We are Apogeeweb Semiconductor Electronic


Home arrow Fuse arrow What Are the Two Major Types of Fuses?

arrow left

arrow right

What Are the Two Major Types of Fuses?

Author: Apogeeweb
Date: 19 Jan 2021
what are fuses made of


In electronics and electrical circuit, a Fuse is an electrical safety device that operates to provide overcurrent protection. In order to stop the damaging effects of overcurrent, when too much current flows through the low resistance element of the fuse, the element melts and breaks the circuit, because a special feature of the fuse is that it contains a piece of wire that melts easily. Fuses are widely used for protection of electric motor circuits with different types. Before you read the following note, you can think about a question: what are the types of fuses and its uses?

What is an Electric Fuse? and How to Prevent Short Circuit with Fuses?



Ⅰ Fuse Basic Overview

1.1 What Are Fuses

1.2 Fuse Working Principle

1.3 Electrical Fuse Symbol

1.4 Fuse Materials

Ⅱ Electric Fuse Classification

2.1 DC Fuses Basic

2.2 AC Fuses Basic

Ⅲ Conclusion

Ⅳ Frequently Asked Questions about Fuse Types Basics and Its Applications

Ⅰ Fuse Basic Overview

1.1 What Are Fuses

An electrical fuse is a protection device built around a conductive strip that is designed to melt and separate in the event of excessive current. In other words, what are fuses for? The fuse breaks the circuit if a fault in an appliance causes too much current to flow. Except that, fuses are essentially temperature-sensitive devices. Even small variations from the controlled test conditions can greatly affect the predicted life of a fuse.

1.2 Fuse Working Principle

The primary task of a fuse is to split the circuit if the circuit draws a current higher than desired, thus avoiding the harm due to short circuits.
The simplest fuse type consists of a resistive part, carefully chosen for its melting point. A slight voltage drop (small enough so that the circuit downstream will not be impacted) is generated across the element when a current passes through this element, and some power is dissipated as heat. Thus, the element's temperature increases. This temperature rise is not necessary for normal currents to melt the filament. However, the melting point is easily reached if the current draw reaches the nominal current of the fuse. The resistive part melts and is disrupted by the circuit. The nominal current is determined by the thickness and length of the resistive material.
To provide predictable trip currents, fuse components are made of zinc, copper, silver, aluminum, or other alloys. Over time, the element must not oxidize or corrode.

1.3 Electrical Fuse Symbol

What is the symbol of fuse? different fuse symbols in the electrical circuit diagram showed below.

fuse symbols

Electronic Symbols of Fuse

1.4 Fuse Materials

What are fuses made of? The material used for making fuse elements has a low melting point such as tin, lead, or zinc. A low melting point is, however, available with a high specific resistance metal shown in the table below. The material mainly used for fuse elements are tin, lead, silver, copper, zinc, aluminum, and an alloy of lead and tin.


Ⅱ Electric Fuse Classification

After you know what is a fuse in a circuit, the following are the types of fuse. There is a wide selection of PCB fuses in the market. Here introduce two major types: AC fuses, and DC fuses. The following note describes different types of fuses and their constriction, working characteristics.

Types of Fuse Explained

2.1 DC Fuses Basic

  • Cartridge Fuses

This is the fused form that is the most common. In a glass envelope that is terminated by metal caps, the fuse part is encased. In a suitable holder, the fuse is mounted. As the glass envelope is transparent, whether the fuse is blown, it is easy to visually determine.
This style has many versions, including the slow blow fuse and the quick blow fuse. Slow blow fuses have a larger element that can handle overcurrent and are unaffected by spikes in the appliance for a relatively short period of time. Quick blow fuses respond to existing spikes instantly.
To withstand elevated temperatures, some versions of this fuse are encased in ceramic. Sand or oil is packed with fuses for high voltage applications. This is to stop arcing after it has blown between the two ends of the fuse. For direct PCB mounting, SMD variants of cartridge fuses also exist.


  • Automotive, Blade Type & Bolted Type Fuses

These fuses are designed especially for automotive systems running up to 32V and 42V at times. They come in the form of a 'sword' (a transparent plastic envelope with flat contacts) and are color-coded according to the nominal current. In other high-power circuits, some of these types are also used.


  • Resettable Fuses/Polyfuse

These fuses are self-resetting, much as their name suggests. They contain black particles of carbon embedded inside organic polymers. The carbon black usually renders the mixture conductive. Heat, which expands the organic polymer, is created when a large current flows. The black particles of carbon are pulled apart, and conductivity decreases to the point that there is no flow of current. As temperatures decrease, conductivity is restored. The fuse does not, however, have to be replaced physically. This type of fuse is often referred to as a PTC, which means a positive temperature coefficient since the temperature rises with resistance.
For computer power supplies and phone chargers, the PTC Fuse is ubiquitous. They are particularly handy here because it is difficult to replace them. They are used in aerospace devices for the same purpose.
In their through-hole variants, PTCs are easily recognized by their yellow-orange colour and disc (and sometimes rectangular) form. With white markings, SMD poly fuses normally come in green or with gold markings in black. Virtually every current rating offers PTCs.


