Multiple phase switching circuit and heat sink structure

摘要

A multiple phase electricity switching apparatus having electrical components arranged and mounted on a heat sink structure which having the same external dimensions as a conventional electromagnetic relay. The switching apparatus controls the amount of electrical energy passing therethrough and into electrical resistance heating elements thereby controlling the temperature of the molten plastic raw materials. The switching apparatus includes a pair of inverse parallel connected SCR's (silicon control rectifier), a photo coupling, and a zero cross switching circuit. The SCRs are separately mounted on and separated by a structure having two parallel members. The electronic circuit components permit the electrical power supplied to the load to be switched more frequently thereby realizing improved temperature regulation.