AC-DC switching power supply by PHC Enterprise, 5VDC 5000mA, with 2.1x5.5mm center positive connector, part # SW-55A

Close-up of 2.1mm x 5.5mm straight barrel plug connector on AC-125AC 12VAC power adapter

PHC Enterprise 5VDC AC-DC switching power supply with 2.1x5.5mm center positive connector, rated 5000mA, part # SW-55A.

5V 5A AC-DC Power Supply - 2.1mm x 5.5mm Center Positive | SW-55A

Name: 5V 5A AC-DC Power Supply - 2.1mm x 5.5mm Center Positive | SW-55A
Brand: PHC Enterprise, Inc.
SKU: SW-55A
Price: 24.00 USD
Availability: InStock

by PHC Enterprise, Inc.

$24.00 - $24.00

$24.00

$24.00 - $24.00

$24.00

Regulated 5V 5A AC-DC Switching Power Supply |

Part SW-55A

The SW-55A is a wall-mount regulated switching power supply that converts standard 100–240V AC wall power to a stable 5V DC @ 5000mA (5A) output. With universal input voltage and a standard 2.1mm x 5.5mm center-positive barrel connector, it delivers a full 25W of clean 5V power for LED lighting, single-board computers, powered hubs, and other 5V DC electronics.

Technical Specifications

Part Number: SW-55A
Input Voltage: 100–240V AC, 50/60Hz (universal — works worldwide)
Output Voltage: 5V DC
Output Current: 5000mA (5A)
Output Power: 25W
Connector: 2.1mm (ID) x 5.5mm (OD) barrel plug — center positive (+)
Regulation Type: Switching (regulated)
Form Factor: Wall-mount

Common Applications & Device Types

A 5V DC 5A supply with a 2.1mm x 5.5mm center-positive barrel plug is one of the most widely used bench and OEM power standards. It is commonly specified for:

Addressable LED strips — WS2812B / NeoPixel and similar 5V pixel strips, where a 5A supply feeds roughly 80–90 pixels at full white
5V LED sign modules and under-cabinet strip lighting
Single-board computers — Raspberry Pi, Orange Pi, and similar boards powered through a barrel-jack breakout or power HAT
Powered USB hubs and USB charging hubs rated 5V at up to 5A
External 2.5" hard drive enclosures, SSD docks, and drive duplicators
Small unmanaged network switches, routers, and media streamers
Arduino, ESP32, and Raspberry Pi Pico project builds needing more headroom than a USB port provides
Retro gaming consoles, arcade boards, and DIY cabinet builds converted to a 5V barrel input
5V DC cooling fans, relay boards, and servo/actuator test rigs

Before connecting, confirm your device is rated for 5V DC, accepts a 2.1mm x 5.5mm barrel plug, and uses center-positive polarity. Voltage, connector size, and polarity must all match.

Why a Switching Power Supply?

Switching power supplies are far more efficient than linear supplies, so they run cooler and hold their output voltage steady as the load changes. The SW-55A's regulated output keeps your device at a consistent 5V across the full current range, which matters for LED strips and logic boards that brown out or shift color when voltage sags.

Frequently Asked Questions

What is the plug size and polarity?

The SW-55A uses a 2.1mm inner diameter x 5.5mm outer diameter barrel plug with center-positive (+) polarity. The inner pin carries +5V and the outer sleeve is ground.

Can I use this if my device only draws 1A or 2A?

Yes. A device draws only the current it needs, so a 5A supply works fine for a lower-current 5V device as long as the voltage, connector, and polarity match. The extra headroom simply means the supply runs cooler.

How many WS2812B / NeoPixel LEDs will 5A run?

At full-brightness white each WS2812B pixel can draw about 60mA, so 5A supports roughly 80 pixels at worst case. At typical mixed-color brightness the same supply comfortably runs several hundred pixels. Longer runs should use power injection and a larger supply.

Will this work outside the United States?

Yes. The 100–240V AC, 50/60Hz universal input supports North America, Europe, Asia, and most other regions. A physical plug adapter may be required for non-North American outlets.

Is the output regulated?

Yes. This is a regulated switching supply, so the output stays at a stable 5V DC across varying load conditions rather than drifting high at light load like an unregulated adapter.

Can I power a Raspberry Pi with this?

Yes, if the board is fed through a barrel-jack input such as a power HAT or a barrel-to-USB adapter, since the Pi itself has no 2.1mm x 5.5mm jack. The 5V 5A rating exceeds the requirement of current Raspberry Pi models, so it leaves plenty of margin for attached peripherals.

Is this a wall-mount or desktop supply?

Wall-mount. The SW-55A plugs directly into an AC outlet with an attached output cable, with no separate in-line brick.

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What an INCREDIBLE deal, what service!!! I'm be buying more!

I bought the Variac/isolation transformer combo. FOR STARTERS: NOBODY ELSE MAKES THIS COMBO with a genuine isolation transformer. And that fact that it's $200 out the door is insanity. My only advice with the unit would be to double check the voltage display against a multimeter; I find my display to be about 5V lower than the actual output and adjusted accordingly.

This item was packaged more securely than a nuclear warhead. Seriously, the packing job is a masterclass in transportation and logistical safeguards.

In short--I rarely leave reviews. I felt I HAD to for this product. If you're not sure because it's a newer item/company, don't worry. They are LEGIT and they are INCREDIBLE.
One more side note--customer service response is insanely fast also. I emailed a question on a SUNDAY EVENING and got an answer.

GREAT, domestically-owned small business I will support again.

Dan-Owner, HiFi Hopes LLC

finge\thumb switch

Connected w/ extension ... beats heck outta
that * plug~it~in & unplug * device on || off

I like it

DC Barrel Plug Adapter, Female 2.1mm x 5.5mm to Male 3.5mm Mono, 18 AWG | RC-X3.5-C1

Great service and communication

Got my power supply on time and it’s a great deal!

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5V 5A AC-DC Power Supply - 2.1mm x 5.5mm Center Positive | SW-55A