Electronic Resistor Distributor
- Available in 5 power ratings from 1 ohm to 10 ohms.
- Low cost and combined with high reliability.
- Use in most types of circuits, including audio, communications, measurement and computer applications.
- Highly voltage resistors with ultra-high working voltage up to 10,000V and anti-surge capability.
Any Types of Electronic ResistorJust Send us Your Part Number,We'll Quote You Within 8 Hours
Reputed Electronic Resistor Supplier - Rantle East Electronic
RANTLE Electronic Resistor are premium quality carbon film resistors whose ceramic core has a high alumina content offering power to size ratios not normally associated with carbon film product. Electronic resistors are available in 5 power ratings from 1 ohm to 10 ohms. It has the smallest case size which has a full 0.25 W power rating.
RANTLE Electronic Resistor is a low cost, combined with high reliability, make these components suitable for use in most types of circuits, including audio, communications, measurement and computer applications.
RANTLE electronic Resistor is suitable for high voltage power supply, audiophile speakers, medical electronical devices, audio systems, smoke sensors, infrared detectors, and radiation detectors.
RANTLE Electronic resistors are highly voltage resistors with ultra-high working voltage up to 10,000V and anti-surge capability. It has two terminal extensions that are fixed on both ends of a ceramic tube on whose surface winds wave-shaped alloy resistance wire and a high temperature-resistant and fireproof coating are applied. This electronic resistor can be customized to special needs of customer and applicable to simulation load test, equipment discharge, automated control and inverter’s energy loss brake.
RANTLE Electronic Resistor features ultra-high stability resistors, ultra-low temperature coefficient to ±1ppm/ºC, ultra-high reliability resistors, ultra-high precision resistors, ±0.01%, mold type, T0220 encapsulation, and ultra-high reliability resistor.
RANTLE deals many parts of Electronic Resistor with almost 15 years of service. If you choose us, RANTLE can assures you strong source of Electronic Resistors. We promise that RANTLE East Electronic is your most trustworthy and reliable electronic components supplier!
We offer swift delivery of your orders. What are you waiting for? Avail our one of a kind electronic resistor now! We warmly welcome people from all over the world to contact and cooperate with us. We will become long-term business partners and build a splendid future together.
Electronic Resistor: The Ultimate FAQ Guide
This guide covers everything you would like to know about electronic resistor.
Whether you want to learn about components, working principle, classification, or connection, you will find everything here.
Take a look:
- What is an Electronic Resistor?
- What is Inside an Electronic Resistor?
- How does an Electronic Resistor Work?
- What are the Types of Electronic Resistors?
- Where are Electronic Resistors used?
- How do you Test Electronic Resistor?
- Is an Electronic Resistor Polarized?
- What is an Electronic Resistor Wattage?
- How much Current can an Electronic Resistor Handle?
- Which Electronic Resistor is used with LED?
- Do Electronic Resistors change the Voltage?
- Why would an Electronic Resistor Burn out?
- Can you use a Higher Wattage Electronic Resistor?
- Is a Wire an Electronic Resistor?
- What is a Photoresistor?
- What is the Electronic Resistor Color Code?
- What is the Power Rating of an Electronic Resistor?
- How are Electronic Resistors Connected?
- Why are some Electronic Resistors Encased in Ceramic?
- Is a Fuse an Electronic Resistor?
- What is Wire Wound Resistor?
- Does Electronic Resistor increase Battery Life?
- What are some Electronic Resistor Characteristics?
- Can you Interchange Surface Mounted Resistors with Through-hole Resistors?
- What are SMD Resistors?
- Are MELF Resistors SMD Resistors?
- Is a Thermistor a Resistor?
- How does a Varistor Work?
What is an Electronic Resistor?
An electronic resistor is a passive electrical component used in circuits to restrict current flow.
The electronic resistor is made with a defined value of electrical resistance.
Electrical resistance is the tendency of a material to resist the flow of electric current.
An electronic resistor is rated in ohms.
The ohm is also the standard unit for measuring electrical resistance.
What is Inside an Electronic Resistor?
You find electronic resistors are made from conductive films that exhibit resistivity.
These films could be made from metallic compounds or carbon.
