| 摘要 |
PURPOSE:To make a device small-size and to protect the power supply circuit from an excessive input voltage, by inputting the rectified output voltage to a three- terminal regulator through a floating regulator when the induced voltage of a generating coil is large. CONSTITUTION:When the magnetic field in an electronic device is weak and the induced voltage of a generating coil 1 is small, a relay 9 is connected to a contact (a) side, and the output voltage of a rectifying circuit 2 is applied to a three-terminal regulator 7 directly, and a stabilized DC voltage is obtained as the output. When the induced voltage of the coil 1 becomes large, the voltage at a point (c) operates a floating regulator 8 to generate a constant DC voltage, which is determined by the internal resistance circuit (not shown in figure), at a point (d). Therefore, a current is flowed to the relay coil, and the relay 9 is switched to a contact (b) side. As a result, when the induced voltage of the coil 1 becomes a certain value or more, the input voltage of the regulator 7 is kept constant by the regulator 8, and the power supply circuit is protected from the excessive input voltage. |
