How to Test a Capacitor?

This article is all about, What is a Capacitor?, How to Test a Capacitor? , Where it’s mostly used? , How to discharge a Capacitor?. If you read the article with full concentration then you’ll be able to understand all the given topics in this article. ????

WHAT IS A CAPACITOR?

It’s an electrical or electronic instrument that stores energy in the form of an Electronic charge. Its mostly used in electronic circuit boards, electronic appliances as it performs a lot of functions.

Outline

[lwptoc colorScheme=”dark”]

Why do we need to test a capacitor?

Its rule of buying, if you buy any appliance it’s tested is must check whether its working or not. Some of the methods for testing Capacitor are given below;
1: In an active current flowing circuit when it is placed, the charge starts to build upon one of the plates inside it. Once it starts rejecting more charges then it means that the Capacitor is fully charged.
2: The discharging of the capacitor can be explained in such a way that when the circuit demands back its charge just like the bypassing it, then it releases the chargeback to the circuit and it’s continued until the circuit stops demanding or the charge is completely released.

CLASSIFICATION of capacitor:

Literally, it can be divided into 2 types.
Electrolytic and non-Electrolytic. It can be easily damaged by the voltage signs permanently, just like other electronic appliances.
The Capacitor that often gets damaged and releases more current in a minimum period of time or those which can’t hold current due to overtime are known as Electrolytic.  On the other hand Capacitor, that’s leaks all its charge is known as Non- Electrolytic.
There are numerous numbers of Methods to check the capacity of capacitors. Some of these methods are listed in this article.

NOTE:

Some of the best ways to check a Capacitor are mentioned and we had added it just to show the possibilities and to increase the knowledge of a reader.

How it can be Discharged?

The word discharge means “not having the ability to store current or charge. On the other side, it is an electronic device used for the storage of energy. So now it’s important to understand how properly it can be a Discharge. It’s very important because it is constructed in such a way that if the current is disconnected it can still hold a current. It can give a person an electric shock if it’s not fully discharged and a person’s hand unconsciously touches the lead of it then it will discharge through the human body.

Using a Screwdriver:

Warnings:  The beginner should not use this method as it will generate current sparks will discharging, which might cause damage or the person might get hurt.
At first, disconnect it from a circuit carefully then don’t touch its terminals. Then take a screwdriver with a long rubber or wooden handle and hold it in one hand, then take the Capacitor on the other hand and connect the metal part of the Screwdriver to its terminals.
Then electric discharge will take place and you will hear the crackling and see the current sparks. It shows the electric discharge.  Do it a couple more times and make sure it’s is fully discharged.

Using a Discharge Resistor (Bleeder Resistor)

This one is the safest way of discharging. It’s commonly used in power supplies and in circuits where Bleeder Resistor is placed parallel to the output. When the current is disconnected, the remaining charge in it is released through the resistor.

FOR EXAMPLE:

Make a circuit by putting a large value Resistor (few kilo Ohms ) with a current rating of up to 5W and then connect it with the terminals. Use wires with crocodile clips on either side instead of using direct wires. Then the flow of discharging will slow down or decreases and the voltage reading on both terminals will be easily noted while using a Multimeter.
For example, consider you have a 1000µF  eligible for 50V and you want to experiment with discharging to 1V,  using a 1KΩ Resistor, it will take almost 4 seconds to discharge the capacitor. Also, the power rating of the resistor will be at least 2.5W.
NOTE:
High Power Supplies Resistors are mostly expensive as compare to normal Resistors of 1/4 Watt or 1/2Watt.

Method 1 Checking a Capacitor using Multimeter with Capacitance Setting

In this method, a Multimeter is used to check the capacity. It’s one of the easiest, fastest, and best methods to check a Capacitor. For this method, a digital Multimeter with Capacitance of mid and high end is mostly used.
 Mostly, Multimeter displays the capacity but there are few Multimeters that show other things like ESR, leaking, etc

STEPS:

  • At first, separate it from the circuit and discharge it completely. Note the visible value usually its Capacitance is in microfarads.
  • Secondly, For measuring capacity set a knob on the Digital. Now connect the Multimeter probes to the terminals. If it’s polarized, connect the black clip with the negative terminals and the red clip with the positive terminals.  For making it easy there must be a sign given on either side.  In a Non-polarized one connect it according to your own choice as it doesn’t have polarity.
  • On the third step, note the reading of the Digital Multimeter, if the noted rating is closer to the actual value given on the Capacitor then it’s considered to be a good one.
  • Last but not least, if there is a lot of difference between given and noted values then return it, it is a dead one.

NOTE :

If you wanna measure Capacitor capacity from nano farad to a few hundred microfarads, then use this method. The capacitance range in the above-given values can be measured easily.

