Today circuits have great importance in our lives due to their benefits and features. A circuit comprises different components, and due to this reason, their testing becomes highly important. Therefore testing the parts of a circuit can be done in different ways.
However, you should always opt for the appropriate method. When we test PCBs or other types of circuits, we come to know about their current state and real-time defects.
Testing a circuit needs practice. For the method, we need to get our hands on the specific equipment so that we can drive accurate results from these tests. There are also PCB testing tools like an ohmmeter, a multimeter, and a capacitance meter available that make this inspection feasible for us. We are going to take an extensive look at the testing of circuits and their components in this post.
Stay tuned to find out more and clear your doubts completely as well.
Resistor testing
If you are considering testing the resistors, then you need to stick to some general guidelines. People often mess up the method, and due to this reason, the results are not accurate. Resistors are important in physics. Therefore these are important to test to ensure their fine performance. The resistors have basically two terminals, and their purpose is to resist the current from flowing through a system. We can easily rely on the resistors in special cases. If you want to reduce the chances of current overflow, resistors can help. You will find a huge range of resistors in the market. These differ in pricing and structures. Therefore their potential is different as well. We are going to see how we can test a resistor by using different methods. Let’s get started!
Method 1:
Visual Inspection
The first method for resistor testing is Visual inspection. You can check the circuits and resistors manually through visual inspection. However, this does not guarantee to point out all the possible defects in the resistors. Check the structure of the resistor. Look for burns, scratches, or if a component has been chipped off.
Look for cracks among the components. Also, see if the components are loosely attached to it. Also, sometimes peculiar color changes of the resistor can indicate problems. If you have extensive knowledge of resistors, a visual inspection can help you with this purpose. However, there are higher chances that VI will not provide positive results in all cases. If a visual inspection does not prove to be handy, you can rely on multimeter testing.
Method 2:
Using a multimeter
The role of a multimeter is to measure the current, voltage, resistance, and capacitance of a circuit. Therefore you can use it for different measurements. A multimeter will fully test your resistor by giving you accurate readings. Other than this, you need to know how you can use this multimeter for testing your resistor. Before you proceed further, you need to set it to resistor mode. After this, connect its probes to the resistor. Take the reading. If you check the color code of your resistors, it will help you determine the accurate reading. Now compare the given reading with the resistor’s color code.
If the reading matches the tolerance, then there is nothing wrong with your resistor. In case it does not match, then the resistors are definitely defective. A multimeter only works for individual resistors. You cannot test the resistors attached to an existing circuit. Therefore make sure of this in order to get the precise results. In case you have an in-circuit resistor, then detaching it from the setup will be a good option. Once you have tested it, you can go for re-soldering it later. If you find using a multimeter not suitable, then there is another option of using a component tester for inspecting the resistors.
Method 3:
Component tester
You might find component testing much more interesting than other inspecting methods. What you need to do is that use a component tester and switch it on. After this, place the resistor in its socket. Now push the test button.
The tester will display the reading at once. A component tester displays the reading if there is nothing wrong with your tester and displays “bad” if it’s defective. This is, again, only reliable for the individual resistors. This method is not only quick and easy to use, but you get the results promptly as well.
Capacitor testing
If you are into physics, then you would know capacitors really well. A capacitor is an electrical component in the devices, and its role is to store energy. Normally, we learn about two basic types of capacitors. One is the electrolytic capacitors, and the other is ceramic capacitors. There is no role of polarity in the performance of ceramic capacitors.
Ceramic capacitors also give you enough room while testing because you don’t have to follow their individual terminals during connection. There are different methods that allow us to test a capacitor. Let’s check them out below:
Method 1:
Visual inspection
Just like resistor testing, you can test a capacitor through visual inspection. Basically, visual inspection is a common testing method, and experts recommend following it before proceeding with the other techniques. When following VI for capacitor testing, you need to check and identify the structural defects in the capacitor. Also, check the upper side of the capacitor and see if it’s damaged or not. You also need to check for cracks and leakages. It is because these can lead to electrical fires and short circuits later.
You can also look for bumps and dents in the capacitor’s body. Here’s a fun fact: We assemble capacitors at the front of most of the electronics because they are good at noise-filtering the device. Capacitors are also beneficial in terms of receiving smooth signals and avoiding distortion. There is no doubt that the function of capacitors is intensive, and there are higher chances that these can undergo defects. Therefore VI is a great method to see their real-time issues. In most cases, the capacitors present at the front of the devices are more likely to undergo damage and faults.
