Machanisms

Machanisms

What is a Firewall?

Introduction | What is a Firewall ?

In these days, It is crucial to protect business and personal data and age of continuously changing cyber threats. One of the simplest ways to provide cybersecurity is using a firewall, which filters traffic to prevent unauthorized users from entering a network while allowing legal users to do so. In this situation, firewalls are always required for companies, as well as individual user protection and mobile device security.

How Firewall Works

Firewall works on the principle of filtering the networks’ data, flows according to a set of parameters corresponding to their security protocols. Packets that are unfavorable in the system are blocked from reaching your system while authorized packets pass through.

How Firewall Works?

Basic Firewall Functions:

  • Traffic filtering: According to IP address, protocol, or port number.
  • Logging and monitoring: Firewalls monitor traffic patterns and provide notification of such activities that are considered abnormal.
  • VPN integration: Some firewalls are usually capable of working with Virtual Private Networks (VPN) for protected communication over a network that is open.

Importance of Firewall

1. Network Security

Firewalls act as a protective layer between internal networks and external threats from the internet. They monitor the traffic both in coming and going out according to the security protocols set to block the traffic that is malicious to the systems and protect the system from cyber-attacks.

2. Data Protection

Firewalls are used by businesses to prevent unauthorized users from accessing data. Besides locking the unauthorized individuals out of the system, firewalls also guarantee that the data is not transmitted or shared through insecure connection.

3. Regulation and Compliance

In many industries, firewalls are among the necessary security features for compliance with such standards as GDPR, HIPAA, and PCI DSS. Business owners require additional layers of security that are essential in meeting the legal requirements and safeguarding customers’ information.

Types of Firewalls

  1. Packet-Filtering Firewalls: Examines every single data packet and prevents packets that do not conform to pre-defined security standards.
  2. Stateful Inspection Firewalls: Regulates the number of active connections and take decisions correspond to the context of the traffic.
  3. Proxy Firewalls: Interacts with the users and external network by filtering requests and results.
  4. Next-Generation Firewalls (NGFW): These may comprise IDS, IPS, and application filtering mechanisms.

Types of Firewall

Advantages:

  • Improved Security: The firewalls are used as the first barriers to cyber threats filtering out malicious traffic from the system.
  • Prevent Unauthorized Access: Any access to the network is restricted, users as well as devices that are allowed to connect to the network.
  • Customizable Protection: Use of firewalls can be scaled to meet the level of security required in a certain network or for a certain user.
  • Centralized Management: Handling all network traffic at a central point is perhaps the most significant feature of hardware firewalls for businesses.

Disadvantages:

  • Complex Configuration: This means that to gain the maximum level of protection, firewalls need to be properly configured, and this can be a difficult thing especially for novices.
  • Cost: Soon, advanced firewall solutions including the Plug-n-Play hardware types will be expensive for small businesses or the average user.
  • Performance Impact: Firewalls may introduce latency in a network and more so if they have not been configured properly or if they are overloaded.
  • Limited Protection Against Insider Threats: Firewalls are mainly used to prevent connections from the outside world, while they do not have the strength to prevent inside attacks.

How to Disable Firewall? | Firewall CMD Disable:

In some situations, it will be required to turn a firewall off at least for a while. Here’s how you can disable a firewall using the command line.

Windows CMD to Disable Firewall:

Go to Command Prompt (CMD) and right-click on it and select “Run as Administrator”.

Now, run the following command:

What is Firewall

This will disable the Windows Firewall for all the network settings profiles which are Domain, Private, and Public.

CentOS 7 Firewall Disable:

Access our server through an SSH.

Now, run the following command to stop the firewall service:

What is Firewall

Permanently Disable Firewall:

To disable the firewall permanently (so it does not start at boot), run the following command:

What is Firewall

 

Firewall For Android

While most Android gadgets are pre-installed with security ware, there are still other users who desire to download specific firewall applications.

3 Best Firewall Apps for Androids

  1. No Root Firewall: This app doesn’t have to be rooted, and its central function is to filter Internet access for applications.
  2. Net Guard: An open-source tool that acts as a firewall differently in that it seeks to tightly control how any of your applications are allowed to make connections over the internet.
  3. AFWall+: If you are an Android user with rooted device, then enjoy all the features that this firewall app provides for controlling and filtering both the outgoing and incoming traffic.