The films are then covered by layers of a non-conductive material such as ceramics or glass.
Other electronic resistors such as the wire-wound resistor are made by coiling a wire around a non-conductive core.
Surface-mounted resistors are made by using thin or thick films of alloys of metal to offer resistance to current flow.
Ceramic or glass is then used to shell the film.
You find that electronic resistors are constructed differently depending on the intended use. Electronic resistors meant for use in elevated temperature conditions or for power applications will differ from normal use resistors.
How does an Electronic Resistor Work?
An electronic resistor works on the principle of Ohm’s law.
This law postulates that the voltage across a conductor is directly proportional to its electrical resistance and current flow.
This way, you find that an electronic resistor can be used to vary the voltage amount in a circuit.
What are the Types of Electronic Resistors?
Types of resistors
There are several types of electronic resistors available.
Electronic resistors are fabricated in different ways in order to meet different application needs.
You will also find resistors as either through-hole or surface mounted.
Through-hole resistors have extended leads that enable them to be stuck into holes or soldered onto boards.
Surface-mounted transistors have flattened connective edges.
They are rested flat on the circuit board over pads with contact points.
However, you find electronic transistors broadly classified into fixed or variable resistors. Variable resistors have a standard resistive film or wire alongside a slider.
The slider is attached to the film/wire, providing a third point of connection.
When the slider is employed alongside the other two connections, it acts as an adjustable voltage divider.
Employing the slider and a single connection point allows you to vary the component’s resistance value.
The fixed resistor differs from the variable resistor by the lack of a slider, thereby having only two connection points.
These resistors have a predetermined resistance value that cannot be adjusted.
They are also more popular in use compared to variable resistors.
You will find variable resistors with many different configurations to suit different applications.
However, two common types you will find are the adjustable variable resistor and the preset variable resistor.
The preset variable resistor is also called the potentiometer.
The adjustable variable resistor is configured with a screw allowing it to be adjusted via turning a knob.
Most electronic controls, such as volume, utilize such a resistor.
The potentiometer values are set during manufacture, only allowing you to shift within the set values.
The resistive element in variable resistors can be made from carbon, a metal/ceramic combination, conductive plastic, or be wire-wound.
Additionally, the slider could be linear, like a scale or rotary like a clock hand.
Variable resistors, read potentiometers, find myriads of use in electrical appliances.
They are sued for volume controls in radios and as control knobs in appliances such as microwaves and washers.
Some common types of fixed resistors include:
· Carbon Composition Resistor
Currently unable to find use in modern equipment, the carbon composition resistor consists of a carbon-based resistive element.
It found use in a variety of circuits such as surge protection and current limiting, alongside high-frequency applications.
This type of resistor was popular for its tolerance to elevated energy pulses.
Additionally, combining the resistive element with non-conducting material such as ceramics provided more energy absorption levels.
With this, safe absorption of high transients is possible.
Use of the carbon composition resistor declined due to the following reasons:
- Using the carbon composition resistor is accompanied by noise.
- This resistor type has poor stability, with the resistance value changing over time.
- The temperature coefficient of resistance of the carbon composition resistor is high, reaching over a thousand parts-per-minute per degree centigrade.
· Carbon Film Resistors
This type of fixed resistor is has a film of carbon for a resistive element that is encased in a ceramic compound.
This resistor was a design improvement on the carbon composition resistor allowing better performance levels.
Also, the carbon film resistor has a helical incision on the film to allow alteration of the resistance value.
As a result, the film is narrowed, and length increased, affecting their inductive level and consequent use in frequency applications.
Carbon film resistors are available with different tolerance levels allowing use in a wide range of applications.
They also have a better temperature coefficient of resistance than the carbon composition resistors.
· Metal Oxide Film Resistor
The resistive element in the metal film oxide resistor is an oxide of metal that is deposited onto a ceramic core.
Also, the most common metal oxide used was an oxidized chloride compound of tin.
Like the carbon film resistor, it features a helical incision to improve resistivity.
Metal oxide film resistors have a wide tolerance range with a high operating temperature rating.
Additionally, they have low noise levels than the carbon film resistor and better stability.
