Thomas E. Murray was an American inventor, entrepreneur, and influential figure in electric utilities at the beginning of the 20th century. He left school at age nine when his father died to begin helping to support his family.
Working with Anthony N. Brady, he moved from Albany to New York City, and organized, consolidated, and expanded New York City's electrical generation and transmission systems. He oversaw the building of major power stations that powered the city for the first half of the 20th century. It is also referred to as sacrificial device, because it can perform this function only once.
Some of the most common fuses that are presently used in electronics are 3A, 5A and 15A. Today, circuit breakers are considered the better option, and so one-time-use fuses are no longer used for house wiring. But fuses are still being used in vehicles and electronic devices such as radios.
Thomas Edison is credited with the invention of the electrical fuse. He got its patent in and also built an electric power distribution system by using fuses. A fuse is formed by using a very thin metal strip in a protective glass that acts as a medium to disconnect load from power in case of a faulty electric circuit. Therefore, it disconnects the power supply from the connected system.
In normal operation of the circuit, fuse wire is just a very low resistance component and does not affect the normal operation of the system connected to the power supply. While selecting the proper fuse and its rated size for electrical appliances is based on different factors and environments. But the following basic formula shows how to choose the right size of fuse?
For example, you have to find the right size of fuse for 10A two pin socket. But you should go for the max i.
Different types of fuses can be categories on the following characteristics. Below is the brief explanation of the above categories. Current carrying capacity is the amount of current which a fuse can easily conduct without interrupting the circuit. Breaking capacity:. The value of maximum current that can safely be interrupted by the Fuse is called Breaking Capacity and should be higher than the prospective short circuit current.
Expect the current capacity of current, there is the maximum voltage rating a fuse can handle safely. Each fuse has maximum allowed voltage rating, for example, if a fuse is designed for 32 volts it cannot be used with volts, different amounts of isolation is required in different fuses working on different voltage levels. The I 2 t terms related to fuse normally used in short circuit condition. It is the amount of energy which carries the fuse element when the electrical fault is cleared by the fuse element.
The speed at which the fuse blows, depends on the amount of current flowing through its wire. The higher the current flowing through the wire, faster will be the response time. Response characteristic shows the response time for an overcurrent event.
Fuses which respond rapidly to the over current situation is called ultra fast fuses or Fast fuses. They are used in Many semiconductor devices because semiconductor devices are damaged by over current very rapidly.
There is another fuse which Is called a slow burn fuse , switch fuses do not respond rapidly to the over current event, but blow after several seconds of over current occurrence. Such fuses found their application in motor control electronics systems because motors take a lot more current at starting than running.
As we have mentioned above, AC and DC fuses have a little bit different packaging type, in the same way different applications require different packages to be used accurately in the circuit. One time use fuses contain a metallic wire, which burns out, when an over current, over load or mismatched load connect event occurs, the user has to manually replace these fuses, switch fuses are cheap and widely used in almost all the electronics and electrical systems.
On the other hand, the Resettable fuse automatically reset after the operation when fault occurs at the system. In the Current limiting fuse, they produce high resistance for a very short period while the non — current limiting fuse produces an arc in case of high current flow to interrupts and limit the current in related and connected circuits.
There are different types of fuses available in the market and they can be categories on the basis of Different aspects. Click image to enlarge. Fuses can be divided into two main categories according to the type of input supply voltage. In a DC system, when the metallic wire melts because of the heat generated by the over current, then Arc is produced and it is very difficult to extinguish this arc because of DC constant value.
So in order to minimize the fuse arcing, DC fuse are little bigger than an AC fuse which increases the distance between the electrodes to reduce the arc in the Fuse.
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