| 摘要 |
PURPOSE:To form the overload circuit of quick response, by full-wave-rectifying load current via an absolute value circuit, and by using the current for the input of the overload circuit. CONSTITUTION:Motor current IM is converted to voltage via a resistor 2, and the input to an OP amplifier 4 is provided. When the input voltage is of a positive value Vs, then current as shown in arrow heads flows, and the output voltage V2 of an OP amplifier 9 is as shown in an equation I. Besides, when the input voltage is of a negative value -Vs, then diodes 5, 7 are turned non- conductive, and so the output voltage V2 of the OP amplifier 9 is as shown in an equation II. Accordingly, if the value of each resistance is selected to satisfy an equation III, the full-wave rectification of a regulated positive or negative peak is obtained. The input of this signal to a discriminating circuit 17 is provided, and is set to be output signal. |
