Which connectors does COB LED Power Injection Cable DC 5.5x2.1mm Male to use?

One end is DC barrel plug 5.5x2.1mm, center positive and the other end is Stripped and tinned bare wire, 2 core.

COB LED Power Injection Cable, DC 5.5x2.1mm to Tinned Leads

Q: What conductor does COB LED Power Injection Cable DC 5.5x2.1mm Male to use?

0.5 mm2 / 20 AWG, or 0.75 mm2 / 18 AWG.

Last updated: 13 September 2026

Overview

An led power injection cable feeds a strip somewhere in the middle of the run instead of only at one end. Flexible strip is built on a thin copper track with real resistance, so a long run fed from a single point dims toward the far end and, past a certain length, shifts color on a white COB strip. Injecting power at additional points means no single section of track carries the current of the whole run. This lead takes a 5.5×2.1mm supply to two tinned tails that solder straight to the strip pads.

Key Specifications

Connector A	DC barrel plug 5.5×2.1mm, center positive
Connector B	Stripped and tinned bare wire, 2 core
Conductor options	0.5 mm2 / 20 AWG, or 0.75 mm2 / 18 AWG
Construction	Two-core parallel, red and black
Lengths	3 m / 5 m
Voltage	For 12 V and 24 V strip systems
Options	Solder-type 5.5×2.1mm socket, JST SM connector version
Applications	COB and SMD strip injection, cabinet and display lighting, signage
Polarity	Red positive, black negative, marked at the plug
Termination	Tails stripped and tinned, ready to solder or clamp

Why one-end feed dims, and where

The mechanism is straightforward: current flowing along the strip track produces a voltage drop proportional to the length it travels and the current it carries. On a 12 V COB strip the effect starts to be visible on a white setting somewhere past five meters fed from one end, and it gets worse from there. On 24 V strip the same wattage is carried at half the current, so the drop is lower and the usable single-feed run is longer. The fix is never a bigger power supply – the supply is not the problem, the track is.

Feed arrangement	Track carrying full current	What you see	What to do
Single end feed	The whole run	Far end dimmer; visible past roughly 5 m on 12 V COB	Add an injection point
Both ends fed	Half the run, from each end	Even brightness, mild dip at the middle	Enough for most cabinet runs
Ends plus mid injection	A quarter of the run	No visible gradient	Use for long architectural runs
Injection every 5 m	5 m at most	Uniform across the whole run	Long corridors, signage, coves

The distances above are rules of thumb for 12 V strip, not a substitute for a calculation. The numbers that matter are the resistance per meter and the current per meter on your strip datasheet; send them and we will size the injection spacing to them.

Sizing the injection lead

The lead is sized by the current it has to carry and the distance it has to carry it, not by the length of the strip. Undersizing an injection lead reintroduces exactly the drop it was meant to remove, which is why the two builds below exist.

Build	Suits	Notes
0.5 mm2 / 20 AWG	Short parallel leads up to about 3 m	Common choice where the driver sits close to the run
0.75 mm2 / 18 AWG	Longer leads or higher current	Use when the supply is remote or several strips share one feed

Two-core parallel construction

The lead is a flat two-core cable rather than a round pair. That is deliberate: it sits flat against the mounting surface and follows the strip profile inside an aluminum channel or along a cabinet edge, where a round cable would stand proud and shadow the light. The tails are stripped and tinned, so they solder directly to the strip pads with no further preparation, and the tinned ends do not fray when pushed into a lever connector.

Polarity, fusing and equal lengths

Observe polarity at every injection point. Reversing one lead back-feeds the section between two points.
Where a run has more than two injection points, fuse each lead at the supply rather than relying on the driver alone.
Keep parallel leads from one supply the same length, so each section of strip sees the same voltage.
Do not join injection leads end to end. Order the single length that reaches.

Where several strips hang off one driver, a distribution point is tidier than a nest of adaptors – see the 8-way fused DC splitter cable for that job.

Termination options

The standard build ends in a 5.5×2.1mm plug for a bench supply or a driver with a barrel output. Where the injector has to be fed from a screw terminal or a distribution block, the plug can be replaced with a solder-type 5.5×2.1mm socket, or the lead can be supplied bare at both ends. A JST SM version is available for controllers and drivers in that connector family, and we build to the connector you name rather than assuming one.

Typical applications for this led power injection cable

COB strip in aluminum channel under kitchen cabinets and shelving
Display and retail lighting where a visible gradient is not acceptable
Signage and light boxes fed from a remote driver
Long cove and corridor runs off one supply
SMD strip runs extended with an IP65 waterproof DC 5521 extension
Exhibition and booth builds that get packed and rebuilt repeatedly

How to specify your build

Strip voltage and current per meter from the datasheet.
Run length and how many injection points you plan.
Conductor – 20 AWG or 18 AWG, or let us size it from the above.
Supply end – 5.5×2.1mm plug, socket, bare ends or JST SM.
Lead length, and whether the leads must be matched.
Jacket color – black or white to suit the channel.
Quantity, sample or production.

Workmanship and testing

Workmanship follows IPC/WHMA-A-620 Class 3 and the line runs under ISO 9001. Conductors from 32 to 12 AWG are in range. Continuity and pinout are verified on 100% of units before packing; if you specify an ingress rating, seal checking on the batch can be quoted.

Custom builds and ordering

A prototype lot of 5 pcs ships in 3 working days; series orders start at 500 pcs and ship 14 working days after sample approval. We hold 100 sets of mold tooling in house, so a standard body needs no tooling time and a new one adds about 10 working days. OEM and ODM builds go out under your part number and label, with material certificates and first-article reports on request.

Related DC assemblies

Full range: DC plug power cable assemblies.

Frequently Asked Questions

How many injection points do I need?

Work from the resistance and current per meter on your strip datasheet. As a starting rule, inject every 5 m on 12 V strip and check the far end with the run at full brightness before you close it up.