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How to Check SCR Using Multimeter

Written By

Enrique

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A multimeter is a handy tool to have in any electronics workshop and can be used to check the electrical values of circuits. This blog post will show you how to check scr using multimeter. This is a common test for checking the health of a Schottky diode and will help you determine if it needs to be replaced. Let’s get started!

How to Check Scr Using Multimeter

What Causes an SCR to Fail?

There are a few reasons why an SCR may fail. The most common reason is due to age and wear. Over time, the components in an SCR can degrade and stop working correctly. This is especially true if the SCR is used in a high-powered circuit. Another common reason for failure is physical damage. If an SCR is dropped or hit, it can break and stop working. Additionally, SCRs can also fail if they are overloaded.

This can happen if too much current is trying to flow through the SCR. The other main reason why an SCR can fail is due to a manufacturing defect. In some cases, the components in an SCR may not be of the highest quality and can fail prematurely. Lastly, SCRs can also be damaged by excessive heat. If an SCR gets too hot, it can start to degrade and eventually fail.

Why It’s Important to Test Your SCR

SCRs are important components in a variety of electronic devices. If an SCR fails, it can cause the device to stop working correctly or even fail entirely. For this reason, it’s important to test your SCR regularly to ensure that it is still functioning properly. Another reason to test your SCR is to verify its values. Over time, the values of an SCR can change due to age or wear. By testing the SCR, you can ensure that it still has the correct values. Finally, testing your SCR can also help you diagnose other problems in a circuit. If an SCR is not working correctly, it can cause other components in the circuit to malfunction.

Step by Step How to Check Scr Using Multimeter

1. Gather the Necessary Equipment

The first step is to gather the necessary equipment. For this test, you will need a multimeter, an SCR, and a power supply. Gather these items and have them ready before proceeding to the next step. If you don’t have a power supply, you can use a 9V battery. Try to use a fresh battery for the best results. Avoid using a power supply that is too weak or too strong for the SCR.

You Can Use a 9V Battery

2. Set Up the Multimeter

Next, you will need to set up the multimeter. For this test, you must set the multimeter to measure DC voltage. Most multimeters have a separate setting for measuring DC and AC voltage. To set the multimeter to the correct settings, first, make sure that the multimeter is turned off. Then, find the DC voltage setting and set the multimeter to this setting. Once the multimeter is set to the correct setting, you can turn it on. If you’re unsure how to set the multimeter to measure DC voltage, consult the user manual.

3. Set Up the SCR

After setting up the multimeter, you will need to set up the SCR. To do this, you will need to connect the SCR to the power supply. Make sure that the polarity is correct. The Cathode of the SCR should be connected to the positive terminal of the power supply, and the anode should be connected to the negative terminal. Once the SCR is properly connected, you can proceed to the next step.

4. Connect the Multimeter to the SCR

The next step is to connect the multimeter to the SCR. To do this, you will need to touch the probes of the multimeter to the correct terminals of the SCR. The red probe should be touching the Cathode, and the black probe should be touching the anode. If the probes are touching the wrong terminals, the multimeter will not work correctly. Try to avoid touching the SCR with your bare hands, as this can cause static discharge.

5. Test the Forward Voltage Drop

Once the multimeter is connected to the SCR, you can begin the test. The first step is to test the forward voltage drop. To do this, you will need to apply a forward current to the SCR. The best way to do this is to use a power supply. Set the power supply to a low voltage and then apply the current. You can also use a 9V battery for this test. First, make sure that the multimeter is set to measure DC voltage.

Set the Power Supply to a Low Voltage

Then, touch the probes of the multimeter to the correct terminals of the SCR. The red probe should be touching the Cathode, and the black probe should be touching the anode. Once the multimeter is connected, turn on the power supply or battery. The multimeter will register the voltage drop across the SCR. This value is known as the forward voltage drop.

The forward voltage drop should be within the range specified by the manufacturer. If it is not, then the SCR is most likely defective.

6. Test the Reverse Voltage Drop

The next step is to test the reverse voltage drop. This test is similar to the forward voltage drop test. However, instead of applying a forward current, you will be applying a reverse current. To do this, you will need to use a multimeter that can measure DC current. First, set the multimeter to the DC current setting.

Next, connect the positive lead of the multimeter to the anode of the SCR and the negative lead of the multimeter to the Cathode of the SCR. Finally, apply a reverse current to the SCR. The multimeter should read a small voltage drop across the SCR. If the voltage drop is too large, then this indicates that the SCR is damaged and needs to be replaced.

7. Test the Gate Trigger Voltage

The next step is to test the gate trigger voltage. The gate trigger voltage is the voltage that is required to turn on the SCR. To test the gate trigger voltage, first, connect the multimeter’s positive lead to the SCR’s gate terminal. Then, connect the multimeter’s negative lead to the cathode terminal of the SCR. Finally, slowly increase the voltage on the anode terminal of the SCR until the LED on the multimeter lights up.

The voltage at which the LED lights up is the gate trigger voltage. If the gate trigger voltage is too low, the SCR will not turn on. The SCR will be damaged if the gate trigger voltage is too high.

SCR Will Be Damaged

8. Test the Holding Current

The next step is to test the holding current. The holding current is the minimum current that is required to keep the SCR conducting. If the current falls below the holding current, the SCR will turn off. To test the holding current, first, disconnect the anode from the load and connect it to the positive terminal of the power supply.

Then, connect the Cathode to the negative terminal of the power supply and slowly increase the current until the SCR turns on. Once it turns on, you can increase the current until it reaches the desired value. The holding current is usually between 1 mA and 100 mA.

9. Test the Leakage Current

The final step is to test the leakage current. The leakage current is the current that flows through the SCR when it is turned off. To test the leakage current, connect the multimeter to the SCR so that it measures the current flowing through the SCR. Then, turn off the power to the SCR. The leakage current should be less than 1mA. If the leakage current is greater than 1mA, the SCR is defective and should be replaced. Testing the leakage current is a quick and easy way to check if an SCR is working properly.

10. Record Your Results

Once you have completed all the tests, recording your results is important. This will help you track which SCRs are working properly and which are not. First, make a note of the forward voltage drop, reverse voltage drop, gate trigger voltage, and holding current. Then, make a note of whether or not the SCR passed each test. Finally, make a note of any other observations that you made during the tests. Try to be as detailed as possible.

You Can Check It Out To Check Neutral With Multimeter

Scrs Are Working Properly

Conclusion

So now you know how to check scr using multimeter. Follow the steps in this article, and you should be able to test any SCR. With a little practice, you will be able to quickly and easily troubleshoot any problems that you may have with your SCR. We hope that you found this article helpful. Thank you for reading!

You Can Check It Out To Check a Ballast With a Digital Multimeter

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