· Metal Film Resistors
The metal film resistor replaces the metal oxide film with a metal film. However, it is similar in design to the metal oxide film resistor.
This resistor type has improved stability and reliability than the previous resistor types.
These transistors have close tolerance values allowing their use in circuits requiring consistent resistance value.
Their temperature coefficient of resistance is also low, allowing stability with an increase in temperature.
Besides, they work almost quietly with minimal noise.
Metal film transistors are commonly used in general applications requiring electronic transistors.
However, they have low endurance levels for transients and exhibit minimal resistance to current flow changes.
· Wire Wound Resistors
These resistors constitute a conductive wire wrapped around a non-conductive core, usually of ceramic material.
The wire coil is welded to provide a single surface finish.
Besides, the assemblage is thereafter enclosed to protect the wire-wound from atmospheric elements such as humidity.
The design of the wire-wound resistor allows you to adjust its resistance level.
You can use a material with a desired resistivity for the wire, and alter its length and thickness. This allows the wire-wound resistor existence as two functional types: precision resistors and high power resistors.
By leveraging on a close tolerance margin, the wire-wound resistor can be furnished as a precision resistor.
This way, it finds use in applications requiring fine margins of operations. Such applications include measurement devices and calibration equipment.
Power wire wound resistors are based on the wire-wound resistor ability to dissipate high power without failure.
Additionally, their low temperature coefficient of resistance and high working temperature instigate their use as such.
Additionally, the wire-wound resistor has the following winning characteristics:
- It works silently with reduced noise levels.
- They have very narrow tolerance margins that allow for their use in fine applications such as making measurement devices.
- Their low temperature coefficient of resistance makes them stable in performance.
- Wire wound resistors can endure high degree pulses and energy levels.
- By altering the type of wire material, length, and thickness, wire wound resistors are perfect for customization.
Where are Electronic Resistors used?
You find the following common uses for electronic resistors:
· Dividing Voltage
Sometimes the voltage supplied in a circuit is greater than is needed.
In this instance, electronic resistors are used to reduce the voltage amount.
The reduction of the voltage amount is made possible by sharing the voltage out among multiple electronic resistors connected in series.
· Timing Application
Electronic capacitors are used to supply energy in timing functions.
However, timing applications such as flashlights for port signals require certain current amounts for certain signal combinations.
The electronic capacitor lacks current flow control capacity.
An electronic resistor is therefore used to control the amount of current flow.
The time an electronic capacitor takes to charge can, therefore, be controlled in this way.
· Heating Applications
A notable by-product of electrical resistance is heating.
When an electronic resistor is provided a high resistivity, it generates large amounts of heat that could be harnessed for other purposes.
For tungsten, this heat is used to generate light. In heaters, it is used to supply hot water.
· Current Control
Some electrical components require a limited range of electrical currents in order to function.
These components, such as light-emitting diodes and electronic transistors, can fail or get damaged when current levels exceed this range.
Electronic resistors are used to stabilize electrical current inflows to these components.
This is because electronic resistors can be used to vary the voltage across the path of current flow.
· Circuit Control
Electronic resistors find use in circuits to achieve certain functions by virtue of their resistivity. For example, variable resistors are used in circuits for signal amplifiers, where they can be used to increase signal power. Besides, they can also be used to adjust motor speeds.
How do you Test Electronic Resistor?
The following process is helpful when you want to test an electronic resistor:
First, you need to disconnect an electronic resistor from its host circuit.
You do this by cutting the power supply to the circuit and then physically removing the resistor.
You then identify the resistor value by reading its surface or, if not indicated, deciphering its color code.
Additionally, you need to determine its tolerance value. This will help you in comparing your test value.
You then connect the resistor to a digital multimeter that is set to measure resistance values.
Remember to set the meter to a higher figure than the electronic resistor’s maximum expected resistance value.
Record the value shown on the multimeter’s display with your electronic resistor’s tolerance range.
For a functional resistor, the displayed value should be within its tolerance range. Otherwise, it indicates a malfunctioned electronic resistor.
Is an Electronic Resistor Polarized?
No, it is not.
Electronic resistors have leads that do not adhere to polarity.
Electronic resistors are used to restrict current flow in a circuit.
