HEATER
A heater includes a ceramic core and a metal wire secured to the ceramic core. The ceramic core includes four through holes.
1 . A heater, comprising a ceramic core and a metal wire secured to the ceramic core, wherein the ceramic core comprises four through holes.
2 . The heater of claim 1 , wherein the metal wire comprises a first part coiled into a spiral disposed in one of the four through holes, and a second part extending out of the ceramic core to form a pin.
3 . The heater of claim 2 , comprising four metal wires; wherein the four metal wires each are coiled into the spiral and are disposed in the four through holes, respectively; each metal wire comprises two pins; and the four metal wires are parallel-connected to each other.
4 . The heater of claim 3 , wherein the four through holes are cylindrical, and the four metal wires each are coiled into a cylindrical spiral.
5 . The heater of claim 4 , wherein the ceramic core is cylindrical.