What is a power supply and what is the best power supply

As one of the indispensable core components of electronic equipment, the power supply is responsible for converting alternating current (AC) or direct current (DC) into a stable voltage suitable for the equipment. Whether it is household appliances, industrial control systems or high-end laboratory instruments, the power supply is the basis for ensuring the normal operation of the equipment. This article will explore the basic principles, types, applications and importance of power supply in modern electronic technology.

Overview of power supplies

Power supplies refer to devices that can convert one form of energy into another form of energy and provide stable power to electronic devices. According to the form of output voltage, power supplies can be divided into AC power supplies (AC Power Supplies) and DC power supplies (DC Power Supplies). DC power supplies are more common in most electronic devices because of their stability and controllability.

Basic principles of power supplies

The main function of power supplies is to convert alternating current (AC) into direct current (DC) to provide stable power for electronic devices. Its basic working principle includes the following steps:

• Rectification: First, the alternating current is converted into pulsating direct current through a rectifier circuit. Commonly used rectifier circuits include half-wave rectification and full-wave rectification.

• Filtering: The rectified DC still contains a certain amount of AC components. The function of the filter circuit is to remove these AC components and make the DC smoother. Commonly used filter components include capacitors and inductors.

• Voltage stabilization: Due to the fluctuation of the grid voltage and the change of the load, the DC voltage after filtering may be unstable. The function of the voltage stabilization circuit is to maintain the stability of the output voltage. Commonly used voltage stabilization circuits include linear regulators and switching regulators.

• Protection: In order to prevent abnormal conditions such as overvoltage and overcurrent from damaging electronic equipment, power supplies usually also include various protection circuits, such as overvoltage protection (OVP) and overcurrent protection (OCP).

What are the types of power sources?

• Linear power supply: Linear power supply uses linear regulators, which have the advantages of small output ripple and low noise, and is suitable for occasions with high power quality requirements. However, the efficiency of linear power supply is low, usually only 40%~50%.

• Switching power supply: Switching power supply uses switching regulators to achieve efficient power conversion through high-frequency switching technology. The efficiency of switching power supply can reach more than 80%, and it is widely used in computers, communication equipment and other fields. However, the output ripple of switching power supplies is large and the noise is high.

• Uninterruptible Power Supply (UPS): Uninterruptible power supplies are mainly used to provide continuous power supply to important equipment when the power grid is out of power. UPS usually includes a battery pack and an inverter, which can automatically switch to battery power mode when the power grid is abnormal.

• Programmable power supply: Programmable power supply has flexible output voltage and current regulation functions and is suitable for laboratory testing and automation control fields. Users can remotely control and monitor the power supply through programming interfaces (such as USB, RS232, etc.).

• DC-DC converter: It is used to convert one DC voltage to another DC voltage and is widely used in battery-powered devices.

What Are Power Supplies Called?

Power supplies, also known as power adapters, voltage regulators or AC/DC converters, are devices that provide the required power to electronic devices. They convert the alternating current (AC) of the main power supply into a stable direct current (DC) for use by electronic devices. The specific name used may vary depending on the context and the type of power supply device. Here are some common term definitions and examples:

Linear power supply:

• Definition: A linear power supply uses a linear regulator to convert the input voltage to a stable output voltage. They are known for their simplicity and low noise.

• Example: Linear regulators such as LM7805, LM317.

Switching Power Supply:

• Definition: Switching power supplies use high frequency switching techniques to convert input voltage to the desired output voltage. They are highly efficient and compact compared to linear power supplies.

• Example: Switch Mode Power Supply (SMPS), AC-DC Converter, DC-DC Converter.

Uninterruptible Power Supply (UPS):

• Definition: UPS units provide battery powered protection to critical systems during power outages. They maintain continuous power supply without interruption.

• Example: Online UPS, Line Interactive UPS, Standby UPS.

Battery Charger:

• Definition: A battery charger is a specialized power supply designed to charge batteries by providing a controlled current or voltage.

• Example: Smart Charger, Trickle Charger, Fast Charger.

Solar Inverter:

• Definition: A solar inverter converts direct current (DC) generated by solar panels into alternating current (AC) suitable for home or commercial use.

