| 摘要 |
PURPOSE:To shift a table at a high speed and to reduce the ripples in a low- speed shift mode by attaining the switch between 1/4 and 1/8 timing pulses. CONSTITUTION:A table shift device of a robot device, etc. obtains sine wave signals 9a and 10a having phases different by 90 deg. from each other from two sensors with the shift of a scale fixed to the table and supplies them to a controller. This controller consists of a waveform shaping circuit 16, a timing pulse generator 17 which delivers a timing pulse 17a with four types of rectangular waves 12a-15a, a control circuit 18 and a buffer circuit 19 and energizes a voice coil 3 via a D/A converter 20 and a constant current amplifier circuit 21. Here a switch circuit 22 is put into the circuits of rectangular waves 14a and 15a, and the circuit 22 is controlled by the control signal of the circuit 18. The signal supplied from the circuit 17 is turned into a 1/4 pulse with an OFF mode of the circuit 22 and then into a 1/8 pulse with an ON mode of the circuit 22 respectively. |
