Information acquisition device and information acquisition method for pulsating voltage

An information acquisition device for a pulsating voltage, comprising:

• a signal isolation circuit, utilized for receiving a switch-controlling voltage of a motor driver, and outputting a logic voltage based on the switch-controlling voltage of the motor driver;
• and
• a signal processing module, electrically connected to the signal isolation circuit;
• wherein when the signal processing module receives the logic voltage from the signal isolation circuit, the signal processing module starts a counter, and determines whether a rising edge or a falling edge is present in the logic voltage;
• wherein when the signal processing module determines that the rising edge is present in the logic voltage for a first time, the signal processing module stores a value of the counter as a first counter value;
• wherein when the signal processing module determines that the falling edge is present in the logic voltage for a first time, the signal processing module stores the value of the counter as a second counter value, then resets the counter and starts the counter again;
• wherein when the signal processing module determines that the rising edge is present in the logic voltage for a second time, the signal processing module stores the value of the counter as a third counter value;
• wherein the signal processing module then calculates a voltage duty cycle of a motor-switching period based on the first counter value, the second counter value, and the third counter value.