Bleeder Resistor: What is it, and Where is it Used?

Bleeder Resistor: What is it, and Where is it Used?

If you’ve opened this article, then you may not have heard of bleeder resistors before. To explain it shortly, bleeder resistors are a type of resistor that is specifically designed to dissipate energy safely. In this article, we will answer some common questions about bleeder resistors and provide some tips to help you choose the right one for your needs.

Resistors and Their Benefits in General

Resistors are one of the most important electronic components. They come in all shapes and sizes, but their primary purpose is to resist or limit the flow of current in a circuit. This resistance can be used to create heat, like in a light bulb filament, or it can be used to control the voltage in a circuit.

Resistors are classified by their resistance value, which is measured in ohms. The higher the resistance value, the more they will resist the flow of current.

Resistors and Their Benefits in General

There are many different types of resistors with different applications. Some common types, including the bleeder resistor. We will talk more about it right now. [1]

What is a Bleeder Resistor?

A bleeder resistor is a type of resistor that is used to discharge the capacitors in a circuit when the power is turned off. This prevents the capacitor from storing a charge and causing damage to the equipment when the power is turned back on.

The bleeder resistor is connected across the capacitor, and its resistance is chosen so that it will allow enough current to flow through to discharge the capacitor without being too low so that it draws too much current from the power supply.

Bleeder resistors are often used in high-voltage circuits where there is a risk of shock if the capacitors are not discharged properly. For example, you will often see them in power supplies and other high-voltage applications.

Bleeder resistors are usually made of carbon film or metal oxide film. They can also be made of other materials, such as ceramic or glass, depending on the application. [2], [3], [4], [5]

How Does Bleeder Resistor Work in a Power Supply

The power supply is an electronic device that supplies electrical energy to an electrical load. The primary function of a power supply is to convert one form of electrical energy into another and, as a result, power supplies are sometimes referred to as electric power converters. Some power supplies use transformers to convert between high and low voltages. Others use switching devices to control the flow of current. And still others use a combination of both.

How Does Bleeder Resistor Work in a Power Supply

A power supply can be either AC-powered or DC-powered. Most electronics devices today are powered by DC, which means they require a DC power supply. A few devices, such as computers and some types of industrial equipment, can use either AC or DC.

AC-powered devices usually have a power supply that converts AC to DC. This type of power supply is called a rectifier. A rectifier can be either a full-wave rectifier or a half-wave rectifier, depending on the type of AC power it is designed to use.

DC-powered devices usually have a power supply that converts DC to another form of DC. This type of power supply is called an inverter. Inverters are used to convert lower voltages to higher voltages, or vice versa.

A bleeder resistor is often used in such high voltage circuits where there is a huge danger of shock if the capacitors are not discharged properly. They are also used in audio circuits to prevent popping noises when the power is turned on or off.

Bleeder resistors are used to discharge the capacitors in a circuit when the power is turned off. This prevents the capacitor from storing a charge and causing electric shock damage to anyone who touches the circuit at that juncture. [2], [3], [4], [5], [7]

Why are Bleeder Resistors Used?

Bleeding resistors are a useful tool that has many applications. Let’s go through the most common of them.

For safety precautions

The most common use of bleeders is for safety. In many cases, if there is a large capacitor in the circuit, it can hold a charge for a long time even after the power has been turned off. This can be dangerous if someone were to come in contact with the exposed terminals. A bleeder resistor safely discharges the capacitor so that there is no risk of electrocution.

Another common use for bleeder resistors is to prevent damage to sensitive electronic components. In some cases, a high voltage DC power supply can cause damage to delicate electronic components such as semiconductors. Bleeder resistors will help you can discharge the capacitor slowly and safely so that no damage occurs.

For better voltage regulation

A different use for bleeder resistors is to improve voltage regulation. When you have a large capacitor in your circuit, it can act like a reservoir of charge. This can cause the voltage to fluctuate when there are sudden changes in the load. By using a bleeder resistor, you can bleed off some of the charge so that the voltage remains more stable.

