| 摘要 |
PURPOSE: To provide an auxiliary power-supply system, for an encoder, in which a separate power supply is arranged and installed on the side of the encoder, in which a power-supply voltage from a servo system is detected and whose supply to the encoder by the separate power supply can be turned on and off. CONSTITUTION: An integrated circuit 41 detects whether the voltage of a DC power supply to be supplied to an encoder 20 from a servo system 10 arranged at the outside of the encoder has reached a threshold value or not, and it drives a transistor 44 via an inverter 42. The transistor 44 supplies a DC auxiliary power supply 30 to the encoder 20 when the voltage of the DC power supply does not reach the threshold value, and it stops the supply of the DC auxiliary voltage 30 to the encoder 20 when the integrated circuit 41 detects that the voltage of the DC power supply has reached the threshold value. Consequently, a power supply at a desired voltage can be supplied to the encoder 20 so as to be changed over automatically. |