As such, they are, in essence, a part of the circuit, with the difference being the uniqueness of this part.
Here, high resistance levels are exhibited to control current or voltage inflows into another circuit component.
What is an Electronic Resistor Wattage?
Electronic resistor wattage is a rating that describes the maximum quantity of power that an electronic resistor can tolerate.
This wattage is also described at a defined optimum temperature or range.
When an electronic resistor impedes current flow, heat is generated.
This heat is a form of energy that is measure in watts.
An electronic resistor can bear the heat produced up to a certain provided level beyond which it burns out.
How much Current can an Electronic Resistor Handle?
The amount of current an electronic resistor can handle is dependent upon its power rating.
Also, the electronic resistor will receive current inflows until the power limit is exceeded.
Excess current will cause the electronic resistor to burn up.
You can determine an electronic resistor’s maximum current by using the rated power value and its resistance value.
This is through the relationship; power is equal to the square of current and resistance.
Which Electronic Resistor is used with LED?
The voltage-current-resistance relationship is helpful in determining which electronic resistor to use with an LED.
To establish the resistance value, you divide the working voltage over the LED’s operating current.
The voltage amount, in this case, is determined by the operating voltage of the setup.
You get the operating voltage by subtracting the LED’s forward voltage from that of the battery source.
The current amount is provided as the operating current rating of the LED.
Do Electronic Resistors change the Voltage?
You find that the value of an electric resistor will determine the voltage amount given a specific operating current.
This is because the voltage in a circuit is directly related to the resistor value at a defined current.
Why would an Electronic Resistor Burn out?
Electronic resistor burn out
An electronic resistor will burn out as a result of dissipating more heat energy than it can withstand.
Electronic resistors release energy in the form of heat when in operation.
This is usually dependent on the voltage or current supply.
Manufactures provide a rating describing the maximum amount of power that an electronic resistor can discharge without failing.
When an electronic transistor is operated beyond this value, it burns out.
Can you use a Higher Wattage Electronic Resistor?
Yes, you can.
You can replace an electronic resistor with one with a higher wattage.
This will be useful in instances where there are surges in voltage.
Spikes in voltage will usually result in the dissipation of more heat when a transistor is in operation.
Electronic resistor wattage
Is a Wire an Electronic Resistor?
A wire by itself is not an electronic resistor. Even though being a conductor, it will exhibit minimal resistance to the flow of current within it.
However, a wire can be coiled around an insulating core from a wire wound resistor.
Such a resistor is useful in applications requiring precision and high power.
The material of the wire, its thickness, and length will determine the resistive properties of the resistor.
What is a Photoresistor?
The photoresistor is a special type of resistor, also called the light-dependent resistor.
It is used for light sensing applications and to alter circuit settings, given the intensity of light.
This is typically by changing the resistance values.
The photoresistor is made from a photosensitive semiconductor material that provides high resistance to electron flow.
However, light energy is able to break down the resistance, and the more the intensity, the less the resistance.
Photo resistor circuit
A photoresistor can either be extrinsic or intrinsic.
Intrinsic photo resistors use pure semiconductor materials such as silicon and germanium.
While extrinsic photoresistors use doped semiconductor materials.
The doping of semiconductors involves the addition of external elements to improve certain properties of the semiconductor.
Photoresistors are easily available due to their low pricing.
They find use in light sensing applications such as light alarms.
Also, they can also be used in circuits controlled by light intensity, for instance, in street lighting.
Additionally, you find photoresistors are employed in photodetectors due to their ability to synthesize wavelengths.
Radiation levels in the atmosphere can also be deciphered by photoresistors.
What is the Electronic Resistor Color Code?
The electronic resistor color code is a color convention used to identify the resistance value of electronic resistors.
This is especially true for through-hole electronic resistors.
Also, this convention includes the marking of electronic transistors with colored bands.
These bands represent value and need to be decoded by the use of a colour chart.
There are electronic resistors with four, five, and six bands.
The four-band is the most common.
Electronic resistor color code
Electronic Resistors with Four Bands
With four-band electronic resistors, the first band pair provides the digits for the resistor’s ohmic rating.
You have to interpret the digits alongside the third band, which provides a figure to multiply with.
