---
product_id: 34791532
title: "3vdc -12 volt Universal AC/DC Power Adapter USB Port | 8 Reversible Polarity Positive or Negative Tips Center Tip 3v 4.5v 5v 6v 7.5v 9v 12v 1a 12w Transformer 5.5mm 2.5mm 2.1mm 3.5mm 4.0mm 5.0mm 1.7mm"
brand: "protechtrader"
price: "€ 28.86"
currency: EUR
in_stock: true
reviews_count: 13
category: "Pro Tech Trader"
url: https://www.desertcart.nl/products/34791532-3vdc-12-volt-universal-ac-dc-power-adapter-usb-port
store_origin: NL
region: Netherlands
---

# 12W max power output 8 reversible polarity tips Multi-voltage 3-12V adjustable 3vdc -12 volt Universal AC/DC Power Adapter USB Port | 8 Reversible Polarity Positive or Negative Tips Center Tip 3v 4.5v 5v 6v 7.5v 9v 12v 1a 12w Transformer 5.5mm 2.5mm 2.1mm 3.5mm 4.0mm 5.0mm 1.7mm

**Brand:** protechtrader
**Price:** € 28.86
**Availability:** ✅ In Stock

## Summary

> 🔌 Power up smarter, not harder — the only adapter your devices will ever need!

## Quick Answers

- **What is this?** 3vdc -12 volt Universal AC/DC Power Adapter USB Port | 8 Reversible Polarity Positive or Negative Tips Center Tip 3v 4.5v 5v 6v 7.5v 9v 12v 1a 12w Transformer 5.5mm 2.5mm 2.1mm 3.5mm 4.0mm 5.0mm 1.7mm by protechtrader
- **How much does it cost?** € 28.86 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.nl](https://www.desertcart.nl/products/34791532-3vdc-12-volt-universal-ac-dc-power-adapter-usb-port)

## Best For

- protechtrader enthusiasts

## Why This Product

- Trusted protechtrader brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Compact Yet Mighty:** Lightweight 2.82 oz design fits anywhere without cluttering your workspace.
- • **Certified Safety & Compliance:** UL Listed and ROHS Compliant for peace of mind powering your valuable electronics.
- • **Power Your Entire Tech Arsenal:** Supports 3V to 12V with a simple side switch for ultimate device compatibility.
- • **USB Port for On-the-Go Charging:** Built-in USB port delivers up to 1A, perfect for smartphones and tablets.
- • **Flip the Polarity, Not Your Device:** 8 reversible DC tips let you switch between center positive and negative polarity effortlessly.

## Overview

The 3vdc-12 volt Universal AC/DC Power Adapter is a versatile 12W (1A) power supply featuring adjustable voltage from 3V to 12V, 8 interchangeable reversible polarity tips, and a built-in USB port. Compatible with thousands of small electronics including tablets, routers, cameras, and more, it offers UL listing and ROHS compliance for safe, reliable use. Its compact design and polarity flexibility solve common adapter headaches, making it an essential tool for professionals managing multiple devices.

## Description

desertcart.com: 3vdc -12 volt Universal AC/DC Power Adapter USB Port | 8 Reversible Polarity Positive or Negative Tips Center Tip 3v 4.5v 5v 6v 7.5v 9v 12v 1a 12w Transformer 5.5mm 2.5mm 2.1mm 3.5mm 4.0mm 5.0mm 1.7mm : Electronics

Review: Solution for hard-to-find jack polarity, negative inner conductor - Works good. Solution for hard-to-find jack polarity, negative inner conductor. No measured power draw at no-load, measured with 0.1 VA and 0.1 watt resolution. Yay.
Review: Works great for Sony Minidisc players! - Bought this to power my Sony MZ-N505 minidisc player, 3 Volts, center positive. Works like a charm! Great value since OEM power adapters are like $80. There's a tip that fits perfectly and the voltage changer is just a potentiometer on the back, simple design. Will be buying more for other devices.

## Features

- Multi-Voltage 12 Watt (12w/1-amp) replacement switching power adapter supply compatible with 1000s of small electronic devices using requiring 3 volt, 4.5 volt, 5 volt, 6 volt, 9 volt, or 12 volt up to 1.0a or 12 watts including many Electronics, Tablets, Routers, Smart Phones, Speakers, Monitors, TVs, LCDs, Cameras & Other USB Port Charging up to 12watt 1000ma with US 120 volt Plug
- Includes 8 Interchangeable DC Tips/Plugs of the most popular sizes: 5.5mm x 2.5mm / 5.5mm x 2.1mm / 5.0mm x 2.1mm / 3.5mm x 1.35mm / 4.0mm x 1.7mm/ 2.5mm / 3.5mm / 2.5mm x 0.7mm. Please make sure your device is one of these size jacks on it for proper fit and the standard center positive polarity. New Upgraded model comes with a USB port built in
- NEW model now has REVERSIBLE DC Tip Polarization - Both Center/Inside/Middle Tip Positive (+) Outer/Outside Tip Negative (-) and Inside/Center Negative (-) Outer/Outside Positive (+) Can be Set by Removing Tip and Placing it in Opposite Position. This allows for maximum device compatibility as it can be set to operate in both center tip pos and center tip neg polarities. Please be sure to verify your device polarity, tip size and voltage before purchasing.
- Voltage is easy to change by the switch on the side of the adapter. Be sure you're using the correct VOLTAGE & POLARITY for your device before plugging it in. If you are not sure please use the "Customer Questions & Answers" section below before purchasing and provide your product brand, model, and part number if available and we will try to help verify your device's power requirements.
- UL Listed & ROHS Compliant | Input: 110v - 220v AC / Output: 3v - 12v DC - Maximum Current from DC tip is up to 2.5a or 30 watts (USB Port Limit is 1.0amps) - If your device requires less power, such as 200ma, 300ma, 400ma, 500ma, 600ma, 750ma or any other up to 2500ma through the DC barrel connectors it will work with this adapter with a matching tip and proper voltage/polarization
- Need More Wattage? Check Out Our 30W Universal Power Adapter. Message Us for More Details.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B01LBX8D58 |
| Customer Reviews | 4.4 4.4 out of 5 stars (477) |
| Date First Available | September 1, 2016 |
| Is Discontinued By Manufacturer | No |
| Item Weight | 2.82 ounces |
| Item model number | VPOW312-USB |
| Manufacturer | ProTechTrader |
| Product Dimensions | 2 x 1 x 2 inches |

