Controlled regulation of power output of induction heater - uses a microprocessor counting the passing of billets to a forge and monitoring billet temp.

摘要

The induction heater raises steel billets to the temperature required for forging and has the induction coil wound in separate series connected groups with a short circuiting switch over selected coil sections to permit reduction of the power input to the billet if there is a possibility of its overheating. The steel billets are pushed through the heating coils by a hydraulic ram. The coils are in the resonant circuits of an inverter or oscillator generating power at the required frequency. A microprocessor monitors billet temperature, using an optical pyrometer, and counts the billets passing to the forge. By storing the time that each billet has been in the heater, the micro processor decides whether to bridge one of the windings thus reducing power input to prevent billet overheating, and also adjusts the heater power to match the rhythm of the forge.