AC-DC Power Supply Guide by FSP Power Solution: Certified Products & Expert Picks
Explore AC-DC power supplies from FSP Power Solution — adapters, open frame, and industrial PC PSUs. Discover definitions, applications, and how to choose the right certified high-efficiency design.
Author: FSP Power Solution GmbH
An AC-DC power supply (adapter or internal converter) transforms alternating current (AC) from the grid into direct current (DC) required by electronic devices. At FSP Power Solution, we deliver a complete portfolio including AC-DC adapters, open frame power supplies, and industrial PC PSUs. All products are certified, high-efficiency designs tailored for industrial, medical, ICT, and consumer applications — ensuring stable power delivery, regulatory compliance, and long-term reliability.
AC vs. DC Power – Key Differences for Power Supply Applications
Every electrical device needs power to operate. However, the electricity supplied from the grid (AC) cannot be used directly by most electronic circuits, which require a stable DC voltage. This mismatch is the reason why AC vs. DC matters—and why an AC-DC power supply is essential in nearly all modern equipment.
| Feature | AC Power (Alternating Current) | DC Power (Direct Current) |
|---|---|---|
| Source | Mains electricity from the grid | Batteries, solar cells, fuel cells |
| Flow | Electrons move in alternating direction (waveform) | Electrons move in one steady direction |
| Distance | Efficient for long-distance transmission | Limited to short-range delivery |
| Best Use | Power distribution networks, household supply | Electronics, ICT, medical devices |
Because AC is ideal for transmission and DC is required inside devices, an AC-DC power supply is necessary to convert grid power into safe DC electricity.
What is an AC-DC Power Supply? Definition and Basics
An AC-DC power supply is a device that converts alternating current (AC) from the grid into direct current (DC) required by electronic circuits. Electronic components such as processors, sensors, and communication modules cannot operate directly on AC. They require steady DC voltage to ensure stability, safety, and efficiency.
A common example is found in data communication devices or medical monitors: while the facility receives 230 V AC, the electronics inside operate on low-voltage DC (e.g., 5 V, 12 V, or 24 V). This conversion is only possible through an AC-DC power supply, which ensures that sensitive components work safely and reliably.
How does an AC-DC power supply work?
An AC-DC power supply delivers stable DC power through a series of conversion stages. Although the design may differ between adapters, open frame boards, and industrial PSUs, the basic process is the same:
- Transformer: adjusts the input voltage up or down.
- Rectifier: changes AC into DC.
- Filter: smooths the DC and removes noise.
- Regulator & Protection: keeps voltage steady and protects the device from short circuits, overheating, or overload.
These stages ensure that electronic devices (e.g., laptops, medical systems, or household electronics) receive safe and reliable power.
What happens if you don't use an AC-DC power supply?
Many electronic devices cannot work directly with AC power. They are designed to run only on DC. If AC power is connected to a device that requires DC, serious problems can occur. Sensitive electronic parts may burn out or break immediately, and in some cases, the equipment could overheat, catch fire, or even explode. This also creates risks for user safety, especially in industrial or medical environments.
That is why using a proper AC-DC power supply is essential. It ensures that devices receive the correct voltage and stable power, protecting both the equipment and the people who use it.
How to Choose the Right AC-DC Power Supply – Selection Guide & Key Factors
Choosing the right AC-DC power supply depends on your application. Below are the most important factors:
1. Power & Voltage Range for AC-DC Power Supplies
- Check the watts and volts your device needs.
- Small devices may use 5–24 V, while industrial PCs may need 54 V or higher.
2. AC-DC Power Supply Form Factors (Adapter, Open Frame, IPC PSU)
- Decide if you need an adapter, open frame board, or industrial PC PSU.
- External adapters are simple to use, while open frame PSUs allow integration.
3. AC-DC Power Supply Certifications & Safety Standards
- Look for DOE VI, CoC Tier 2, IEC 62368, IEC 60601 (for medical).
- Certified products ensure safety, compliance, and efficiency.
4. Application Environment & Reliability Factors
- Consider temperature, humidity, and redundancy needs.
- Industrial and medical devices often need high MTBF and continuous operation.
With decades of experience, FSP Power Solution provides complete support to help you select the best AC-DC power supply for your system.
Main Types of AC-DC Power Supplies: Adapters, Open Frame & Industrial PSU
AC-DC power supplies come in several formats to match different applications. Modern designs are compact yet powerful, covering everything from consumer devices to demanding industrial systems. In practice, most needs fall into three main categories: adapters, open frame modules, and industrial PC power supplies.
AC-DC Adapters
Portable electronics and consumer devices often require compact external power sources. AC-DC adapters fill this role, providing safe and convenient conversion from grid AC to device-ready DC. FSP Power Solution designs adapters that cover a wide power range and multiple form factors to meet diverse application needs.
- Wall Mount Adapters – Plug directly into the socket, ideal for small devices like routers, set-top boxes, or portable electronics.
- Desktop Adapters – Larger power range with a cord between the plug and device, typically used for monitors, printers, or POS systems.
- USB Type-C PD Adapters – Support PD 3.0 / PD 3.1 fast charging up to 240 W for ICT and consumer devices.
- Power Range – From 10 W to 330 W, voltages 5 V to 54 V, meeting DoE VI and CoC Tier 2 standards.
