I have a power adapter for a projector: http://www.aaxatech.com/products/p300_pico_projector.htm

It's spec'ed at 12.0V 3.0A. The cable is 2m and twin 20AWG. It also has a barrel connector 4mm OD, 1.5mm ID and 9mm long.

I cannot find an extension cable or matching adapter with a longer cable.

I need to extend the cable to 5m. Is it best to splice 3m 20AWG in? Or trim the existing cable to the max and splice a ticker 5m cable in?

I worried about voltage drop, damaging the project or adapter. Should I have a concern? What's the best fix? Recommended AWG and length?

Obviously I want to extend the adapter output. I want to have a nice finish and avoid having a mains extension.


1 Answer 1


5m of 20AWG is going to be on the order of 150mR. The potential being supplied will have to take into account the drop on both legs because the regulation point is in the head of the supply (no kelvin connection). So, at max current, drop is 3*2*.15=0.9V. Whether this works for your application is up to you.

I would splice it somewhere in the middle to make soldering easier. Use shrink wrap to protect the junctions and hold the discrete wires together. There is no benefit to replacing the entire 5m. It's still two splices.

  • \$\begingroup\$ Would you splice in matching 20AWG or something thicker? Is there a benefit? \$\endgroup\$
    – Simon
    Jan 24, 2017 at 14:18
  • \$\begingroup\$ Thicker wire is less resistive. Less drop. However, it's also more expensive and can be less flexible depending upon how far you go. \$\endgroup\$
    – M D
    Jan 24, 2017 at 14:22

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