The TP-DCDC-1218 DC to DC converters offered by Tycon Power Systems is a low cost and high-reliability solution for those requiring 18VDC Power Over Ethernet voltage from a 12 or 24V battery system.
They have an integrated PoE injector to apply the regulated 18VDC to the CAT5 Ethernet cable. The input voltage must be between 9VDC and 36VDC.
They accept data-in to a shielded RJ45 Jack and provide data-out and PoE power on the shielded RJ45 output jack.
They work by supplying power on the unused Ethernet pins 4,5(V+) and 7,8(V-).
They have various protections for surge, short circuit, and overload. The units have a power output of 18W.