| 摘要 |
PURPOSE:To shorten an arrival time to the desired frequency by controlling the variation in a command output to an inverter device when a load current is the prescribed level or higher, thereby preventing a control from stalling. CONSTITUTION:An inverter device 3 is controlled by a command output signal I0, and this output is driven by a motor 4. This control circuit has the first comparator 1, a voltage divider PD, an integrator 2, the second comparator 5, and a switch 6 of a field effect transistor. Thus, the comparator 1 compares a command input signal Ic with a command output signal I0, inputs its output through the divider PD to the integrator 2 to obtain the signal I0. In this case, the comparator 5 compares the current level IL of the motor 4 with a reference level signal Ir, and closes the switch 6 by the output signal 5a when the signal IL corresponding to the frequency of the inverter 3 exceeds the signal Ir. Thus, the input voltage of the integrator 2 drops, suppresses the output signal I0 to prevent the motor 4 from stalling. |
