out for a certain period of time after the power is turned on and the switch signal s 1 1 is output the short circuit abnormality determination unit 20 of the cpu 17 is configured to carry out the short circuit abnormality determination process based on the respective phase voltages v a to v c output from the angle detection signal reception block 15 while the abnormality determination controller 19 is outputting the switch signal s 1 1 a short circuit abnormality determination result is configured to be output to the outside so that a given abnormality process should be carried out for example the drive control of the motor 1 can be stopped as an abnormality process next a short circuit abnormality determination process to be carried out by the cpu 17 will be described specifically fig3 is a flowchart illustrative of the short circuit abnormal determination procedure the short circuit abnormality determination process starts when the power is turned on firstly at step s 1 the abnormality determination controller 19 outputs the switch signal s 1 1 to the change over switch 13 accordingly the change over switch 13 is in a state indicated by a broken line of fig2 and the short circuit abnormality detection signal dc voltage generated by the short circuit abnormality detection signal generation block 12 is applied to the three phase resolver 2 next at step s 2 the short circuit abnormality determination unit 20 acquires the voltages of the.