How to discharge a capacitor?
A capacitor is a helpful device used in all types of circuits. We have shown you that how can we charge a capacitor? Now we will learn about how we can discharge a capacitor. Why do we need to discharge a capacitor? The answer is simple whenever we disconnect a charged capacitor from a voltage, the charges are stored in the capacitor for a longer time, and it could be dangerous when you touch it with bare hands. So, before handling a charged capacitor, you should discharge it first to avoid danger.
There are many methods to discharge a capacitor; we will discuss them one by one. First, however, it will help you safely discharging a capacitor.
(1) Discharging of low voltage capacitor:
A small capacitor can quickly be discharged by connecting the two leads of a capacitor. You can check the voltage of the discharged capacitor by using a multimeter; it will show the remaining charge of the capacitor. The capacitor will drain out all the charges inside it; you can see the discharging of a low voltage capacitor below:
(2) Discharging a capacitor with a screwdriver:
You can use a screwdriver to discharge a capacitor; it is safe to use it. The quickest way to discharge a capacitor is using a screwdriver and plier. The following steps should be followed:
- Pick an insulated screwdriver insulated with rubber or plastic to prevent the shock. Make sure that there is no crack or damage in it.
- Hold the capacitor with the help of a plier or hand; do not touch the terminals of the capacitor.
- Now touch the tip of the screwdriver with the leads of the capacitor; a spark will produce after connecting the terminals with the screwdriver.
- After a while, remove the screwdriver and take it back to the terminals. If there is no spark by touching again, then congratulations; you have done it.
- A spark produced by touching the screwdriver can damage your eyes. So, it is better to wear safety goggles.
- There is always a chance of shock in working with bare hands-on electrical components. So it is better to wear gloves.
(3) Discharging capacitor safely with a resistor:
A capacitor can be discharged through a resistor, too, A safe way to lose. A resistor slows down the discharging process, and only a limited amount of current will flow from the circuit. Following steps must be followed to discharge the capacitor:
- First of all, disconnect the capacitor from the battery.
- Check the voltage of the capacitor through the multimeter. Connect the probes of the multimeter to the leads of the capacitor. The digital multimeter will show the voltage present in the capacitor.
- Keep in mind that if the voltage is higher than 12 volts, it is dangerous enough to shock you.
- For safety purposes, use an insulated plier to hold a resistor connected to the capacitor. It helps you in the safe discharge of capacitors.
- Connect the resistor across the terminals of the capacitor; after a few seconds, you will see that the capacitor is fully discharged.
- Check the voltage of the capacitor with the help of a multimeter; if the meter shows you zero voltage, then you have done it.
Never touch the capacitor with bare hands; it may give a severe shock. Make sure that the plier is insulated.
(4) Discharge capacitor with a light bulb:
A light bulb is a type of resistor that will discharge the capacitor efficiently. A high voltage capacitor is discharged safely in this method. You will use the wattage of the bulb according to the capacitor’s strength; that can tolerate the voltage.
- First of all, check the voltage of the capacitor through the voltmeter.
- A high voltage capacitor uses a high voltage bulb. It is better to use a 100W bulb for safe and early discharge.
- Connect the leads of a capacitor with the leads of the bulb.
- The bulb will start glowing, and it will glow till the capacitor fully discharges.
- Disconnect the connections from the capacitors leads.
Now you can recheck it with the help of a voltmeter; if you have followed the points correctly, it will show you zero voltage. It confirms that the capacitor is fully discharged.
- Use insulated gloves to avoid hazardous shock.
- Do not put the leads of the capacitor on a single point (lead) of the bulb.
- Do not touch the leads of the capacitor before discharge.
(5) Making and using of discharging tool:
For ease of discharge of a capacitor, you can make a discharging tool for yourself. A discharge tool is a simple device with a resistor and a bit of wire connected. You can connect it to the capacitor leads and discharge it. You will need the following parts to make a discharging tool.
- A wire (you can select the wire according to your need)
- Resistor (20k OHM 5Watt)
- Two alligator clips
- Electrical insulation tape
- Soldering iron
Making the tool is easy to make, the following steps must be followed:
- Cut the wire into two equal pieces with the help of a wire cutter. Each wire should be long enough to connect one end to the resistor and another side to the capacitor.
- Clip off about a half-inch of insulation on each side of the wire with the help of a knife.
- Solder one side of each wire to the probes of the resistor with the help of soldering iron.
- Insulate the wire and probes of the resistor with the help of electrical insulation tape. Wrap it carefully that no naked wire remains.
- Connect the alligator to the other side of the wire with the help of soldering iron.
Following all these steps carefully will make the best discharge tool for you. Now to discharge the capacitor, connect the alligator to each of two probes of the capacitor. Next, clip the end of each wire to a different terminal of the capacitor; it will discharge the capacitor quickly.
You can check the charge in the capacitor by using a multimeter to confirm whether it is fully discharged. If the multimeter shows zero in the meter, then congratulation, you have done it.
- Be sure that each clip is well connected to the probes of the capacitor.
- Do not touch the probes of a capacitor with bear hands.
The above mentioned are different ways to discharge a capacitor; you need to know about all the methods, as they are target ways to discharge a capacitor. However, I will encourage everyone to do it by themselves, and you do not need to be a pro in this process; even a beginner can do it.