# DC Power Adapter Barrel Jack

**Type:** Product page · **SKU:** POLOLU-1139 · **Brand:** [Pololu](https://core-electronics.com.au/brands/pololu-australia)
**Page:** https://core-electronics.com.au/dc-power-adapter-barrel-jack.html ([markdown](https://core-electronics.com.au/dc-power-adapter-barrel-jack.html.md))

This is a standard PCB-mountable barrel-type jack for DC power adapters with 2.1 mm center holes.

## Pricing

- **Price:** $2.20 (inc GST) — $2.00 AUD, exc GST
- **Quantity discounts:** 10+ $1.92 (exc GST) · 25+ $1.86 (exc GST)

## Availability & dispatch

- In stock, ships same business day if ordered before 2PM (Australia/Sydney).
- We can dispatch 6 today, and up to 200 more in 4–7 days.

## Description

This is a standard PCB-mountable barrel jack for DC power adapters with 2.1 mm center holes. This jack is compatible with Pololu's wall-adapter power supplies:

| ![](https://core-electronics.com.au/media/remote_images/0J2208.372_P7XAhH.png%3F3072213fb533812ac0216abbcc77b5c9) |
|---|
| Dimensions (in mm) for the DC power adapter barrel jack. |

The jack has three pins: pin 1 comes out of the back of the jack and is connected to the center pole, pin 2 comes out of the bottom of the jack and is connected to the side wall, and pin 3 comes out the side of the jack and is automatically switched based on whether there is anything plugged into the jack. With nothing plugged into the jack, pins 2 and 3 are shorted together; with an adapter plugged into the jack, pin 3 is disconnected. This feature makes it easy to create a system that is powered by a wall adapter when one is plugged into the jack and by a battery the remainder of the time.

For a DC jack that connects directly to a terminal block for easy connection of wires, see Pololu's [DC barrel jack to 2-pin terminal block adapter](https://core-electronics.com.au/dc-barrel-jack-to-2-pin-terminal-block-adapter.html).

## Images

- [Product image 1](https://core-electronics.com.au/media/catalog/product/d/c/dc_power_adapter_barrel_jack__pololu_1139__00.jpg)