The third band is, therefore, multiplier.
When you multiply the two-digit value with the multiplier value, you get the electronic resistor’s value in ohms.
The last band informs on the electronic resistor’s tolerance as a percentage.
Tolerance provides for how much the actual resistor value will deviate from the rated value.
The bands are arranged such that the last band, the tolerance band, is quite apart from the other bands. This helps you in determining the band positions.
Electronic Resistors with Five and Bix bands
The fifth band in the five band electronic resistors provides an additional digit to the two-digit combination in four bands.
Otherwise, the information remains the same.
Electronic transistors with six bands are basically just five-band transistors but with an extra band after the tolerance band.
This extra band provides information on the electronic resistor’s temperature coefficient.
The temperature coefficient is useful in describing the relationship between the electronic resistor’s value with the changes in temperature.
What is the Power Rating of an Electronic Resistor?
The power rating of an electronic resistor is the maximum amount of power that it can endure without causing inherent damage to itself.
When a voltage or current is applied to an electronic resistor, heat is produced due to resistivity.
The resistor is made to tolerate this heat as it accumulates up to a certain threshold level. When this point is exceeded, there is a danger of the electronic resistor burning out.
How are Electronic Resistors Connected?
There are two ways in which you can connect electronic resistors: series and parallel. Connecting electronic resistors in parallel or series is useful in controlling the voltage or current amounts in a circuit.
Additionally, you can use a combination of both parallel and series arrangement in a single network.
A series connection involves the arrangement of individual electronic resistors in a single path.
This way, the same amount of current will flow through the electronic resistors in the circuit.
The total resistance value of a series arrangement is obtained by adding up the individual values of the electronic resistors.
A parallel connection has electronic resistors configured such that they all have individual paths for current flow.
This total resistance in this configuration is not straightforward.
First, you establish the inverse of the resistance value of individual resistors and sum them up. Total resistance is obtained by determining the inverse of the sum.
Why are some Electronic Resistors Encased in Ceramic?
You find ceramic is used to enclose some electronic resistors majorly for protection.
Ceramic is a tough compound making it difficult to break, thereby protecting the resistor from physical damage.
Ceramic electronic resistor
Additionally, you find the ceramic body protects the electronic resistor from harsh environments.
This includes high temperatures due to its high melting point. Furthermore, due to its limited reaction with chemical elements, it protects the resistor from chemical damage.
Is a Fuse an Electronic Resistor?
A fuse is a safety device used in electrical circuits to protect the circuit and other components from superfluous currents.
It works by terminating current flow in a circuit when there is an excess current.
It typically consists of a thin wire that melts when current is over the set limit.
When the fuse melts, it disconnects the circuit, thus preventing further flow.
This necessitates a replacement for the fuse or rewiring. As such, you cannot describe a fuse as an electronic resistor.
However, by limiting the flow of charge, an electronic resistor can function as a fuse.
When it experiences an increased charge flow and dissipates heat beyond its power rating, it will burn up.
This will destroy the resistor and cause a termination of the current flow.
What is Wire Wound Resistor?
Wire wound resistor
A wire-wound resistor is made by coiling a resistive wire around a non-conductive core.
This type of resistor is credited as the earliest form of a resistor.
For a wire wound resistor, its resistance will be determined by the resistivity of the wire, its thickness, and its length.
By tinkering with these parameters, you can determine desired resistance values.
Using a wire with a very thin and long wire with high resistivity will provide you a wire-wound resistor with a very high value of resistance.
This is impractical, rendering the wire-wound resistor best for low values of resistance.
The wire-wound resistor can be configured to serve precision functions and functions requiring high power.
Precision functions require high resistance values with a reduced tolerance range.
This is done by keeping the wire-thin and using more coils to increase wire length.
Power applications require low resistance value with large power output.
High power ratings, for instance, need the use of thicker wires to provide robustness.
The wires in wire wound resistors are mostly alloys due to their low temperature coefficient in relation to resistance levels.
Metals are employed when high temperatures, as a result of a change in resistance values, are desired.
This is true for application heating and lighting applications.
Does Electronic Resistor increase Battery Life?
Using an electronic resistor in a circuit reduces the charge flow.