5 Best Windows Firewall Solutions

Windows operating systems come with a built-in firewall. Substantial additions can be provided by a third-party firewall. Here are some of the best firewall solutions for Windows;

  1. Windows Defender Firewall: They are the built-in Windows Defender that has to offer good protection without putting a considerable load on the system.
  2. Zone Alarm Free Firewall: It is one of the free firewall tools that comes with additional features such as stealth mode and the interface is easy to understand.
  3. Comodo Firewall: Offer superior security for both incoming and outgoing connections, with extra settings for the more experienced users.
  4. Glass Wire: A firewall which is visual-based and that will scan your network and give you information on which application(s) is/are utilizing your bandwidth.
  5. Norton Smart Firewall: Pre-installed in Norton Security Suite, it uses advanced web suspicion protection plus protection compared to Web Browsers.

Does Firewall Slow Down the Internet or PC?

Yes, firewall may slow down your PC or internet connection Sure, depending on the sort of firewall, how it’s configured, and how well the system performs overall. Here’s how:

Firewall Slow Down the Internet or PC

1. Firewall Impact on Internet Speed

  • Packet Filtering and Inspection: Firewalls inspect the traffic flows within the networks with the purpose of filtering the data packets. The stateful inspection or Next-Generation Firewalls (NGFW) may consume considerable amount of resources because of DPI. This slows down the web connection in case the firewall is taking ample time to analyze each packet.
  • Bandwidth Throttling: Some of the firewalls have options in which they can specify particular applications or services, which in turn affects the Internet speed.
  • Cloud-Based Firewalls: Some organizations employ use of cloud based firewalls where data will pass through the firewall before reaching to its destination. This extra step can result in latency and slow speed.

2. Firewall Impact on PC Performance

  • CPU and RAM Usage: An application that sits in the background and identifies the incoming and outgoing traffic consumes CPU and RAM especially when parsing the traffic or running through complex filters. This is especially true where the computer has few resources to work with and may cause PC sluggishness.
  • (IDS) and (IPS): These firewalls come with in-built IDS/IPS that can scan and identify threat in real time. This is done by the use of processing power, that may result in slow down the PC if resources are limited.

Can a Slow PC or Internet Affect Firewall Performance?

Yes, It is true due to some reasons.

Reason 1: If your PC is already slow due to insufficient hardware or malware, then adding a firewall can result in further slow down the system.

Reason 2: If you have a slow internet connection, then add firewall may further slows down the performance by adding latency or processing delays.

Factors That Affect Firewall Performance:

  • Configuration: Misconfigured firewalls are very likely to work with unrequired data and hence slow down the speed. e.g; Checks on internal trusted traffic may reduces the performance.
  • Hardware Firewalls: Generally, These firewalls don’t hinder the performance of certain PCs since they handle the traffic on perimeters.
  • System Resources: The current generation computers with fairly good processing power and memory will not be slowed down by a well optimized firewall.
Machanisms

Variable Speed Electric Motors

Introduction:

Variable speed electric motors are some of the most needed and common electric motors used in industries today. These motors are anticipated to run at speeds, to enable their control and optimal efficiency in terms of energy usage. The objective of this article is to discuss the working principle, components, types of winding, and modes of operation of variable speed electric motors.

Working Principle:

Variable speed electric motors utilize electromagnetic induction as their mode of operation. In this case, when an electrical current is passed through the motor’s windings, it produces a magnetic field, hence rotating the rotor. Therefore, for different applications, the speed of the motor can be controlled according to the required frequency and voltage of the electrical input.

Variable Speed Electric Motors
A VFD simply controls the frequency of the electrical supply

 

Namely, the variable speed control of an electric motor is primarily a matter of controlling the frequency and voltage which is supplied to the motor. This is normally done with the help of Variable Frequency Drive better known as VFD in short.

A VFD simply controls the frequency of the electrical supply, hence giving control of the speed of the motor. For an AC motor, the speed is determined by the formula:For an AC motor, the speed is determined by the formula:

Speed (RPM) = 120 × Frequency (Hz) / No.s of Poles

In this manner, with the help of varying the frequency the VFD is able to step up or step down the motor speed while not influencing the voltage as much thereby leading to a more efficient and stable performance. One of the advantages of this system is that it can achieve a high acceleration and low deceleration which in many cases is desirable when using the system.

Parts and Functions:

As mentioned above, variable speed electric motors are made up of the stator a stationary part of the motor including:

Parts

Functions

Stator:

Rotor:

Variable Frequency Drive (VFD):

Bearings:

Shaft:

Cooling System:

Feedback Sensors:

Control Panel:

Windings:

Housing/Enclosure:

Generates the magnetic field to drive the rotor.

