| 摘要 |
The chopping power controller reduces switching error due to the noise in the current detected signal. The chopping power controller includes a switching member (18a) for supplying power to an electric load (1a) and a current sensor (2) for detecting electric current flowing through the electric load (1a). The detected electric current is compared by a comparator (16a, 30a) to a target value. The output from the comparator is supplied to a filter (23) for outputting identical signal (k) as the comparator (16a, 30a) after the comparator (16a, 30a) keeps the same level signal for a period of time. The switching member (18a) is turned off when the detected electric current continuously exceeds the target value for the period of time set at the filter (23). The filter (23) may removes the noise which has a shorter period than that of the filter (23). In other words, the filter (23) removes high frequency noise from the comparator (16a, 30a) in order to turn off the switching member (18a) accurately. Therefore, less switching error is generated due to high frequency noise. |