- Certifications – All FSP models are certified with the IEC 62368 standard and major global safety certificates
Open Frame AC-DC Power Supplies
Embedded systems and industrial devices often need board-level power modules that fit directly into their chassis. Open frame power supplies provide this flexibility with compact, customizable designs. FSP Power Solution offers open frame PSUs that combine standardized sizes with tailored options for specialized requirements.
- Form Factors – Standard 2" × 4" and 3" × 5" sizes, plus custom layouts.
- Customization – Easy to adapt for ICT, medical, or industrial applications.
- Power Range – From 30W to 450W, output 5 V to 54 V, including dual-output versions (e.g., 12 V + 54 V).
- Certifications – All Products comply with IEC 62368 and IEC 60950 standards for safety in industrial and ICT environments.
Industrial PC AC-DC Power Supplies
Industrial PCs and servers require higher power density, reliability, and certification than consumer devices. FSP Power Solution integrates these requirements into its IPC PSU portfolio, delivering scalable power solutions that balance efficiency, compliance, and reliability for mission-critical applications.
- Form Factors – Wide selection including Flex, ATX, SFX, 1U/2U, CRPS modules, PS2-redundant, and mini-redundant designs, covering everything from compact IPCs to full server racks.
- Power Range – Models from 100W up to 3,000W, with input options such as 115 V AC, 230 V AC, LVDC, and HVDC.
- Reliability – Designed for continuous operation in harsh environments, featuring high MTBF ratings and 80 PLUS Gold / Platinum efficiency.
- Certifications – All products comply with IEC 62368 and IEC 60950 standards for safety in industrial and ICT environments.
Why Choose FSP Power Solution's AC-DC Power Supplies?
FSP Power Solution delivers certified, high-efficiency AC-DC power supplies for global markets with strong local support in Europe. Our products combine innovation, compliance, and reliability—helping customers design safe and cost-efficient systems.
1. Proven Experience
With decades of experience in power conversion, FSP Power Solution provides AC-DC power supplies designed for stability, energy efficiency, and long-term reliability.
2. AC-DC Power Supply Quality & Global Compliance
All FSP Power Solution products carry international certifications: IEC 62368, IEC 60601, DOE VI and CoC Tier 2. Our internal PDCA quality system ensures consistent performance and safety.
3. Continuous Innovation in AC-DC Power Supply Design
FSP Power Solution invests in R&D to deliver compact, high-density designs that meet the latest efficiency standards. Our energy-efficient and customizable AC-DC power supplies reduce operating costs while supporting sustainable system design.
4. Wide Range of AC-DC Power Supply Solutions
From adapters, open frame modules to industrial PC PSUs and redundant server power supplies, FSP Power Solution offers a complete portfolio to cover consumer and industrial applications.
5. Local FAE and Technical Support in Europe
Our Field Application Engineering (FAE) Service Center in Germany provides direct support for design-in, testing, and customization. Customers benefit from faster communication, certified testing, and tailored AC-DC power supply solutions that shorten development time and reduce risks.
FAQ – AC-DC Power Supply Questions Answered
1. What is an AC-DC power supply, and why is it needed?
An AC-DC power supply changes alternating current (AC) from the wall socket into direct current (DC) used by electronic devices. Most electronics, such as laptops, printers, or medical monitors, cannot run directly on AC. They need stable and safe DC power. Without an AC-DC power supply, devices may stop working or even get damaged.
2. What are the main types of AC-DC power supplies?
There are three main types:
- Adapters: external units like wall-mount or desktop chargers, also USB Type-C PD adapters.
- Open Frame PSUs: circuit board modules without a case, used inside ICT and consumer devices.
- Industrial PC PSUs (IPC PSU & CRPS): high-power supplies for servers, networking, and industrial PCs.
3. How to choose the right AC-DC power supply for my application?
To choose the right model, check these key factors:
- Power and voltage range (watts and volts needed by your device).
- Form factor (adapter, open frame, or industrial PC PSU).
- Certifications for safety and efficiency.
- Application environment (temperature, redundancy, MTBF).
FSP Power Solution provides a wide product range and local support to help you make the best choice.
4. What certifications should I check when selecting an AC-DC power supply?
Important standards include:
- DOE Level VI and CoC Tier 2 for efficiency.
- IEC 62368 for ICT and industrial safety.
- IEC 60601 for medical devices.
Choosing certified AC-DC power supplies ensures safe operation, compliance with regulations, and higher energy savings.
5. Are FSP Power Solution adapters compliant with DOE VI and CoC Tier 2?
Yes. Most FSP Power Solution adapters meet both DOE Level VI and CoC Tier 2 requirements. This means they provide high efficiency, lower standby power, and global compliance for ICT, consumer, and industrial applications.
6. Does FSP Power Solution provide customized and localized AC-DC power supply services in Europe?
Yes. FSP Power Solution offers both customized AC-DC power supply solutions and localized support in Europe. Our FAE Service Center in Germany helps customers with design-in, testing, and firmware or hardware modifications to meet special requirements. Local engineers also provide compliance checks and failure analysis, so European customers benefit from faster service and tailored solutions.
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About FSP
FSP Group is one of the global leading power supply manufacturer. Since 1993, FSP Group has followed the management conception "service, profession, and innovation" to fulfill its responsibilities as a green energy resolution supplier.