The battery source will, therefore, supply a reduced voltage, allowing it to serve for a longer duration.
However, practically, an electronic resistor regulates charge flow for a secondary component.
As such, these secondary components require a certain amount of voltage to perform as intended.
Reducing the voltage to extend battery life might result in a component not working or working at a reduced level.
Consider a light bulb, which will produce dim light at voltages lower than its rated amount.
What are some Electronic Resistor Characteristics?
Electronic components usually have some parameters related to it.
These parameters give you some form of insight into a component’s properties.
Also, these characteristics are useful in helping you determine what component type to choose for your application.
The electronic resistor has many functions.
You can use the electronic resistor for current, circuit and voltage control, heating applications, and timing applications.
It follows that these functions will require different distinctive electronic transistor types.
To enable you establish what transistor you need to choose for a certain application, the following characteristic could be useful.
Characteristics of electrical resistor
· Resistance Value
The resistance value is the most important aspect you can consider on an electronic resistor.
This parameter is provided in ohms and is especially useful in applications of voltage or current control.
Additionally, some applications require specific resistance values.
Knowing the value of the electronic resistor you are purchasing should help you identify its correctness to a purpose.
Tolerance refers to the possibility of the electronic resistor exceeding the rated value or falling short of it.
This parameter is usually provided as a percentage of the rated value.
Applications requiring high precision will need an electronic resistor with low tolerance.
· Power Rating
When an electronic resistor is operational, there is bound to be heat generation.
This generation of heat is also affected by temperature.
When left unchecked, it could result in the damage of the electronic resistor.
An electronic resistor has a power rating in watts attached to it.
This informs you about how much power it is able to withstand before it faces the danger of failure.
While using an electronic resistor, you should be careful not to exceed this maximum rating of power.
An electronic resistor’s inductance is useful in determining an electronic resistor’s application in some instances.
Inductance is exhibited when a conductor attempts to resist changing amounts of electrical current flow.
The henry is the measurement unit of inductance.
High-frequency applications require electronics resistors with low inductance.
Surface-mounted resistors have low inductance levels compared to wire wounded resistors. Surface-mounted resistors are thus suited for high-frequency applications.
· Maximum Working Voltage
Electronic resistors are rated for the voltage with which they can be used.
When this happens, you are only allowed to use an electronic resistor under the maximum voltage indicated.
Subjecting an electronic resistor to higher voltage levels could result in its damage.
The maximum working voltage of an electronic resistor is provided in volts.
· Surge Handling
Some electrical circuits experience spikes in voltage when in operation.
There are electronic resistors that are fabricated to handle such surges without damaging the component.
Knowledge of an electronic resistor’s surge handling ability is useful, especially when faced with a supply with regular voltage spikes.
· Temperature Coefficient of Resistance
This parameter relates to the relationship between the resistance value of an electronic resistor in the event of changing temperature.
The resistance value is bound to be affected when the temperature exceeds a certain threshold.
The temperature coefficient of resistance is important in precision applications, where the resistance value is expected to remain unchanged.
It is measured in part per million per degree centigrade (ppm/0C).
Can you Interchange Surface Mounted Resistors with Through-hole Resistors?
Surface mount resistors
Yes, you can. It, however, depends on the application and the resistor values.
To interchange surface mounted resistors with through-hole resistors, they have to be within the same tolerance range.
Additionally, they need to share the same parameter ratings if specific to a unique application.
It is also important to check the connecting leads of where you are replacing the electronic resistor.
Through hole resistors
What are SMD Resistors?
Surface-mounted resistors replace the leads on traditional resistors with contacts.
This allows them to be simply mounted and soldered onto circuit boards.
These electronic transistor types are small and functionally reliable besides their low cost with mass production.
Surface-mounted resistors have found use en masse in the electronics industry.
These transistors have similar general properties to the leaded transistor.
Like leaded transistors, the power rating, tolerance, and temperature coefficient of resistance are important parameters to consider for SMD resistors.
Surface-mounted resistors are made from ceramic compounds that enclose a resistive element. This element is usually a metal film.
Depending on the resistance value required, the size of the film can be adjusted.
When a desired length and thickness has been obtained, the film is coated with several strata.
