5V power outlet from USB charger - Arduino Projects PSU

This is a very simple concept, it's basically a set of 4mm terminals wired to the end of a USB lead.

I had a bag of these cheap 4mm sockets http://www.aliexpress.com/item/50pcs-4mm-Banana-Panel-Socket-Test-Probe-Binding-Post-Nut-Plug-Jack-Connector/32563995312.html?spm=2114.13010608.0.72.OLMwwy knocking around, and I have a 4 amp USB wall charger. This thing basically provides the interface from USB power to 4mm sockets for banana plugs.

Assembly is hopefully self explanatory... Just wire