A PCU, or Power Conversion Unit, is a component typically found in electronic devices that converts DC to AC. This allows the device to use DC power sources such as batteries and solar panels without damaging components or decreasing performance. AC is more usable than DC because it is capable of being transferred over long distances without losing its voltage. This ability to transfer long distances without losing power is why AC power is used in homes and businesses.
Why Is a PCU Needed To Power Electronic Devices?
A PCU is needed to power electronic devices because DC power cannot be transferred over large distances as AC power can. Without a PCU, batteries and solar panels would be dedicated and restricted to powering electronic devices in nearby areas such as aircraft or within the walls of your home. An example of this is illustrated below:
Diagram depicting how a computer uses its components (including the PCU) to convert the battery's DC energy to AC energy that can be utilized by numerous applications such as laptops, monitors, and speakers. If the PCU was not present to convert energy (DC to AC), then these components would not be able to function.
How Does a PCU Work?
A PCU works by using an electromagnet within coils of wire. When electricity is passed through the wire, it creates a magnetic field around the coil which attracts another piece of metal (see image below). This process continues on and on until there are thousands of different coils stacked together in large bundles with small pieces of metal being pushed up and down inside each one. The back and forth motion that occurs from these pieces hitting each other creates an alternating current that is easily transferable over long distances without losing its voltage. This is how AC power is created.
The electromagnet is controlled by electricity which causes it to rapidly switch on and off. This switching motion moves metal around creating a magnetic field within each coil of wire, causing thousands of these coils to form large bundles with small pieces of metal being pushed up and down between them. This back and forth motion creates an alternating current that will be used as AC power for devices such as computers or speakers.
Please note that this is a very simplified version of what occurs in a PCU. In real life, there are small metal balls inside of these pieces and thousands of more coils than were depicted here.
What Is the Function of the PCU Within a Computer?
A computer's Power Conversion Unit activates and deactivates depending on if it is plugged into an outlet or not (see image below). When plugged into an outlet, it begins converting AC power from the wall to DC power. This process will continue until all components such as the motherboard, hard drive, monitor, etc. shut off due to not receiving enough power (see electrical engineering homework help for more information about idling voltage).
Once the PCU has converted enough AC power to become what is known as "idling voltage," it will shut off and begin converting DC power from the battery into AC power. This process will continue until all components such as the motherboard, hard drive, monitor, etc. turn on due to receiving enough power (see electrical engineering homework help for more information about idling current). Once enough current has been stored in the battery through this conversion process, these components will turn back off which causes the PCU to once again switch its state of being and begin converting AC power from the wall into DC power (and vice versa).
This process will continue until the PCU is unplugged, at which point it will shut off and remain off until plugged in again.
Please note that there are always two AC coils within a Power Conversion Unit (one for home use and one for battery usage). In this image, only one side has been depicted to simplify the explanation of the PCU's functionality. Also, in real life, the PCU is much smaller than depicted here and is sometimes not visible outside of its housing.
How Does the PCU Affect My Computer's Battery Life?
The Power Conversion Unit has a maximum power rating which means that there is only so much AC power it can convert to DC before overheating due to the excessive loss of voltage. This rating usually falls within 60-70 watts, meaning it cannot supply more than this amount of power to a laptop's battery. The PCU will continue converting as long as it is plugged into an outlet at home, but once taken on the road its functionality becomes limited by its maximum power rating. Thus, if a computer is running off of a battery that has been drained down to less than 60-70 watts, the PCU must first charge the battery back up to this threshold before powering on any other components such as the motherboard or hard drive.
In conclusion, Power Conversion Units have a fixed amount of AC power they can convert from an outlet and DC power they can convert to from a battery before overheating due to excessive loss of voltage. If this loss equals or exceeds 70 watts, these units may need to charge a computer's battery up to this threshold before allowing any components other than the motherboard or hard drive to turn on.
Power Conversion Unit, is a component typically found in electronic devices that converts DC to AC. This allows the device to use DC power sources such as batteries and solar panels without damaging components or decreasing performance.