5 Volt POE
Most Access points use a 5 volt power supply. To remove the loss from the long runs up towers ect we need to build a regulated 5 volt source. Usually you start with an unregulated power supply ranging from 9 volts to 24 volts DC. To make a 5 volt power supply, we use a LM7805 voltage regulator . The LM7805 is shown below.
The LM7805 is simple to use. You simply connect the positive lead of your unregulated DC power supply (anything from 9VDC to 24VDC) to the Input pin, connect the negative lead to the Common pin and then when you turn on the power, you get a 5 volt supply from the Output pin.
You will also need to add a 1uf capacitor to the input/output sides of the LM7805
Now you are readdy to mount the POE on to a heatsink, and hook it up to the cat5 cable