If you’re keen into electronics, then you may have an idea that testing electronic components is an important part whether you are repairing devices, troubleshooting or constructing circuits. Different electronic elements have their individual purpose and the way they are tested. In this article, we will consider in detail the way to perform the testing of the following components: resistors, capacitors, diodes, transistors, and integrated circuits (ICs). Conducting proper tests on your components enables you to ascertain that they are performing efficiently and also minimize the replacements made on the components.
Begin With The Right Instruments
You cannot begin to test electronic components without the necessary tools. Among the various tools required to test continuity, voltage, current, resistance, a multimeter stands out as the most important. If you have a multimeter, then it is possible to test for continuity in various components such as resistors, capacitors, and even diodes. More complex components may require the use of additional equipment such as an oscilloscope however for the most part, ordinary components need no more than a multimeter. It may ensure easy diagnosis of your troubles and all measurements you make are accurate so long as you have the right instruments.
Testing Resistors
Starting with one of the simplest, we have the resistors. In a circuit, they are meant to oppose the current flow. To test a resistor, place a multimeter set to resistance across each end of the resistor gauge. If an expected level of resistance is noted by the multimeter, it means that the resistor is still functional. This, however, has a limit, and should the multimeter only read infinite resistance, it tells the user that the resistor is burnt out and needs replacement. On the other hand, zero resistance, or something near, indicates that the resistor is shorted and should also be replaced. When measuring the resistance of the component, it is necessary to verify that the measured value corresponds to the rated value, which is most often indicated by the color code of the resistor.
Examining Capacitors
Capacitors are electrical components that help to store the energy for later use. Testing the performance of a capacitor can be a little more challenging as compared to that of a resistor. For instance, it is important to establish whether the device under use has a capacitance setting up on the multimeter. The next thing to do is, Attach the capacitor leads to the multimeter and read the values registered on it. If the value obtained is dramatically lower when compared to the value rated on the capacitor, then chances are that the capacitor is faulty. Another way for checking the condition of a capacitor is to measure resistance; together – pass the probes to either side of the capacitor, and see whether the resistance does not move too slowly upward. If one sees a sudden shift of resistance, then this indicates that the capacitor is faulty, and that leakage is present. These components should also be visually examined for any bulges, leakage or discoloration, as they would have been ruptured.
Testing Diodes
Because diodes permit current to flow through them in only one direction, they are essential in circuits that change AC to DC current, for instance in power supplies. To perform a diode test, change the settings of the multimeter to the diode mode. Now, put the probes onto the terminals of the diode. A workable diode has a forward drop of roughly 0.6 to 0.7 volts (for silicon diodes) when the positive probe is on the anode and negative test lead is on the cathode. If such is not the case, the diode must not work because the voltage drop does not show changes. Reverse the probes to test the diode’s reverse bias. A working diode should not show continuity in this direction. In this case, if the multimeter shows continuity in reverse, the diode is shorted.
Testing Transistors
It is safe to state that transistors serve two important roles, they increase the amplitude of an electrical signal, and they are used as electronic switches. In testing the transistor, the procedures the voltage drops across the base-emitter and base-collector junctions respectively. Switch your multimeter to diode mode and proceed to test the junctions of the transistor one by one. Connect the positive probe to the base and the negative to the emitter. A healthy transistor will demonstrate a function, which should be a voltage drop of between 0.6 to 0.7 volts. Do the same between the base and collector. If the multimeter measures the electrical conduction on both junctions correctly, then the transistor is very likely ok. If there is now such a reading or the readings are not accurate then the transistor cannot be relied upon. Ensure you check all three junctions of the transistor to have a full evaluation.
Testing Integrated Circuits (ICs)
Testing of integrated circuits is quite intricate in that an integrated circuit is composed of many transistors, diodes and resistors which are integrated onto a single chip unlike testing a single component for example a resistor or a diode. In order to test the integrated circuit, it is firstly necessary to verify that power has been supplied to the integrated circuit. An alternative IC verification might be simply to use the multimeter. This involves measuring the power voltage supply at the power pins of the integrated circuit, pin checking and making sure the required supply voltage is provided. Circuits can then be verified for shorts or cut currents or open circuits. For further developments that required thorough testing, threshold limiting switches could be used. This required the use of an IC that contains measuring devices like oscilloscopes. An oscilloscope can be used to check the voltage level of signals supplied to the ICoutput. It is sometimes necessary to check with the oscilloscope what shape the operating signals have in the time space and how the IC functions. Without such devices, it would be necessary to simply check the appearance of the integrated circuit or simply check the pressure supplied to it in order to find possible problems.
Testing Inductors
Components that are categorized as inductors are used to store energy in the form of a magnetic field and they are mostly found in power supplies and signal processing circuits. Switch the multimeter’s dial to the resistance mode in order to measure an inductor. Use the test probes placed across the leads of the inductor and test for continuity. A good inductor will show low resistance, while a faulty one may show no continuity at all. If the wound inductor is rated or designed for a certain inductance’s value, depending on the design and structure of the inductor one may also measure the impedance of the inductor by using a multimeter with an inductance feature. In the case when the difference between the rated inductance value and the impedance value deviates too much the conclusion of the inductor being faulty is drawn.
General Tips for Testing Components
The first step of the Capacitors, Resistors and Inductance tester method is to ensure that the circuit gets assembled correctly. When testing electronic components the first thing which has to be kept in mind is that when you turn off the switch, you Delete all the power supply given to your circuit. Always avoid assuming the functionality of a component unless and until you know about it. To settle any formality, datasheets provide administrative and testing information regarding any electronic component which has to be kept in hand. Before going for the tests and attaching multimeter leads to any of the components, take a good look at the component to note any signature or features like cracks or burnt marks which would indicate that the part is defective. Such features if present are a strong physical problem and chances are high that the component is faulty, so do not waste time!
Conclusion
One of the most intimidating situations when engaging with electronics is when someone mentions testing out a complex component or ‘unit’ as they like to call them. But worry not, be confident in your capabilities as these components can easily be tested out, and make quicker repairs/restorations. When working on arcs, for example, resisters, capacitors, diodes, transistors, or circuits and feel confident about your multimeters, be sure to apply the Circuit Theory. Structure the conquered components into a single box or ‘suitcase’, flip it, and you will automatically feel yourself to be in total control. The magical desire to control is ideal. If you are not blurry on the core concepts revolving around the necessity of doing such component tests, as well as keeping yourself indulged in practical work, such electronics will turn out to be much easier for you to simply comprehend.