• Example: Grid-tied Inverter, Off-grid Inverter, Hybrid Inverter.

AC-DC Converter:

• Definition: AC-DC converters are used to convert alternating current (AC) from the mains into direct current (DC) suitable for electronic devices.

• Examples: wall adapter, external power supply.

DC-DC Converter:

• Definition: DC-DC converters convert one DC voltage level to another. They are often used in portable electronics and automotive applications.

• Examples: boost converter, buck converter, buck-boost converter.

Regulated Power Supply:

• Definition: A regulated power supply maintains a constant output voltage despite changes in load conditions or input voltage fluctuations.

• Examples: linear regulated power supply, switch-mode regulated power supply.

Programmable Power Supply:

• Definition: A programmable power supply allows the user to adjust the output voltage and current through software commands. They are often used in laboratory environments.

• Examples: lab power supply, benchtop power supply.

Variable Power Supply:

• Definition: A variable power supply can be adjusted as needed to provide different output voltages and currents.

• Examples: benchtop variable power supply, adjustable power supply.

High Frequency Power Supply:

• Definition: A high frequency power supply operates at very high frequencies to increase efficiency and reduce size.

• Examples: RF power supplies, plasma generators.

Isolated Power Supplies:

• Definition: Isolated power supplies provide electrical isolation between input and output circuits to ensure safety and prevent ground loops.

• Examples: Medical isolated power supplies, Industrial isolated power supplies.

Non-isolated power supplies:

• Definition: Non-isolated power supplies do not provide electrical isolation, but are generally simpler and more cost-effective.

• Examples: Simple DC-DC converters, Wall adapters.

Power Factor Corrected (PFC) Power Supplies:

• Definition: PFC power supplies improve the power factor of AC-DC conversion, reducing energy waste and increasing efficiency.

• Examples: Active PFC power supplies, Passive PFC power supplies.

Medical Power Supplies:

• Definition: Medical power supplies meet the stringent safety and reliability standards required for medical devices.

• Examples: Patient contact power supplies, Non-patient contact power supplies.

Military and Aerospace Power Supplies:

• Definition: Military and Aerospace power supplies are designed to meet the demanding specifications and environmental requirements of military and space applications.

• Examples: Rugged power supplies, MIL STD-compliant power supplies.

LED Power Supplies:

• Definition: LED power supplies are specifically designed to power LED lighting devices, providing the necessary current and voltage control.

• Examples: LED drivers, LED controllers.

Automotive Power Supplies:

• Definition: Automotive power supplies are designed to meet the unique requirements of vehicles, including wide operating temperature ranges and high reliability.

• Examples: Battery chargers, alternators, DC-DC converters.

Audio Power Amplifiers:

• Definition: Audio power amplifiers are power supplies specifically designed to amplify audio signals for speakers.

• Examples: Class A, Class AB, Class D amplifiers.

Motor Drive Power Supplies:

• Definition: Motor drive power supplies provide the necessary power for motor drives, including variable frequency drives (VFDs).

• Example: VFD power supply, servo drive power supply

What Does a Power Supply Do?

A power supply is an essential component in electronic systems and devices, serving as the primary source of electrical power. Its main function is to convert and regulate the incoming electrical energy to a form that is suitable for the electronic device it powers. Here’s a detailed look at what a power supply does:

Conversion of Electrical Energy:

• AC to DC Conversion: Most electronic devices require direct current (DC) for operation, while the standard electrical supply is usually alternating current (AC). Power supplies convert AC to DC to match the needs of these devices.

• DC to DC Conversion: Some power supplies are designed to convert one DC voltage level to another, typically used in battery-powered devices or where voltage regulation is required.

Voltage Regulation:

• Stabilization: Power supplies maintain a stable output voltage even when the input voltage fluctuates or the load (the amount of power drawn by the device) changes.

• Adjustment: Some power supplies offer adjustable output voltage, allowing users to set the output according to the specific requirements of the device being powered.

Current Limiting:

• Protection: Power supplies limit the maximum current that can be drawn by the device, protecting both the power supply and the device from damage due to overcurrent conditions.

Filtering and Noise Reduction:

• Noise Suppression: Power supplies filter out unwanted noise and disturbances from the input power, ensuring clean and stable power delivery to the device.

