| 摘要 |
PURPOSE:To obtain voltage and current detection outputs of good linearity by converting a detection signal to a series transmission signal corresponding to its level and insulating this signal to transmit it to a low potential-side detecting circuit. CONSTITUTION:The output of a DC power source 1 is converted to an AC by an inverter circuit 3 and is fed to a load motor 2 to drive it. At this time, a main circuit current is detected by a current detecting resistance 4 and is converted to a DC signal through a rectifying stack 12 and is given to a signal detecting circuit 7. A main circuit voltage is extracted through voltage dividing resistances 5 and 6 and is given to the signal detecting circuit 7. The signal detecting circuit 7 is provided with signal detecting circuits for voltage and current, and each detection output obtained from the main circuit is inputted to an input terminal 16a or 16b of the corresponding signal detecting circuit. Detection signals are compared with detection level setting signals, and results are outputted to output terminals.
|
