| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power control system for avoiding that power supplied to an electric furnace becomes extreme power such as 0% or 100% and preventing damage of a component member in the electric furnace even if an open-circuit fault and a short-circuit fault occur in a detection signal of a temperature sensor. <P>SOLUTION: A temperature sensor 11 outputs a temperature detection signal 13 of an electric furnace 9 to a program controller 3. The program controller 3 outputs a control command value 0 to 100% based on a control target temperature value and the temperature detection signal 13. A converter 21 converts the control command value 0 to 100% into -100 to 100%. A voltage divider 23 divides -100 to 100% at a desired division ratio, and outputs a control proportional value of -30 to +30%, for example. A series connection circuit 27 generates 20 to 80% of a synthesized command value obtained by adding a prescribed command value which a base signal setting unit 25 outputs with the control proportional value. A converter 29 converts the synthesized command value into a control signal adapted to an AC power regulator 7. <P>COPYRIGHT: (C)2012,JPO&INPIT |