• Ripple Reduction: Power supplies reduce the ripple present in the output voltage, which can cause instability in sensitive electronic circuits.

Power Factor Correction (PFC):

• Efficiency Improvement: Some power supplies incorporate power factor correction circuits to improve the efficiency of the power conversion process and reduce the amount of wasted energy.

Safety Features:

• Overvoltage Protection: Power supplies include circuitry to protect against overvoltage conditions, which can damage the connected devices.

• Short Circuit Protection: They also feature short circuit protection to safeguard the power supply and connected devices from potential damage.

Isolation:

• Galvanic Isolation: Some power supplies provide galvanic isolation between the input and output circuits, ensuring safety and preventing ground loops.

Adjustable Parameters:

• Output Voltage: Many power supplies allow users to adjust the output voltage to suit the specific needs of the device being powered.

• Output Current: Some power supplies also offer adjustable output current, enabling precise control over the power delivered to the device.

Cooling and Thermal Management:

• Heat Dissipation: Power supplies often include cooling mechanisms such as fans or heat sinks to manage heat dissipation and maintain optimal operating temperatures.

Energy Efficiency:

• Standby Modes: Modern power supplies often have standby modes that consume minimal power when the device is not in use, reducing energy waste.

Reliability and Longevity:

• Quality Components: High-quality power supplies use robust components to ensure long-term reliability and performance.

• Temperature Control: Effective thermal management helps extend the lifespan of the power supply and connected devices.

What are the formulas for power supply?

Power calculation formula:

• Power (P) = Voltage (V) × Current (I)

• Power (P) = Resistance (R) × Current (I)²

• Power (P) = Voltage (V)² / Resistance (R)

Ohm's law:

• Voltage (V) = Current (I) × Resistance (R)

• Current (I) = Voltage (V) / Resistance (R)

• Resistance (R) = Voltage (V) / Current (I)

Energy calculation formula:

• Energy (W) = Power (P) × Time (t)

• Energy (W) = Voltage (V) × Current (I) × Time (t)

Efficiency calculation formula:

• Efficiency (η) = Output power (P_out) / Input power (P_in)

• Efficiency (η) = Output voltage (V_out) × Output current (I_out) / Input voltage (V_in) × Input current (I_in)

Transformer related formula:

• Transformation ratio = Output voltage (V_secondary) / Input voltage (V_primary)

• Current ratio = Input current (I_primary) / Output current (I_secondary)

Capacitor charging formula:

• V(t) = V_final * (1 - e^(-t/(R*C)))

• Where V(t) is the voltage at time t, V_final is the final voltage, R is the resistance, and C is the capacitance.

Battery capacity calculation formula:

• Capacity (Ah) = Current (A) × Time (h)

• Capacity (mAh) = Current (mA) × Time (h)

These formulas are the basis of power supply design and analysis. More factors may need to be considered in specific applications, such as temperature, load changes, voltage regulation, etc. In actual design, more complex formulas and models may also be used to ensure the stability and reliability of the power supply system.

What are the manufacturers of power supplies?

Power supply suppliers are companies that produce and provide power supply equipment and solutions. The power products provided by these companies are widely used in computers, communication equipment, industrial control, medical equipment, consumer electronics and other fields. The following are some well-known power supply suppliers:

• Delta Electronics: A world-renowned power supply supplier, providing a variety of high-efficiency power supply products, including switching power supplies, uninterruptible power supplies (UPS), solar inverters, etc.

• Mean Well: Focuses on the research and development and production of switching power supplies, with a wide range of product lines covering standard power supplies, customized power supplies, LED driver power supplies, etc.

• Emerson: Provides a variety of industrial power supply solutions, including DC power supplies, AC power supplies, redundant power supply systems, etc.

• Acbel: Mainly produces computer power supplies, adapters, LED driver power supplies, etc., and is committed to the development of high-efficiency and environmentally friendly products.

• Corsair: A well-known computer hardware brand, especially in the high-end computer power supply market with a high market share, known for its high stability and performance.

• Seasonic: Focuses on the manufacture of high-performance computer power supplies and server power supplies, and is known for its reliability and high efficiency.

• Cooler Master: In addition to power supplies, it also provides cooling solutions and computer accessories. Its power supply products are popular for their high cost-effectiveness.