 

"Checking

Method 2 Checking a Capacitor using Multimeter without Capacitance Setting

All Digital Multimeters have the ability to check the capacity except those of low and cheap quality, as they don’t have such features but still, we can use it in testing.

Steps:

• The First Step, of all methods is the removal from the circuit and making sure it’s fully discharged.
• The Second step includes, making a proper setup for measuring the resistance through Multimeter i.e. set the knobs to the given resistance setting. In the case of multiple ranges of resistance Measurement, always select the higher range one which is between 20 KΩ to 200 KΩ).
• In the third step, if it is a polarized one then connect the black crocodile clip to the negative terminals and the red crocodile clip to the positive terminals.
• In the fourth step, Note down the value of  Capacitance that was visible for a short period of time, the Multimeter will display the value of Resistance and it will also display the resistance of an open circuit as well. Then remove it from the Multimeter and repeat it few times.

 Conclusion of steps:

By repeating the process again and again, it must show the same result each time to make it a good Capacitor. No change in the resistance of further results shows the Capacitor is used useless or dead.
This method for checking the Capacitance can’t be correct but it can clearly separate the good and bad Capacitors.

"Checking

Method 3 Testing it by measuring the Time Constant:

Another method for checking whether the Capacitor is a good one or the dead one is by measuring the Time Constant Method. This method will work if the value of the Capacitance is given or known. When the given value and actuarial value of the Capacitor are similar then it can be said that the Capacitor is the best one.

NOTE:

In this method, an Oscilloscope should be used instead of a Multimeter because it’s the best one.
Here a question arises what is Time Constant?
It is a charging time taken by a Capacitor to charge its plates up to 63.2% from the supplied voltage through the known resistor. For measuring Time Constant, Capacitance and resistor are must and for deriving its formula symbols are used. Some of these Symbols are given below;
• For Capacitance (C)
• For  Resistor (R)
• For Time Constant TC or Tau – τ is used.
• Formula is = τ = RC

STEPS:

  • First of all, cut the voltage or power supply to the Capacitor for disconnecting it from the circuit and carefully discharge it.
  • In the Second Step, Connect the Capacitor with a known resistor whose value is typically 10 KΩ. Then Allow the power supply carefully with known voltage After completing the circuit.
  • In The Third Step, Note the Time taken by the Capacitor to charge its plates up to 63.2% from the power supply or supplied voltage, i.e. For Charging up to 63.2% a Capacitor needs up to 7.6V if the supplied voltage is 12V.
From the above example, it’s clear that the Capacitance of a Capacitor is measured by the mentioned Time and Resistance with the values which are mentioned on a Capacitor.
The fourth step is usually the conclusion of the above method. The capacitor is known to be best if the noted value and given values of the Capacitor are nearly matching and if the values are different then Capacitor needs to be exchanged.
By using the above method, the discharging time of a Capacitor can also be calculated. Time should be noted down when the discharging value of a Capacitor reaches 36.8% at peak volts.

"Test

 

Method 4 Test a Capacitor with a simple Voltmeter

The capacitor is an electrical device that is constructed in such a way that it can control high voltage. In this method voltage rating is used to check the capability of a Capacitor so later on it can be named good ????or bad????.

STEPS:

The First Step of each method is to disconnect and discharge a Capacitor for safety purposes.
  • In the Second Step, research is conducted on the voltage rating of the Capacitor. The maximum voltage Capacity of a Capacitor is 16V, 25V, 50V, etc. The capacitor can easily control given voltage values.
  • In the third Step, Create a circuit by adding or connecting the battery or power supply but be careful with the voltage supply as it should be less than the maximum voltage rating .i.e you can add a 9V power supply or battery to the Capacitor whose maximum voltage value is 16V.
  • If you have a high-power supply then you should construct a voltage value that can be used and it must be lower than the Capacitor mentioned voltage.
  • In the Fourth Step, Apply the power supply to the Capacitor for few minutes so that it can get charged and then cut off the supply. Then start measuring the Capacitor voltage by connecting the terminals of the Capacitor and Voltmeter by changing the  Digital Multimeter to Dc Voltmeter mode.
As a result, the noted voltage value should be similar to the mentioned Voltage values on a Capacitor. As it makes the Capacitor useful and you can say it’s a good one but if there is a lot of difference in both rating or value then it means this capacitor needs to be changed.

Note:

When using Multimeter the first value should be noted down as its value will decrease with the passage of time but don’t worry it’s normal.????

"Test

Method 5 Testing a capacitor using Analog Multimeter (AVO Meter)

Before moving forward in this method, at first, we should know about what is Analog Multimeter (AVO Meter).
Answer: It’s an electrical device that is used for measuring different quantities in a circuit just like DigitalMultimeter. For example, Current (A), Voltage (V), Resistance (O).In this method, Analog Multimeter is used for testing Capacitor Capacitance by using its ohmmeter.