For voltage division

They are also used in voltage dividers to allow a circuit to have more than one voltage level. For example, if you want to create a voltage divider that has two different voltages, you can use a bleeder resistor to accomplish this.

The bleeder resistor is placed in series with one of the resistors in the voltage divider. When the power is turned on, the capacitor will charge up and the voltage will be divided between the two or more resistors all connected together. [2], [3], [4], [5]

What You Should Keep in Mind When Choosing a Bleeding Resistor

Now that you know some of the common uses for bleeder resistors, let’s talk about how to choose one.

What You Should Keep in Mind When Choosing a Bleeding Resistor

The most important thing to consider is the value of the resistor. This will determine the amount of current that flows through it and how much voltage is dropped across it. You need to choose a value that is high enough so that it doesn’t impact the circuit too much, but low enough so that it can safely discharge the capacitor.

Resistance is another important factor to consider. The higher the resistance, the longer it will take for the capacitor to discharge. This is usually not a problem, but in some cases you may need a faster discharge time. In that case, you would choose a lower resistance value.

The last thing to consider is the power rating of the resistor. This is important because you don’t want the resistor to overheat and cause damage to the circuit. Make sure to choose a resistor with a power rating that is higher than the maximum amount of power that will be dissipated in the circuit.

Now that you know everything there is to know about bleeder resistors, go out and use them in your circuits! Just remember to always safety first and choose values that

You will need to evaluate the value of your resistor first before making a choice.

This can be done with the following equation:

Vt = Vu * e(−t/rc)

Here, Vt is the voltage across the resistor at time, Vu stands for the primary voltage, t is time, R is resistance and c is capacitance.

You can use this equation to determine the value of the appropriate resistor that you need. This is a step required to ensure you won’t have to deal with problems that could have easily been avoided! [2], [3], [4], [5], [6]

FAQ

Do I need a bleeder resistor?

This is a common question with no easy answer. It depends on the application and the level of protection that is required. For example, if you are using a sensitive electronic device that could be damaged by a high voltage pulse, then you would need a bleeder resistor to protect it.

Why is it important to put in a bleeder resistor?

A bleeder resistor is essential in ensuring the safety of your electronic devices. Without a bleeder resistor, charged capacitors can remain dangerous long after the power is disconnected. This can pose a serious hazard to you and your loved ones. In contrast, a bleeder resistor will safely discharge any capacitors within your device, so you can rest assured that it is safe to handle.

Where is the capacitor used?

The capacitor is used to store electrical energy in an electric field. It is composed of two conducting plates separated by an insulating material called a dielectric. The capacitor is used in various electronic circuits for different purposes.

One of the most important uses of the capacitor is in the power supply circuit. The capacitor is used to store energy in the form of an electric field and to release it when required. A Bleeder resistor is required to ensure that the capacitor is discharged completely when the power supply is turned off and provide extra electric hazard precautions.

Useful Video: What is a “Bleeder” Resistor?

Conclusion

Bleeder resistors are elements that you will often find in many circuit boards for safety purposes. They help discharge capacitors properly and avoid any hazards. If you’re working with or around circuits, it’s important to be informed about bleeder resistors and their function so that you can work safely. Also, they can be utilized as voltage dividers or regulators if you have the need for it.

When selecting a bleeder resistor, pay attention to both the value and resistance to make sure you know how to choose a proper one required for your specific application. Hopefully this article helped you to get informed a little more about them. Thanks for reading!

References:

  1. https://www.techtarget.com/whatis/definition/resistor
  2. https://electronicsreference.com/analog/bleeder_resistor/
  3. https://www.elprocus.com/bleeder-resistor-working-and-its-applications/
  4. https://circuitdigest.com/article/what-is-bleeder-resistor-and-where-it-is-used
  5. https://www.watelectronics.com/what-is-bleeder-resistor-circuit-diagram-and-its-functions/
  6. https://electrical-engineering-portal.com/a-look-at-the-power-rating-of-resistors
  7. https://www.teamwavelength.com/power-supply-basics/