• FSP: It provides a variety of power solutions, including computer power supplies, industrial power supplies, communication power supplies, etc., focusing on innovation and technology research and development.

• ON Semiconductor: It provides a wide range of power management solutions, including power ICs, discrete components, etc., serving multiple industries.

• Texas Instruments (TI): Although it is famous for semiconductors and integrated circuits, it also provides a variety of power management and power conversion solutions.

These suppliers have a high reputation and market share in the global market, and their products cover a variety of needs from consumer to industrial levels. When choosing a suitable power supplier, you need to make comprehensive considerations based on specific application requirements, quality requirements and cost budgets.

What is the Best Power Supply?

Choosing the best power supply (PSU) depends on several factors, including your specific needs, the type of system you're building or upgrading, and your budget. Here are some key aspects to consider when selecting the best power supply for your needs:

Efficiency Rating:

• 80 Plus Certification: Look for PSUs with 80 Plus certification, which indicates higher efficiency. Certifications include Bronze, Silver, Gold, Platinum, and Titanium, with Titanium being the most efficient.

• Importance: Higher efficiency means less wasted energy and potentially lower operating costs over time.

Modularity:

• Fully Modular Cables: Allows you to connect only the cables you need, reducing clutter and improving airflow.

• Semi-Modular Cables: Offers some flexibility but includes some fixed cables.

• Non-Modular Cables: All cables are permanently attached, which may lead to more clutter inside the case.

Capacity:

• Wattage: Choose a PSU with enough wattage to support your system's components, especially if you plan to overclock or upgrade in the future.

• Calculating Wattage Needs: Use a PSU calculator to estimate your system's power requirements based on its components.

Fan Size and Type:

• Fan Size: Larger fans generally produce less noise than smaller ones at the same RPM.

• Zero-RPM Mode: Some PSUs feature a mode where the fan does not spin until the PSU reaches a certain temperature, reducing noise.

Brand Reputation and Warranty:

• Reputable Brands: Choose well-known brands with a track record of producing high-quality PSUs.

• Warranty: Look for PSUs with longer warranties, typically ranging from 5 to 10 years, which indicate confidence in the product's reliability.

Form Factor:

• ATX: The most common form factor for desktop PCs.

• SFX: Smaller form factor for mini-ITX builds or cases with limited space.

• Other Form Factors: Some specialized servers or workstations may require specific form factors.

Noise Level:

• Decibel Rating: Lower decibel ratings indicate quieter operation.

• Fan Control: Some PSUs offer fan control options to balance noise and cooling.

Cable Length and Connector Types:

• Length: Ensure that the cable lengths are sufficient for your case and component layout.

• Connectors: Check for the appropriate connectors for your motherboard, GPU, and other components.

Features:

• Over-voltage/Under-voltage Protection: Helps protect your components from power surges or drops.

• Short-circuit Protection: Prevents damage from short circuits.

• Overload Protection: Protects against overloads.

• Temperature Monitoring: Monitors internal temperatures to prevent overheating.

Price:

• Budget: Determine your budget and prioritize features accordingly.

• Value: Consider the overall value, taking into account price, warranty, and features.

Top Power Supply Brands and Models

Here are some reputable brands and models that are highly regarded in the industry:

Corsair:

• RMx Series: Known for their high efficiency and quiet operation.

• HX Series: High-end models with excellent performance and features.

Seasonic:

• Prime Series: Highly efficient and reliable, with excellent build quality.

• Focus GX Series: Offers good value with high efficiency and modular design.

EVGA:

• SuperNOVA Series: High-performance PSUs with excellent efficiency and features.

• GQ Series: Affordable options with solid performance.

Thermaltake:

• Smart RGB Series: Offers good value with modular cables and RGB lighting.

• TOUGHPower Series: High-end models with excellent efficiency and build quality.

Cooler Master:

• V Series: Good balance between performance and price.

• MasterWatt Maker Series: High-end models with excellent efficiency and modular design.

Be Quiet!:

• Dark Power Pro Series: Known for their quiet operation and high efficiency.

• Straight Power Series: Offers good value with modular cables and high efficiency.

Antec:

• High Current Gamer Series: High-quality models with excellent build quality.

