| 摘要 |
In a phase control method, an output power command value is selected from a plurality of selectable command values of triggering angle for a switching unit 5, such as 0%, 1%, 2%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%. The output power command value is selected according to an input power command value received from a controller in a higher level equipment 1, (such as a programmable logic controller or a personal computer) and an accumulated value of an output error. If the input power command value is different from one of the selectable values, an output error is generated. The error accumulates and when it passes a threshold a different selectable value will be used. This allows an enhanced resolution phase control method without using an expensive circuit and is particularly suited to heater circuits. |