## Product Details

- **Brand:** ProTechTrader
- **Color:** Black
- **Input Voltage:** 220 Volts
- **Item Weight:** 0.08 Kilograms
- **Item dimensions L x W x H:** 2 x 1 x 2 inches

## Images

![3vdc -12 volt Universal AC/DC Power Adapter USB Port | 8 Reversible Polarity Positive or Negative Tips Center Tip 3v 4.5v 5v 6v 7.5v 9v 12v 1a 12w Transformer 5.5mm 2.5mm 2.1mm 3.5mm 4.0mm 5.0mm 1.7mm - Image 1](https://m.media-amazon.com/images/I/71jUSmRdUgL.jpg)

## Questions & Answers

**Q: How do you know that you are authentic?**
A: A: If you see yourself in the mirror and you know that you're that person, and if you've been honest in your interactions with others, then that's a good definition of authentic.

**Q: I need a unit that will supply power at 6V and 1.5-2W - will this device do that or will it over-power the wattage requirement?**
A: It will work perfect at 6v 1w, 1.5w, 2w, 3w, 4w, 5w, 6w.  You can not over watt or over current a device, as a device only draws as much current as it needs from the power supply.

Watts are a measure of current output at a given voltage.   As far as current is concerned, the more the better at the supply end as a device requiring only 1.5w will only draw 1.5w of current.  Having more available does not hurt ether device at all.  This does not apply to voltage, as it is important to match voltage from the source to your device (ie you have a 6v device so set this power supply to 6v), but the current is not something you have to set.  You want to have at least the amount of current available that your device requires or more.  More is better as the device will only draw or pull as much current as it needs.  For example you device requires 6 volts and 2 watts, and lets say this power supply can produce 6 volts with up to 6 watts (this is equal to 1 amp or 1000ma).  Even though the device had up to 6 watts available current, your devices maximum current draw is 2 watts at 6 volts so it will only get 2 watts and the power supply's additional current is not used, but available if a larger current draw is ever required by the device or a new device.

Hope that made sense.  If not you can kind of think of it like horsepower in a car.   If you have 100 hp available in your car the engine (engine is like the power supply) is not always supplying the full 100 horsepower as the car load (the car load is like the devices current draw... aka load) may not require all 100 hp due to driving slowly with no passengers, but the power is still there if it is ever needed in the future.

**Q: Will this fit and work with the brother pt-d200 label maker?**
A: It should work.  You can reverse the polarity with the tips.  I am not site if the tips will fit

**Q: what is the length of the  cord?**
A: The cord is 44 inches long or just over 3-1/2 feet long.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Solution for hard-to-find jack polarity, negative inner conductor
*by F***E on December 3, 2025*

Works good. Solution for hard-to-find jack polarity, negative inner conductor. No measured power draw at no-load, measured with 0.1 VA and 0.1 watt resolution. Yay.

### ⭐⭐⭐⭐⭐ Works great for Sony Minidisc players!
*by E***N on December 3, 2025*

Bought this to power my Sony MZ-N505 minidisc player, 3 Volts, center positive. Works like a charm! Great value since OEM power adapters are like $80. There's a tip that fits perfectly and the voltage changer is just a potentiometer on the back, simple design. Will be buying more for other devices.

### ⭐⭐⭐⭐⭐ great for the price
*by K***N on November 25, 2025*

works perfectly fine thank you.

## Frequently Bought Together

- 3vdc -12 volt Universal AC/DC Power Adapter USB Port | 8 Reversible Polarity Positive or Negative Tips Center Tip 3v 4.5v 5v 6v 7.5v 9v 12v 1a 12w Transformer 5.5mm 2.5mm 2.1mm 3.5mm 4.0mm 5.0mm 1.7mm
- SoulBay [Reverse Polarity] 30W Universal AC DC Adapter Switching Power Supply Selectable Voltage with 9 Tips for 3V 4.5V 5V 6V 7.5V 9V 12V Household Electronics, 2000mA 2Amps Output Max

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*Product available on Desertcart Netherlands*
*Store origin: NL*
*Last updated: 2026-02-07*