Method 2:
Multimeter
As we have talked about it earlier, a multimeter is a good testing tool for off-circuit capacitors. In case you want to test in circuit capacitors, then desoldering them would be reliable. In both cases, you need to follow a proper process for inspection. Or else you will not receive the desired results at all. When we are using a multimeter for testing the individual capacitors, then we need to switch the multimeter to the capacitor mode.
Connect the black probe of the multimer to the negative side while the red probe goes with the positive side. Now you will find a default value of the capacitor mentioned on its structure. You will compare the multimeter’s reading with that value. If the values are alike, then the capacitor is fine. If not, then the capacitor is defective.
Diode testing
Diodes are important for the routing of the flow of the current. So that the current only follows a single direction throughout the system. Diodes are also good for power supply to the devices. It comprises two terminals and allows the current in a single direction when we have successfully established a forward bias condition. Diodes are important in physics because they are energy-efficient and switch between conditions quite promptly. Therefore, these save time and power at the same time. We can also test diodes through different methods. The details are below:
Method 1:
Visual inspection
We can start with VI, just like for a resistor and a capacitor. The purpose is to manually check the diode for defects and problems. It can be anything, broken wiring, damaged structure, dents, cracks, and leakage. Some diodes indicate problems through color changes. It means you need to consider an immediate replacement and discard this defective diode as well. Sometimes the terminals of a diode also undergo damage, and their color changes to black. If the diode is heating up often, then it signals a problem.
There are still some problems that can be missed out through visual inspection. It is because when we manually do something, there are chances of human error. In this case, experts recommend using a multimeter. It is a digital diode testing device and leaves no room for error. Therefore relying on a multimeter for diode testing will prove to be effective in this regard.
Method 2:
Multimeter
By far, you would have a general idea of using a multimeter for diode testing. Get a multimeter and set it to diode mode. After this, connect the probes of the multimeter with the diode and check it. The reading will give you an idea of the state of the diode.
Now you need to switch the probes and re-connect them to get the final and accurate results. Using a multimeter is handy and quick. Plus, it delivers precise results without making you struggle for accurate readings.
LED testing
LEDs are nothing but a sort of diode used in different devices. There should be different appliances in your home that have an LED attached to them. Did you know that we can test these LEDs as well? LEDs are diodes, and therefore, these have two terminals. Besides, LEDs are available in different shapes and colors, and you can choose from a wide range of sizes as well. LEDs work with power and glow when we supply power to them.
Circuits that work with LEDs use their colors to indicate different phases. Therefore when a device is ON, its LED will glow, and in case it’s OFF, its LED will not glow. Similarly, if a device’s battery is low, the LED will glow in a different color showing that the user needs to charge the device.
Transistor testing
Transistors are another important physics component that we use in our home appliances and electronics. Transistors are also a part of the latest and innovative technical devices that we often use in our routine lives. It has three terminals in total, and these are variable as per the incoming signals.
You can identify the defects in a transistor by simply using the VI method. It is because the natural shape, performance, and structural quality of a transistor normally give you a general idea regarding its state. Also, you can use another suitable alternative for testing transistors at your convenience.
Advantages of Component testing
The field of electronics and PCBs both cannot ignore the importance of component testing. It is because a professional PCB producer or an electronics provider deeply understands the significance of component testing for the sake of the safety and quality of circuits and electronics. In this section, we are going to have a look at some of the salient benefits of Component testing for you:
- It enhances the confidence of a producer in its products
- It increases the component quality
- The tested and verified products meet industrial standards
- The inspected products are more reliable
- The component testing makes the components safe to use at home
- The tested components are also durable and show perfect quality
Conclusion
Electrical components inspection is highly important if we want to produce industrial-grade devices. Any small defect in the abovementioned and other components can incur a big loss not only to users but also tarnishes the reputation of the producers. Therefore, before delivering them, a producer has to make sure that all the components are working fine and are in a perfect state to serve longer.
Testing comes in handy because it saves us from loss of investment. Plus, our devices remain protected from potential damage at the same time. There is no doubt that some testing methods are highly expensive, and high-end producers can think of using them only. However, with a little research, we can learn about affordable alternatives easily.