• EarthWatts Gold Series: Good value with high efficiency and modular design.

FSP Group:

• Hydro GT Series: High-performance models with excellent efficiency and features.

• Aurum Pro Series: High-end models with excellent efficiency and modular design.

XFX:

• Pro Series: High-quality models with excellent efficiency and features.

• GTX Series: Good value with solid performance.

Phanteks:

• Revolt Series: Small form factor PSUs with excellent efficiency.

• Eclipse Series: High-end models with excellent efficiency and modular design.

Conclusion
The "best" power supply varies depending on your specific needs and preferences. When choosing a PSU, consider the factors mentioned above, along with your budget and the specific requirements of your system. Reputable brands and models with high efficiency, modular cables, and strong warranties are generally recommended.

How to Check Your Computer's Power Supply

To check if your computer's power supply is working properly, you can do the following steps:

Visual Inspection:

• Check the power cord and plug for damage or looseness.

• Verify that the power adapter (if applicable) has no visible physical damage.

Check the power indicator light:

• Most power adapters and computer hosts have a power indicator light. If the light is on, the power supply is working.

• If the light is off, the power supply may not be connected or may be damaged.

Use System Diagnostics:

• Both Windows and macOS have built-in system diagnostics tools that can check the status of the hardware, including power issues.

• In Windows, you can use Device Manager to check if there are any power-related errors.

• In macOS, you can use the System Information app to check the status of the hardware.

Check for BIOS Updates:

• Updating the BIOS can help resolve some power management issues. Enter BIOS Setup and check if there are any updates available.

Use a Multimeter:

• If conditions permit, you can use a multimeter to measure whether the voltage output by the power supply meets the standard (usually +12V, +5V, +3.3V, etc.).

• Set the multimeter to DC voltage mode, and then connect the probes between the power supply output and the ground line to measure.

Replacement method:

• If you suspect that there is a problem with the power supply, you can try to replace a known good power adapter or power cord to see if the problem is solved.

Check the power settings:

• Confirm that the power settings in the operating system are correct. For example, in Windows, you can view and adjust the power settings through "Control Panel" > "Hardware and Sound" > "Power Options".

• Make sure the computer is not set to power saving mode or automatic shutdown.

Check the hardware connection:

• Confirm that all internal hardware (such as hard disk, memory module, graphics card, etc.) are properly installed and connected to the power supply.

• If there are additional power interfaces (such as auxiliary power for graphics cards), make sure these interfaces are also properly connected.

• If the above steps still cannot determine the problem, it is recommended to contact a professional technician for further inspection and repair. In some cases, it may be necessary to replace the power adapter or the power module inside the computer.

How to test the power supply with a multimeter?

Using a multimeter to test the power supply is a common troubleshooting method. Here are the detailed steps:

Prepare tools

• Digital multimeter (DMM)

• Power adapter or power supply to be tested

• Probes or wires

Set up the multimeter

1. Turn on the multimeter: Press the power button to make sure the multimeter is on.
2. Select DC voltage mode: Rotate the selector switch to the DC voltage (V⎓) position.
3. Set the range: Select the appropriate range according to the expected voltage value. For example, if you want to measure a 12V power supply, you can select the 20V range.

Test the power supply output

1. Disconnect the power supply load: Make sure the power supply is not connected to any load (such as a computer, device, etc.).
2. Connect the probes: Insert the red probe into the "VΩ" jack and the black probe into the "COM" jack.
3. Measure voltage:

• Touch the red probe to the positive output terminal of the power supply.
• Touch the black probe to the negative output terminal of the power supply or the ground (GND).

Read the voltage value

1. Observe the display: The multimeter will show the current measured voltage value.
2. Judgment result:

• If the displayed voltage value is consistent with the nominal value (for example, a 12V power supply displays about 12.0V), the power supply is normal.
• If the displayed voltage value deviates from the nominal value by a large margin, or no voltage is displayed, the power supply may be faulty.

Test power supply ripple

1. Select AC voltage mode: Rotate the selector switch to the AC voltage (V.AC) position.
2. Set range: Select the appropriate AC voltage range.
3. Measure ripple:

• Touch the red probe to the positive output terminal of the power supply.
• Touch the black probe to the negative output terminal of the power supply or the ground wire (GND).

