If you’re looking to figure out whether the resistors like thermistors have any polarity, then don’t worry; you are not alone. We’ll be going through the basics of thermistors, capacitors, and diodes here.
So, if your question is, “Do Thermistors Have a Polarity Like Capacitors and Diodes?” you will find the answer soon enough. This discussion will include the subtle differences among thermistors, capacitors, and diodes.
By the end of the articles, you’ll be aware of the different characteristics of the three different components. You will also be able to find out whether they have polarity or not.
So, if you are trying to learn the basics, you will also be enlightened by this article. Let’s dive into it!
What Is a Thermistor?
Let’s talk about what thermistors are, and then we will be moving onto how they work. You might be thinking that the word “thermistor” is a combination of a couple of words. Well, you would be correct.
It is actually formed from a combination of the words resistor and thermal. If you think about these two words together, you probably can guess that the component has something to do with temperature and resistance.
Correct, again! The resistance of thermistors depends on the temperature. So you can basically consider it a resistance thermometer. And just like many other types of thermometers, they have a familiar construction.
It means you might be able to see the metallic oxide from the outside. The outside covering is made from glass or epoxy in most cases. And the entire component is formed into a cylinder or a bead.
Although these devices aren’t perfect for the most extreme temperatures, if you’re trying to measure the temperature at a certain point, these will be your go-to components.
Physicists still use these because they’re comparatively cheap, and you can rely on them to be durable. They’re also quite simple to use.
You might have already seen thermistors around you because they’re pretty common. The most common case would be their use in digital thermometers. You can also see mechanics use them to check coolant and oil temperatures.
Even in our common home appliances, you can see them in abundance. Especially in refrigerators and ovens, you can observe them since they need protection from cooling and heating. So, the thermistors can provide safe operation.
You can observe a more scientific use of thermistors when detecting laser stabilization. Other laboratory devices include charge-coupled devices and optical blocks. Usually, a ten kΩ is enough for stabilization detecting.
Types of Thermistors
You can actually find a couple of types of thermistors locally. They are more commonly known and the NTC thermistors and the PTC thermistors. Both types have their specific uses.
If you are trying to figure out which one is more common, let me cut to the chase. NTCs or the negative temperature coefficient thermistors are more common than PTCs. If the surrounding temperature decreases, an NTC thermistor would note a decrease in resistance, vice versa.
So you can probably guess the characteristic of PTC thermistors. That’s right! With an increase in temperature, you can observe an increase in resistance to the rise of temperature. Read details here…
How Do They Work?
Now that you know what they are and where they are used let’s move on to their operations. Well, there are a couple of types of thermistors, as we have already discussed.
The material used inside a thermistor decides the change in resistance with the change of temperature. They are pretty nonlinear, which means you will not get a straight line if you try to identify a relation between resistance and temperature.
What the graph will show is actually a curve. So you can observe how much the line changes. It would usually depend on how the thermistor is constructed.
Advantages of Using Thermistors
So, what sets thermistors apart from other sensors? Well, there are actually a few benefits you might get from using a thermistor. These thermistors are quite sensitive and durable.
You can also expect them to be comparatively smaller and more affordable. So you can actually buy them in bulk for your crazy experiments. If you’re only looking to measure a single point temperature, then these little devices are recommended.
Thermistors in a Controlled System
So, how do these little guys operate in a controlled system? Well, the process is quite simple, actually. You will observe a small bias current running through the thermistor.
A certain temperature controller sends this current. Since the controller can not recognize resistance, it has to convert it into a change in voltage.
You have to place the thermistors close to the devices to guarantee accuracy. The thermister can either be embedded into the temperature control device or simply attach to the device.
This is the problem with thermistors. You will not get accurate readings if you place them away from the temperature control device.
Do They Have a Polarity?
Now it is time to get into the good part. This is what you’ve all been waiting for. Well, what is the straightforward answer? Thermistors have no polarity. They are definitely resistive but not polar.
So, if you were expecting them to be similar to diodes and capacitors, this definitely proves that they are not. You can find thermistors at different resistances and with some other characteristics.
You can use thermistors as temperature sensors in various temperature control circuits. They can also control the temperature with the help of a bridge along with measuring temperature.
These little devices are more similar to resistors than capacitors or diodes. They change the readings depending on the surrounding temperature.
So if your question was, “Do thermistors have a polarity like capacitors and diodes?” then you’ve got your answer. These devices act similar to resistors instead of diodes or capacitors. So you can’t expect them to have polar characteristics.
If you want polarity and polar characteristics from these electronic devices, you should stick with capacitors and diodes.