenheit values.
❑ Digital Controllers in Heaters :
Example of Digital Controller :

10.
Conclusion
Digital controllers have become popular in recent times as they are inexpensive. A small micro controller can
be purchased for only $5. Digital controllers offer the flexibility to configure them easily using software. You
can change the parameters and scale the performance of the device. In addition, digital controllers are less
susceptible to environmental impact when compared with analog controllers.

11.
References
❖ https://www.sciencedirect.com/topics/computer-science/digital-controller
❖ https://www.wattco.com/casestudy/what-is-a-digital-controller/
❖ https://www.google.com/imgres?imgurl=https%3A%2F%2Fwww.wattco.com%2Fwp-
content%2Fuploads%2F2017%2F04%2Fimage_upload_25.jpg&imgrefurl=https%3A%2F%2Fwww.wattco.com%2Fca
sestudy%2Fadvantages-and-limitations-of-digital-control-panels-for-
industries%2F&tbnid=6WjvAa5HYJvJtM&vet=1&docid=ujzZCOTNOla8rM&w=1341&h=1562&hl=en-
US&source=sh%2Fx%2Fim
❖ https://images.app.goo.gl/AYBcQR9xyq4p7tNa8