The Different Types of Circuit Protection

 

When it comes to circuit protection, there are several types of devices that you can use. MCBs, Resettable Fuses, TVS Diodes, and Chokes are just a few of these. Each of them has a different function. In this article, we will look at some of the different types of circuit protection and how they work. After reading this article, you should be able to choose the best circuit protection system for your needs.

Resettable Fuses

Resettable Circuit Protection fuses can be used in a wide range of applications. Their function is to protect electronic equipment from damaging overcurrent, short-circuit, and over-temperature conditions. They are also characterized by being field-replaceable and cost-effective. Listed below are some of their most common uses. Read on to learn more about their features and benefits. Whether they're the best choice for your application depends on the voltage and current required for your circuit.

Resettable fuses are generally designed to operate at a temperature less than their maximum operating current. When they're heated, their materials undergo a unique transformation, changing from a crystalline to an amorphous phase. This change increases the impedance. In this way, the material undergoes a circuit trip at the material's transformation, protecting the load from an overcurrent event.

MCBs

MCBs are used in electrical circuits for their short-circuit and overload protection. They are useful in industrial applications such as IT systems. The trip at a specific rate, typically 5 to 10 times the full load current. MCBs can be rated for different types of loads, and their short-circuit and load current ratings must be properly matched to the equipment they protect. The IET Wiring Regulations provide detailed guidance on how to choose the correct MCB for your application.

MCBs can be of two types: Type C and Type D. Both types protect against short-circuits, and Type C and Type D are designed to protect against high-inrush currents. Type D and Type K MCBs are rated at up to 20 times the full-load current, but they are generally slower. In some cases, Type K MCBs are better suited to protect cables without increasing the risk of nuisance tripping.

TVS Diodes

To choose the best TVS Diode for circuit protection, consider the following guidelines. To select the most appropriate TVS, consider the electrical characteristics of the circuit. The type of transient should also be considered. Voltage overshoots caused by a lightning strike will be different from those induced by a change in load or a non-perfect voltage relation. Temperature also plays a role in selecting the best device. The power rating of TVS Diodes decreases with increased temperature.

The breakdown voltage is the maximum voltage that a TVS diode will allow to flow to the ground. It is the voltage over which TVS Diodes will provide transient protection. The breakdown voltage should be slightly higher than the reverse stand-off voltage. This helps to ensure faster protection. To determine the breakdown voltage of your TVS Diode, look for a graph indicating the maximum power dissipation versus temperature (VBR).

Chokes

The function of a choke in a circuit is to prevent high-frequency signals from getting into the circuit and causing damage. It is also used in the design of automotive CAN buses, which allow various devices to communicate without requiring a host computer. Chokes are used in this type of circuit to prevent the peaks in current that occur at the output of a variable frequency drive or servo motor due to pulse-width modulation.

A choke can stop unwanted noise from entering electronic circuits by acting as an inductor and raising the impedance of the circuit. Chokes can be either common mode or ferrite. Chokes in a circuit can also be used to filter electromagnetic interference. Chokes are common in many different industries, including LCD panels, computers, monitors, USB cables, and communication microcontrollers. It's important to note that common-mode chokes are made to resist a wide range of frequencies.

When it comes to circuit protection, there are several types of devices that you can use. MCBs, Resettable Fuses, TVS Diodes, and Chokes.#circuitprotection #circuits #electronics #electroniccomponents pic.twitter.com/eTs9YmNMLv

— Joddie Marshall (@joddie_marshall) April 30, 2022

Thermal Switches

There are several types of circuit protection with thermal switches. Some are compact, and some are magnetic. Generally, compact switches are designed to protect magnetic fields. They contain contacts of various materials, but the hardest is made of wolfram alloy. The softer materials are made of silver, graphite, or a combination of the two. Thermal magnetic switches are excellent options for circuit protection in a variety of applications. When choosing a thermal-magnetic switch, make sure to consider the quality.

A simple thermal-protection circuit includes two temperature switches. The resistances set the thresholds. These temperature switches connect to the inputs of a dual-input OR gate. If there are multiple hot spots, more temperature sensors can be added. The OR gate will then crowbar the power supply or blow a fuse if the temperature exceeds a predetermined limit. It may be necessary to install several temperature sensors to protect multiple hot spots.