| 摘要 |
PURPOSE:To prevent the breakdown of a load by having a pulse duration computing means which computes the maximum pulse duration to the rated power of the load and a pulse duration limiting means which turns on and off a switching means. CONSTITUTION:The maximum pulse duration to the rated power of a load 4 is computed by a pulse duration computing means 5 according to an output- level set signal. And when the duration of a pulse signal inputted from the outside is shorter than the maximum pulse duration, the signal is given direct to a switching means 3, while with the duration of a pulse signal longer than the maximum pulse duration, an output signal is limited to the maximum pulse duration by a pulse duration limiting means 6 for being given to the switching means 3. Even if a pulse signal becomes such a kind that it is continuously turned on or turned off due to abnormality in an outside pulse signal generating source for resulting in supply of such power as to exceed the rated power of the load 4, the load 4 is accordingly prevented from supply of any overlarge power. The breakdown of the load 4 can be thus prevented. |
