Are you a beginner designer? Then we bet you know how crucial capacitor symbols on a multimeter are! However, identifying them and cracking their meaning is another difficult task. But, with PCBasic, we've made it easy for you. Whether you're working on a circuit design or simply just want to interpret a capacitor schematic, we've jotted down some important capacitor symbols below, explaining their variations and their examples used in different systems. So, without any further ado, let's have a look.

What are Capacitors?

Capacitors are the base of any circuit. Without them, you're at the loss of your design since they simply won't work. Basically, they store and release energy in a circuit. Moreover, they are also called passive components in the circuit. Why? Because they generate electrical signals without you putting any additional effort on them.

However, there's one drawback of the capacitors. As you know, they are passive components, so they only store, dissipate, and release energy but cannot create or control the flow of electricity. Although it's a setback, it has a lot to offer.

What are Capacitor Symbols?

Capacitor symbols are just like a graphical representation or a logo you see in daily life. As an engineer or technician, these symbols come in handy as you can identify the components in a design without looking at the physical layout of the circuit.

Now you must be wondering why capacitors are here in the first place? It is due to their ability to temporarily hold charge that makes it useful for stabilizing power supplies. You can find them in different forms:

·   Ceramic

·   Electrolytic

·   tantalum

But why does accurate symbol representation matter? Because it helps both circuit design and troubleshooting. Not only this, when you interpret the symbols correctly, you're saving yourself a lot of time and energy. Let's take an example of troubleshooting. When you correctly read these symbols, you know where the issue is and can easily correct them.

But what if you end up identifying the capacitor symbols on the multimeter incorrectly? In that case, it might turn into a nightmare. You wouldn't know where the issue is. This all would end up in costly errors, delayed projects, or even damage to sensitive equipment. We're sure you wouldn't want to end up like this. So, head on to the sections below to understand what different symbols look like.

Importance of Understanding Capacitor Symbol

Understanding capacitor symbols is important as they indicate where capacitors are used and exactly which type they are. But, there's more to the tale. Let's find out how capacitor symbols in a circuit can help you out.

·   At the start, you can quickly select the right type of capacitor that will help you in tasks like filtering, coupling, or energy storage.

·   You would know the correct placement of components.

·   Instead of physically examining every component, you can analyze the schematic to spot any issue.

·   It helps you to effectively communicate with your team members to brief the project.

Types of Capacitor Symbols

Let’s have a breakdown of different capacitor symbols you would encounter as a designer.

1.    Polarized Capacitor Symbols

Polarized capacitors are sensitive to polarity. Here you’d find distinct positive (+) and negative (-) terminals. However, there are more sub-branches to it. Let’s have a look.

2.    Non-Polarized Capacitor Symbols

These types of symbols are widespread, as you can see them in almost everything. It is due to their versatility that doesn't require any polarity considerations.

3.    Variable and Trimmer Capacitor Symbols

These symbols are important as they allow for adjustment of capacitance values. This property makes them ideal for fine-tuning circuits such as RF tuning. Let's have a look at some of its examples. 

4.    Specialized Capacitor Symbols

Specialized capacitors are tailored for specific high-performance or application-specific uses. Their symbols often provide extra details about their function. Here are some of its examples. 

Capacitor Symbol in Circuit and on Multimeters

The capacitor symbols you see on both circuits and multimeters are important since they help the designers design, diagnose, and test. In the schematic, these symbols indicate whether the capacitor is polarized or non-polarized.

Now you must be aware of what these symbols we've discussed above look like. For polarized capacitors, like electrolytics, you must connect positive and negative terminals with a detailed eye, while non-polarized ones can be connected in either direction.

How to Test a Capacitor with a Multimeter?

Testing a capacitor with a multimeter can help you determine if the capacitor is functioning properly or if it's faulty. Here at PCBasic, our team tested a capacitor in two ways. One uses the capacitance mode and the other uses the resistance mode. Here's a brief explanation of how we do this.

Testing a Capacitor with Capacitance Mode

As we advance in technology, newer devices have a specific mode for measuring capacitance. If your device also has one, then this is the most straightforward method.

1.   Before testing, we recommend you fully discharge. This step is crucial as a charged capacitor can cause damage to the multimeter or give inaccurate readings.

2.   Next, you need to turn the dial on your multimeter to the capacitance setting.

3.   Then connect the capacitor to the multimeter. At this point, you need to be extra careful about the type of capacitor. For polarized capacitors, connecting positive (red) leads to positive terminals and negative (black) leads to negative terminals. For non-polarized ones, orientation doesn't matter.

4.   Then you'll observe capacitance values in farads (F), usually in microfarads (µF), nanofarads (nF), or picofarads (pF).

5.   Compare the value you see to the value printed on the capacitor.

6.   If the reading is significantly lower, zero, or shows "OL" (overload), your capacitor is likely faulty.

Testing a Capacitor with Resistance Mode (Ohmmeter)

If your multimeter doesn't have a capacitance function, you can still check the capacitor's functionality using the resistance mode.

1.   Discharge the capacitor before testing, following the same method as above.

2.   Turn the multimeter dial to the resistance setting (Ω). For large capacitors, select a higher resistance range like 2MΩ (megaohms).

3.   Connect the multimeter leads the same way with capacitance mode.

4.   Observe the resistance reading. If it starts slowly and gradually increases until it stabilizes. It's a good sign as it indicates your capacitor is fully charged.

5.   If the resistance becomes zero it means that you have an open circuit and it cannot hold charge.

6.   If the resistance stays close to zero, it means the capacitor is shorted internally and is no longer functional.

7.   After completing the first reading, we recommend you reverse the multimeter probes. Reversing the leads is particularly important for electrolytic capacitors because it helps confirm that the dielectric layer is intact and charging properly in both directions.

Conclusion

Understanding capacitor symbols is important as a designer as it helps you to interpret your circuit design. Moreover, different types of capacitors have unique characteristics which you must know to correctly troubleshoot the design. From basic to non-polarized capacitor symbols, you must select the appropriate component for specific applications. For instance, if you have a high-capacitance project, then we would recommend you use a multi-ceramic capacitor.

FAQs

Why Different Capacitors Have Different Symbols?

It is because they represent specific functions they perform in a circuit. It will help you to quickly gauge not only the capacitor's general function but also its type, behavior, and sometimes even polarity.

Can Different Capacitors Be Interchanged?

No, different capacitors cannot be interchanged because each type is designed for specific electrical properties and applications. However, you can interchange between their subtypes. For instance, non-polarized capacitors can be interchanged with each other for signal filtering, coupling, and decoupling purposes. Moreover, we would not recommend you interchange them as they can affect circuit performance, especially in high-frequency applications.

How to Identify Polarized, Non-Polarized Capacitors from Symbols?

You can easily identify polarized and non-polarized capacitors just by looking at their schematics. For instance, you will see a positive sign with two parallel lines in polarized capacitors. As far as non-polarized capacitors are concerned, they only have two straight parallel lines with no marking for polarity.