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How to discharge a capacitor

A capacitor can be described as a tool for storing electrical energy. By generating electric field in-between the two plates, it does this. The capacitor charges when it receives a voltage.

The capacitor is measured by its capacitance, which is often expressed in farads. In AC circuits, capacitors function as rechargeable batteries. They serve the purpose for which they were designed, which is to store electrical energy as well as transmit it to the other components of your circuit.

Why Is It Necessary To Discharge Capacitors?

As we previously stated, capacitors serve as energy storage devices and can shock you severely if you handle them when they are still charged. To discharge these capacitors first before handling them is crucial.

After this current stops passing via the circuit, they can retain this current in them for some minutes. We must always release them before you work because of this.

What Capacitors Are Generally Recognized as Safe?

Discharge a Capacitor

This query has no answer. Any capacitor has some degree of potential harm. However, capacitors with a voltage of about 50 volts can’t send current via the body as well as result in death.

Smaller-than-50V capacitors frequently result in stinging, minor electrical shocks, and a faint tingling in the fingertips. They are relatively safe in our opinion.

Keep in mind that just empty capacitors remain completely secure.

Precautions to Take Before Discharging a Capacitor

Remove the capacitor out from its electrical source

  • You should first turn off the supply of power before we will be able to explain how to discharge a capacitor.
  • If the gadget is within the house, it can be unplugged from the power socket; when it’s in your car, you must unplug the wires that are attached to the – and + terminals of your car battery.
  • Disable your power line and turn off any equipment that is powered by an external battery and an independent power source.

Put on safety gear

When discharging a capacitor, it’s crucial to wear protective gear for some reasons. One explanation is because capacitors have a high energy storage capacity and can spark when they begin to discharge.

Another factor is that when a capacitor’s metal contacts make contact with skin, they might cause electric shocks.

Most individuals find wearing protective gear amusing, but whenever they are hurt by sparks or electric shock, they have a change of heart. Gloves and goggles, for example, can assist shield you from such dangers.

Safe environments

Before emptying the capacitor, make sure the area is free of any objects or materials that could catch fire.

Different Techniques on How to Discharge a Capacitor


How to Discharge a Capacitor Using a Screwdriver

Disconnect the power source

Always cut off the source of power before discharging capacitors while working with them. Injury and accident prevention will benefit from this. Energy can be stored in capacitors in vast quantities.

On your electronic equipment, locate your capacitor

Capacitors are typically found close to the power source since they are known for energy storage as well as the regulation of current flow.

If you’re having trouble locating the capacitor, go to the owner’s manual or the schematic diagram.

Locate the negative and positive terminals of the capacitor

Wearing gloves, grab the body’s condenser without contacting the terminals on the feet. The electrical circuit’s negative and positive connectors are represented by these metal contacts.

To join terminals together, use the insulated screwdriver

Use the insulated screwdriver when discharging the capacitor to prevent coming into contact with its live contacts.

Determine the capacitor’s negative and positive terminals first. Use the insulated screwdriver to connect the negative and positive terminals after that. Until this capacitor discharges, hold your screwdriver there for a short period of time. A brief sound flash or spark can result from capacitor discharge. Don’t be scared as it is normal.

Take out the screwdriver out from terminals of the capacitor

To confirm that it’s empty, repeat the initial step. Simply remove the screwdriver out from its terminals after that. To measure the voltage, connect a multimeter.

Capacitor voltage should be measured using a multimeter

Connect the metal connections and probes. It doesn’t matter how the connections are made (the polarity).

If you obtain a value greater than zero, your capacitor has not been discharged entirely, and you should repeat the process a few more times to be sure that it has.

How to Discharge a Capacitor Using the Pen Tool

PCB Capacitor

The pen tool can be used to shorten out a capacitor’s two plates in order to discharge it. This will produce a spark, immediately releasing the energy. Make sure you discharge capacitors with caution, because they have the ability to store significant energy.

The simplest and quickest method is this. A resistor with high-value built into a discharging tool enables fast current discharge.

How to Discharge a Capacitor Using a Light Bulb

This third method involves using the light bulb. You can use the light bulb if you do not have a screwdriver or discharge tool at home.

  • You must take a single light bulb which is wired to the bulb socket.
  • Join the positive termination of one of its wires to the negative terminal of the second wire. When the light goes out, it implies the capacitor has gone empty. The bulb would start to come on.

The bulb has the benefit of having the light pointer which indicates when this capacitor becomes full empty.

How to Discharge a Capacitor Using a Resistor

  • Verify that the capacitor has been unplugged and not receiving any electricity.
  • Cross the capacitor’s terminals with its high-value resistors.
  • Place the resistor’s ends in contact with the capacitor’s metal contacts.
  • Let the capacitor discharge completely.
  • Cut the resistor’s connection to the capacitor.
  • Turn on the capacitor by plugging it in.

The capacitor is shielded from potential damage by the resistor, which stops a high surge in current from passing through it. Avoid any possible issues by gradually discharging your capacitor utilizing a resistor.


Capacitors serve as energy storage devices and can shock you severely if you handle them when they are still charged. This is why discharging these capacitors first before handling them is crucia




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