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✓ Technical support from people who know the product
Choose from our full range of DC power connectors — barrel jacks, plugs and sockets in the common sizes (2.1mm, 2.5mm and 5.5 × 2.1mm) — with our own TruConnect parts held in UK stock.
DC power connectors — also called barrel or coaxial connectors — carry low-voltage DC from an adaptor or supply into equipment. We stock the full range of plugs, sockets and jacks, in cable-mount, panel-mount and PCB-mount forms, so you can find the right fit and have it on the bench tomorrow. For the wider picture, see our guide to connector types.
What sizes do DC power connectors come in?
A barrel connector is described as outer diameter × inner pin diameter, in millimetres. The sizes you'll order most often are:
5.5 × 2.1mm — the most common size for 12V equipment and adaptors.
5.5 × 2.5mm — same outer barrel, wider pin; check which your kit needs.
3.5 × 1.3mm — smaller devices and low-current supplies.
2.5 × 0.7mm and other miniature sizes for compact electronics.
Match both diameters and the barrel length, as a plug that's close but not exact will make a poor connection.
Plugs, sockets and mounting
We carry the connector whichever end you're wiring: cable-mount plugs for leads and adaptors, chassis and panel-mount sockets for equipment fronts, and PCB-mount jacks for boards. Right-angle, inline and locking versions are available where the fit needs them.
How do I choose a DC power connector?
Size — match the outer and inner diameters (for example 5.5 × 2.1mm) to your equipment.
Voltage and current rating — check the connector is rated for your supply.
Polarity — most are centre-positive, but confirm before wiring.
Mounting — cable, panel or PCB, plus right-angle or locking if needed.
Not sure which to specify? Our technical team will help you match a part, and we supply bespoke quantities when a project needs them.
TruConnect — the same spec, for less
Our own TruConnect DC connectors match the branded parts on size, rating and fit. Where a part has a branded equivalent, we show the TruConnect option beside it, so you can compare the spec and the price directly, then decide. Every part is held in UK stock and backed by technical support from people who know the products.
The most common size is 5.5mm outer diameter with a 2.1mm inner pin (written 5.5 × 2.1mm). 5.5 × 2.5mm and 3.5 × 1.3mm are also widely used. Always check both diameters and the barrel length before ordering.
How do I measure a DC power connector?
Measure the outer diameter of the barrel and the inner diameter of the centre pin in millimetres. A connector is described as outer × inner, for example 5.5 × 2.1mm. The barrel length matters too on panel-mount parts.
What is the difference between a 2.1mm and a 2.5mm DC connector?
The figure is the inner pin diameter. A 2.1mm plug pushed into a 2.5mm socket makes a loose, unreliable connection, so match the pin size as well as the 5.5mm outer diameter.
Are all DC barrel connectors the same?
No. Outer diameter, inner pin diameter and barrel length all vary between types, and polarity can differ. Match the size to your equipment and check which pin is positive before wiring.
Which way round is the polarity on a DC connector?
Most DC barrel connectors are centre-positive, meaning the inner pin is positive and the outer sleeve is negative, but not all are. Check the polarity symbol on your equipment before connecting.
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