  • Semiconductor Fuses

With current flow, the power dissipated by a semiconductor increases exponentially, and semiconductors are thus used for ultrafast fuses. These fuses are commonly used to secure devices that are susceptible to even minor current spikes from semiconductor switching.


  • Overvoltage Suppression Fuses

Voltage spikes may also often be dangerous to circuits, and with a fuse, an overvoltage safety system is also used to protect against both voltage and current spikes.
There are NTCs (negative coefficient of temperature) put in parallel with the supply. NTC Fuses minimize resistance due to higher current flow and absorb spikes when the supply voltage spikes.
Semiconductor-like devices that bidirectionally absorb voltage spikes are metal oxide varistors (MOVs). Using the linked post, you can learn more about MOV and its work.

types of fuses

2.2 AC Fuses Basic

  • High Voltage Fuses

In high voltage AC transmission lines, these fuses are used where voltages can exceed several hundred kilovolts.
1) HRC (High Rupture Current) Fuses
HRC fuses are fuses of a cartridge type consisting of a transparent steatite envelope (magnesium silicate). The fuse is packed with quartz powder that serves as an arc extinguishing agent (and, in the case of a liquid-filled HRC fuse, a non-conducting liquid like mineral oil).
2) Expulsion Fuses
These fuses are packed with chemicals such as boric acid, which creates heating gases. The arc is extinguished by these gases and ejected from the ends of the fuse. Copper, tin, or silver are made of fuse material.


  • Low Voltage Fuses

The low voltage fuses are divided into five types and those are rewirable, cartridge, drop out, striker, and switch fuses.

1) Rewireable Fuses
They are a quick fuse used in homes and offices that is reusable. A carrier and a socket are composed of them. The carrier is taken out, rewired and placed back in the socket when the fuse is blown, to restore normal service. They are slightly less effective than fuses from HRC.

2) Cartridge Fuses
They are very similar to DC fuses for cartridges. A transparent envelope covering the part of the fuse consists of them. It is possible to plug them in (blade type) or screw them into a fixture (bolt type).

3) Drop Out Fuses
They contain a spring-loaded lever arm that retracts when a fault occurs and must be rewired to restore normal service and put back in place. They are a form of fuse for expulsion.

4) Striker Fuses
 A spring-loaded striker is provided with these fuses that can serve as a visual indication that the fuse has exploded and other switchgear is also triggered.

5) Switch Fuses
High current fuses can be attached or disconnected by a handle that is manually controlled.

electrical fuses display

Ⅲ Conclusion

In the field of electronics or electrical, the fuse is a small safety part in an electrical device or piece of machinery. It is considered the most crucial device which is employed in various electrical circuits. Many types of fuses with stock availability in the business can meet various circuit requirements.


Ⅳ Frequently Asked Questions about Fuse Types Basics and Its Applications

1. What are fuses?

Fuses are sacrificial devices used to protect much more expensive electrical components from the damaging effects of overcurrent. They consist of a low-resistance metal or wire that is used to close a circuit.


2. What are the types of fuses?

Different Types of Fuses – Constriction, Working & Characteristics
DC Fuses
AC Fuses
Cartridge Fuses
D – Type Cartridge Fuse
HRC (High Rupturing Capacity) Fuse or Link Type Cartridge Fuse
High Voltage Fuses
Automotive, Blade Type & Bolted Type Fuses
SMD Fuses (Surface Mount Fuse), Chip, Radial, and Lead Fuses


3. Where are fuses used?

Fuses are widely used for protection of electric motor circuits; for small overloads, the motor protection circuit will open the controlling contactor automatically, and the fuse will only operate for short circuits or extreme overload.


4. How many types of fuses are there?

Fuses can be divided into two major categories, AC fuses, and DC fuses.

5. What is the difference between Fuse and MCB (miniature circuit breaker)?

Fuse is an electrical device that self-destructs and stops the current flow in a circuit whenever the current exceeds the predefined value. MCBs are resettable circuit protection devices that, on the occurrence of faults, stops the current flow in a circuit.


6. How do I know what fuse to use?

You'll usually find the fuse rating on the side of your fuse, which will be given in amps. The fuse rating is the amount of current needed for the fuse to blow or break. When this happens, it stops the electrical power from flowing through the electrical circuit.


7. What are the different types of fuses?

The fuse is the current interrupting device that breaks or opens the circuit by fusing the element and thus removes the faulty device from the main supply circuit. The fuses are mainly classified into two types, depends on the input supply voltages they are the AC fuses and the DC fuses.


8. What is the difference between AC and DC fuses?

With AC circuits, the current is crossing the zero potential at 60 or 50 cycles a second. This helps in breaking the arc that forms when the fuse element melts and creates a gap. In dc circuits, the voltage does not go to a zero potential, making it more difficult to suppress the arc in the melting element's gap.


