| 摘要 |
PURPOSE:To stabilize a power amplifier element stably for a long time and to attain also unmanned motion by providing the titled device with a negative feedback circuit for holding an optimum output value determined by a control circuit stably. CONSTITUTION:A CPU body 14 varies a reference voltage generator 4 while monitoring the output of a detector 5' to search the range of stable operation voltage of a load 9 and sets up a reference voltage 4 to the stop voltage. When the state of the detector 5' is included within a certain range, a normal negative feedback loop constituted of a power amplifier element 1, a voltage detector 2 and a differential amplifier 3 acts as a stabilized power supply having a quick response speed. At the time of overload state due to the secular change of the load 9 or sudden change of input power supply which can not be followed by the negative feedback loop, the CPU body 14 drives an I/O port 12 and a driving switch 8 to open a switch 6 once, so that the device and the load 9 are protected from the overload state and the device is automatically restarted by using the preceding output value as the initial value. |
