External power supply device and power supply method thereof applied to incremental encoder

The invention provides an external power supply device and a power supply method thereof applied to an incremental encoder. The external power supply device is externally connected to an incremental encoder and a power supply module, and comprises a detection assembly, a control assembly and a power supply assembly. When the detection assembly detects that the power supply module interrupts main power supply, the control assembly controls the power supply assembly to supply standby power to the incremental encoder, so that the incremental encoder is still in a working state when the power supply module interrupts main power supply, and position information is calculated and output through the control assembly. 本发明提供一种应用于增量型编码器的外接供电装置及其供电方法。外接供电装置用以外接于一增量型编码器与一电源供应模块，并包含一检测组件、一控制组件与一供电组件。检测组件检测出电源供应模块中断供应主电力时，控制组件便控制供电组件供应一备用电力至增量型编码器，藉以使得增量型编码器在电源供应模块中断供应主电力时，仍然处于一工作状态，并且通过控制组件计算并输出有一位置信息。