4.Read ripple value: The multimeter will display the AC ripple voltage. The ripple value should be as small as possible, usually below hundreds of millivolts.

Safety precautions

1. Avoid short circuit: During the measurement process, make sure that the probe does not touch the positive and negative poles of the power supply at the same time to avoid short circuit.
2. Power-off operation: When connecting or disconnecting the probe, it is best to disconnect the power supply first to prevent electric shock or damage to the equipment.
3. Correct use of the multimeter: Follow the instructions for use of the multimeter to ensure correct operation.

Through the above steps, you can use a multimeter to effectively test the output voltage and ripple of the power supply to determine whether the power supply is working properly. If the power supply is found to be abnormal, it is recommended to further investigate or replace the power supply.

What is a programmable DC power supply?

DC power supplies are commonly used in research, design, development and production applications as an instrument that can provide DC current to connected devices.A device connected to a power supply can be referred to as a load, a Device Under Test (DUT), or a Unit Under Test (UUT) depending on the context.To characterize a DUT or test whether it is working as expected, many DC power supplies can simultaneously provide power and measure the voltage or current consumed by the DUT.Typically, a power supply provides constant current or voltage and monitors the resulting voltage drop or current consumption.Programmable DC power supplies can be automated using computers to communicate with devices.Some programmable DC power supplies can store output sequences or measured values in on-board memory, while others can only handle real-time operations.

What is the difference between constant current mode and constant voltage mode?

In addition to understanding the difference between power supply and absorbed power, it is also important to understand the differences between constant voltage mode and constant current mode.The programmable DC power supply can operate in either constant voltage or constant current mode, depending on the required output level and load conditions.

Constant voltage mode

In constant voltage mode (sometimes referred to as voltage control mode), the power supply behaves like a voltage source, maintaining a constant voltage at the output terminals while varying current output based on load conditions.If the load resistance changes, Ohm's Law (V = I x R) dictates that the supplied current must also change proportionally to maintain the power supply output voltage level.If the resistance of the DUT suddenly drops, the power supply will increase current to maintain a constant voltage.

When using a programmable DC power supply, you can set the desired current limit.If your load attempts to draw more current than the programmed current limit allows, the power supply will start operating in compliance mode. This means that it cannot achieve the required output voltage level without violating the user-programmed current limits.At this time, the power supply switches to constant current mode and the current is maintained at the current limit.This critical load resistance level is called the compliance resistance and can be calculated by dividing the voltage setpoint by the current limit.Other common names for compliance resistance are critical resistance and crossover resistance.

Constant current mode

The constant current mode is essentially the opposite of the constant voltage mode.In the constant current mode (also known as current control mode), the power supply behaves like a current source, maintaining a constant current flowing through the output terminals while the output voltage varies according to load conditions.Referring to Ohm's law, if the load resistance changes, the voltage must also change accordingly to maintain a constant current.If the DUT in the above example fails and causes a decrease in load resistance, the power supply will proportionally reduce the output voltage to maintain constant current.For example, when controlling an LED that may be damaged by high current, constant-current operation is ideal.

The constant current mode is also subject to the constraints of configurable voltage limits, applying a compliance resistance similar to that in the constant voltage mode.You can use the same calculations used in the Constant Voltage Mode section to calculate compliance resistance for constant current operation.However, for the constant current mode, the load resistance must remain below the compliance resistance to maintain the desired constant current.Figure 2 illustrates the concept of compliance resistance in constant voltage and constant current modes.

A unique application that requires constant voltage and current operation is charging lithium-ion batteries, which are a common type of rechargeable battery used in portable electronic devices due to their high energy density, no memory effect, and slow loss of charge when not in use.To charge a lithium-ion battery, the power supply should apply a constant current and monitor the voltage level of the battery until it reaches its maximum voltage.After the lithium-ion battery is fully charged, the power supply should switch to a constant voltage mode that provides the minimum current required to maintain the battery at its maximum voltage.

Statement

All articles (images, texts, audio) on this site are uploaded and shared by users, or integrated from relevant internet sources, only for user's learning. If your rights are violated, please contact the administrator to delete! Link to this article: https://www.jinftry.com