Steps :

  • As Always the First Step is to disconnect and discharge a Capacitor. They’re also an easy way for discharging a Capacitor and that is to use a high wattage Resistor or an LED.
  • In the Second Step,  select a higher range position if there are multiple ranges and fix the device in the ohmmeter position. Then connect the Capacitor to the Multimeter probes and then noted down its reading.
  • As a result, the Capacitor is a good one if its resistance value will go from lower to higher and if its value remains lower all the time then it means the Capacitor is a bad one and need to be changed.
  • There’s also an exceptional case when the Capacitor value remains higher all the time then it means it’s an open Capacitor.
  • In this method, both hole and surfaces mount Capacitors can be used.

"Test

Method 6 Shorting the Leads of a capacitor (Traditional Method – only for Professionals)

This method is mentioned at the end of the article as it’s one of the dangerous ways of testing a Capacitor and it should only be used by professionals, in case the other methods result doesn’t satisfy a person’s mentality.

PRECAUTIONS:

For applying this method PRECAUTIONS should be followed. Some of the rules are given below;
1: 24V DC power supply should be used.
2: Series resistor with a high rating should be used with 230V AC to limit the current supply.
3: This method uses a 230V AC supply, so be careful.

STEPS:

  • As Usual, First of all, the power supply should be cut down and Capacitor should be discharged completely.
  • In the Second Step,  take the Capacitor terminals and connect them with the Power supply. Noted that only Non-polarized Capacitor should be used with Capacitance of 230V AC but in case of 24V DC, any type of Capacitor can be used but with the proper setup is needed for polarized Capacitors.
  • In the Third Step, allow the power supply to the Capacitor just for few seconds then switch it off. Even disconnect the terminals of a capacitor from the power supply.
  • Now discharge the terminals using a metal contact. Also, be careful and insulate yourself properly.
  • As a result, the current sparks from the terminals of a Capacitor show its condition it.  The larger and stronger the spark means it’s a good one and smaller and weaker sparks mean it’s a bad one, need to be exchanged.
  • This method can only separate Capacitor with weak Capacitance and it also shows the capability of holding a charge within Capacitors.

"Shorting

Conclusion

After reading the article with full attention, now you’ll be able to understand what is Capacitor and how it’s tested using different methods. This article has also mentioned testing methods for beginners.  Comments down below what do you think about the article and if you have any problems or questions.

FTC: We use income earning auto affiliate links. More.


Latest

Stadia, Google’s foray into cloud gaming, will shut down in January

Google’s latest gaming project has ended in failure. The...

Dyson V12 Detect Slim Review: Why you should Buy

The latest cordless vacuum cleaner from Dyson, doesn't just...

Valve Is Changing Their Steam Sale Schedule: Dates for autumn, winter, and spring

Valve's store confirms when the new Steam Sales are...

Newsletter

Don't miss

Stadia, Google’s foray into cloud gaming, will shut down in January

Google’s latest gaming project has ended in failure. The...

Dyson V12 Detect Slim Review: Why you should Buy

The latest cordless vacuum cleaner from Dyson, doesn't just...

Valve Is Changing Their Steam Sale Schedule: Dates for autumn, winter, and spring

Valve's store confirms when the new Steam Sales are...

Mercedes-Benz’s electric G-Wagen is coming in mid-2024, chairman says

Mercedes-Benz’s electric G-Wagen will arrive in mid-2024, the company’s...
Aizaz khan
Aizaz khanhttps://myelectricsparks.com/aizaz-khan/
Aizaz was the first person to get a byline on his blog on technology from his home in Bannu in 2017. Then, he went on to a career in breaking things professionally at my electric sparks which is where he eventually took over the kit as a hardware editor. Today, as the senior editor of hardware for my electric sparks, he spends time reporting about the most recent developments in the hardware industry and technology. If he's not reporting on hardware or electronics, you'll see him trying to be as remote from the world of technology as possible through camping in the wild.

Stadia, Google’s foray into cloud gaming, will shut down in January

Google’s latest gaming project has ended in failure. The company announced yesterday that its Stadia cloud gaming platform, which lets you stream games like you would...

Dyson V12 Detect Slim Review: Why you should Buy

The latest cordless vacuum cleaner from Dyson, doesn't just clean but also shows you what you’re cleaning The Dyson V12 Detect Slim makes some significant...

Valve Is Changing Their Steam Sale Schedule: Dates for autumn, winter, and spring

Valve's store confirms when the new Steam Sales are coming and advances the dates of all the sales that will take place between now...