9. What is the difference between T and TL fuses?

The difference between SL and TL fuses is their bases. An SL is a rejection base, while a TL is your typical edison base. The difference between S and T fuses is the same. SL and TL fuses are Loaded Link and are normally used in special, lighter applications, while S and T are used in heavier applications.


10. How do fuses protect us?

The fuse breaks the circuit if a fault in an appliance causes too much current to flow. This protects the wiring and the appliance if something goes wrong. The fuse contains a piece of wire that melts easily. If the current going through the fuse is too great, the wire heats up until it melts and breaks the circuit.


Best Sales of diode

Photo Part Company Description Pricing (USD)
A3967SLBTR-T A3967SLBTR-T Company:Allegro MicroSystems Remark:IC MTR DRV BIPOLAR 3-5.5V 24SOIC Price:
1000+: $1622.60000
A3985SLDTR-T A3985SLDTR-T Company:Allegro MicroSystems Remark:IC MTR DRV BIPOLR 12-50V 38TSSOP Price:
4000+: $3.66250
A8483EEKTR-T A8483EEKTR-T Company:Allegro MicroSystems Remark:IC REG BOOST ADJ 350MA 5TDFN Price:
AS6C4008-55ZIN AS6C4008-55ZIN Company:Alliance Memory, Inc. Remark:SRAM - Asynchronous Memory IC 4Mb (512K x 8) Parallel 55ns 32-TSOP II Price:
1+: $4.47000
10+: $4.05200
25+: $3.96400
40+: $3.94250
117+: $3.53496
234+: $3.52209
468+: $3.39340
1053+: $3.22608
4914+: $2.87001
ADSP-2181BSZ-133 ADSP-2181BSZ-133 Company:Analog Devices Inc. Remark:IC DSP CONTROLLER 16BIT 128QFP Price:
1+: $54.00000
10+: $507.32000
25+: $1227.38000
100+: $4745.85000
ADSP-BF700KCPZ-2 ADSP-BF700KCPZ-2 Company:Analog Devices Inc. Remark:IC DSP LP 128KB L2SR 88LFCSP Price:
1+: $11.78000
10+: $10.64300
25+: $10.14760
100+: $8.81100
250+: $8.41500
500+: $7.67250

Alternative Models

Part Compare Manufacturers Category Description

Ordering & Quality

Image Mfr. Part # Company Description Package PDF Qty Pricing (USD)
DAC8413BTC-883C DAC8413BTC-883C Company:Analog Devices Inc. Remark:IC DAC 12BIT QUAD V-OUT 28CLCC Package:N/A
In Stock:On Order
1+: $507.94000
AD5522JSVDZ AD5522JSVDZ Company:Analog Devices Inc. Remark:IC PPMU 80TQFP Package:80-TQFP Exposed Pad
In Stock:199
1+: $65.79000
10+: $62.50200
25+: $60.85760
AD8038ARZ AD8038ARZ Company:Analog Devices Inc. Remark:IC OPAMP VFB 1 CIRCUIT 8SOIC Package:8-SOIC (0.154", 3.90mm Width)
In Stock:7341
1+: $2.60000
10+: $2.33200
25+: $2.20000
100+: $1.76000
250+: $1.54000
500+: $1.49600
1000+: $1.27600
AD9680BCPZ-1250 AD9680BCPZ-1250 Company:Analog Devices Inc. Remark:IC ADC 14BIT PIPELINED 64LFCSP Package:64-WFQFN Exposed Pad, CSP
In Stock:7
1+: $1028.12000
ADAU1772BCPZ-R7 ADAU1772BCPZ-R7 Company:Analog Devices Inc. Remark:IC CODEC LOW PWR 24BIT 40CSP Package:40-WFQFN Exposed Pad, CSP
In Stock:On Order
750+: $7.14851
ADUC848BSZ8-5 ADUC848BSZ8-5 Company:Analog Devices Inc. Remark:IC MCU 8BIT 8KB FLASH 52MQFP Package:52-QFP
In Stock:384
1+: $10.90000
10+: $10.01700
25+: $9.60160
100+: $8.45970
250+: $8.04452
500+: $7.52550
REF195GSZ-REEL REF195GSZ-REEL Company:Analog Devices Inc. Remark:IC VREF SERIES 0.2% 8SOIC Package:8-SOIC (0.154", 3.90mm Width)
In Stock:2500
AD8628WARZ-RL AD8628WARZ-RL Company:Analog Devices Inc. Remark:Zero-Drift Amplifier 1 Circuit Rail-to-Rail 8-SOIC Package:8-SOIC (0.154"", 3.90mm Width)
In Stock:On Order
181+: $1.38320

Related Articles

pinglun 0 comment

Leave a Reply

Your email address will not be published.

code image
Rating: poor fair good very good excellent

# 0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z