Interacts with the magnetic field to create motion and torque.

Adjusts the motor’s speed by controlling frequency and voltage.

Supports the rotor and reduces friction.

Transmits rotational motion and torque to connected equipment.

Removes excess heat to prevent overheating.

Monitors speed, position, and performance for precise control.

Allows operators to manage speed and operational settings.

Creates the magnetic field inside the stator.

Protects internal components and aids in heat dissipation.

How to Increase Speed:

The following are some of the ways through which one can be able to raise the speed of a variable speed electric motor. One of the most often used techniques is to alter the rate of the electrical input signal controlling the speed of the motor. The second way is in modifying the number of poles in the winding of the motor and its possible effect on the speed characteristics. Moreover, there are more advanced ways of controlling the speed of the motor through employing of specialty control systems and software given below:

  • Adjust Frequency via VFD: Increase the frequency supplied to the motor using a Variable Frequency Drive.
  • Increase Voltage: Raise the voltage within the motor’s rated limits.
  • Reduce Mechanical Load: Decrease the resistance or load on the motor.
  • Use Gear Systems: Adjust gear ratios to increase output speed.
  • Rewind Motor: Modify the motor’s windings with fewer turns for higher speed.
  • Upgrade to a Higher Speed Motor: Replace with a motor designed for higher speeds.
  • Improve Power Supply Quality: Ensure stable and clean power supply.
  • Enhance Cooling: Upgrade cooling systems to prevent overheating.
  • Regular Maintenance: Keep the motor well-maintained and lubricated.
  • Optimize Control Settings: Fine tune VFD and control parameters for better speed performance.

Variable Speed Electric Motors

Winding Types (Variable Speed Electric Motors):

Variable speed electric motors may be wound in different ways to realize various operational parameters. Some of the winding types are;

  • Lap winding
  • Wave winding
  • Concentric winding

Each type has its benefits in the aspect of the amount of torque produced, power, size, and usable speed range. There are various types of winding, depending on the required application, and selecting the right one has a great impact on the best performance of the motor in any given application.

Operating Ways:

The variable speed electric motors can be controlled in a variety of ways depending on the application of the specific system. In an Open loop control system, it is possible to preset the motor’s speed so that it outputs depending on what is wanted.

Closed-loop control involves the use of a feedback system where sensors are used to detect the speed of the motor and timely modification is made accordingly.

One such technique to get rid of the external sensors is Sensorless control in which, the speed control is derived from the motor parameters.

Each of the operating methods has its benefits and the most suitable method is used depending on the requirements of the application.

Conclusion:

Variable speed electric motors are a pivotal component of today’s industrial and commercial applications and offer the best of both worlds, flexibility in speed and energy conservation. These motors’ working principles, parts, winding types, operating ways, and all other facts can be used by engineers and technicians to enhance their operation as per their numerous applications.

FAQs:

1. How does Variable Frequency Drive (VFD) control the speed of a variable speed electric motor?

A variable speed electric motor is controlled mainly through Variable Frequency Drive(VFD) through varying the frequency and voltage of power supplied to the electric motor. When it comes to the task demand or productivity it is possible to adjust the frequency of a motor and therefore run the motor at the appropriate speed which is needed.

2. What are the main constituents of a variable speed Electric motors?

They are stator, rotor, Variable Frequency Drive (VFD), bearings, shaft, cooling system, feedback sensors, control panel, windings and housing or enclosure. All the aforesaid parts have unique functions to perform so as the motor can run smoothly at different speeds.

3. Is it possible to make the speed of  the electric motor increase by increasing the voltage of  the supply?

Yes, it is acceptable to make changes to the voltages within the motors rated values and with a frequency of operation through VFD this can help increase the speed. But again one has to make sure that the volts should not go high than the motor voltage rating in a bid to cause damage.

4. What types of windings used in variable speed electric motors?

Variable speed electric motors can employ a range of windings for instance lap winding, wave winding as well as concentric winding. Each of them has different advantages as for the levels of torque, power, size and the range of speed for specific applications.

5. What are the Merits of using a sensor less control technique in variable speed electric motors?

The absence of sensors in driving the speed of the motor is the key to sensorless control method. This method also solves the problem of complexity by having an optimized system, and it also makes it cheaper, it is also believed to make it more reliable in the situation that maintaining sensors is difficult.