|This item really only makes sense in Multiplayer. You could craft it alone if you really wanted to, but what would be the point of that?|
This device has two functions. First of all, it acts like an Item-O-Mat and will sell ENERGY. To be precise, an Energy-O-Mat will work like a cable.
However, it will not allow current to pass freely. Instead, customers need to drop coins into the Energy-O-Mat, to fill up its deposit.
The Energy-O-Mat will then use this deposit and allow current to pass.
For this to work, the owner of the Energy-O-Mat needs to place a chest next to it and define (as usual) a price in the last chest slots.
The second function of the Energy-O-Mat is to activate redstone-based systems, for the rare occasion people are actually still using this outdated system.
As long as the Energy-O-Mat is allowing energy currents to pass, it will trigger redstone wires nearby.
For this sake, if you do NOT place a chest near to it, OR leave the chest empty (and thus define a price of zero), the Energy-O-Mat will allow any current to pass freely, even without being paid.
See: Crafting Guide