These layers provide protection from physical and chemical damage.
A ceramic build is then added to the agglomerate with metalized contacts provided for connection to the circuit board.
Sometimes the surface mounted resistors are marked with pertinent information when large enough.
Information could include resistance value, tolerance, and working voltage. The resistors are then loosely packed or made into a roll package.
Surface-mounted resistors have the following benefits that encourage their usage:
- Surface-mounted resistors are so small; they are manufactured with the use of robotics. SMDs are accordingly highly accurate with very narrow tolerance margins.
- SMD resistors are typically very small components.
The size advantage allows these components to find use in applications where limited usage of space is of the essence.
- With small size comes the advantage of less stray inductance. SMD resistors can thus be used in high-frequency applications.
SMDs do, however, have some drawbacks.
A major limitation of the SMD resistor is its lower rating of power dissipation than similar value leaded resistors.
Additionally, replacing SMDs is technically consuming. SMDs have contacts attached to their surface and are soldered to the circuit board.
Are MELF Resistors SMD Resistors?
The metal electrode leadless face (MELF) resistor is similar to the surface-mounted resistor but with higher performance levels.
MELF resistors are cylinder-shaped with metal contacts at both ends.
Their construction provides for better stability, accuracy, and resistance to external elements such as temperature and moisture.
MELF resistors are fashioned on a core made of a compound of aluminum oxide.
The core is then layered with a thin film of metal alloy, which is cut into a helix.
This form of engraving helps in achieving the desired resistance value.
Circular plates of nickel and steel composition are placed at the endpoints for contact purposes.
The MELF resistor is enclosed in a hard non-conductive coating to offer protection from physical, chemical, and electrical sources.
The endplates are connected to tin contacts that offer better solderability.
You find the resistance value for MELF resistors is not easily affected by the temperature changes.
They can also handle transients and pulses better than standard surface-mounted resistors.
However, MELF resistors are costly, resulting in their limited use.
Is a Thermistor a Resistor?
Yes, it is.
A thermistor is a portmanteau of the thermal resistor.
It is an electrical device that varies its resistance level with the temperature changes.
This allows its use in temperature measurement and regulation.
Thermistors can be categorized into various forms. They can be categorized according to their functionality and according to their composition.
According to their composition, thermistors can be categorized into metallic based and semiconductor-based.
Thermistors made from metallic compounds are used for high-temperature applications.
Low-temperature applications utilize while semiconductor-based thermistors.
Thermistors can be categorized into negative or positive temperature coefficient thermistors in relation to how they respond to temperature changes.
A negative temperature coefficient (NTC) thermistor has a reducing resistance value with a temperature rise.
A positive temperature coefficient (PTC) thermistor has an increasing resistance value with temperature rise.
NTC Thermistor vs PTC Thermistor
Negative temperature coefficient (NTC) thermistors are used in thermometer used to measure temperatures that are very low.
They are used in thermostats and to control operating battery pack temperatures.
Additionally, they are used to limit in-rush current in circuits supplying power.
Positive temperature coefficient (PTC) thermistors find use in circuits to regulate current flow, much like fuses.
They can be used in determining temperatures on their own or in combination with other devices.
How does a Varistor Work?
A varistor is a special type of electronic resistor used to protect circuits with tendencies to experience surges in voltage and impulses.
They do this by transferring excessive energy created by the spikes and impulses to the ground. With varistors, the voltage applied determines the level of resistance.
Most varistors are made from metal oxides or ceramic compounds.
To protect electrical circuits from voltage spikes, they are usually connected across lines or to the ground wire.
They conduct reduced current when the circuit experiences normal charge flow.
However, they absorb excess current when there is a surge that causes a voltage rise above the threshold value.
Varistors cannot handle continuous surges with a limited power rating.
Consequently, when a surge causes power dissipation beyond the provided rating, the varistor could burn out.
Additionally, their effectiveness wears off over time.
As surge protectors, varistors are useful in making power adaptors and power supply components.
They are also employed in electronics and in devices such as guards for refrigerators and televisions.
In short, you should consider everything mentioned in this guide to get a reliable electronic resistor.
However, in case you have additional questions, feel free to contact Rantle team.