Electromagnetic resistance feedback system for bicycle training device

An electrical resistance feedback system for a bicycle training device, comprising:

• a bicycle trainer frame arranged for connection with a bicycle;
• an electricity generator including a rotating object, mounted to the bicycle trainer frame;
• and
• a resistance feedback system mounted to the bicycle trainer frame, wherein the resistance feedback system comprises:
• a transmission system configured to interact with an external electronic device;
• an electromagnetic resistance generation unit, separate from the electricity generator, excitable by an electrical current to generate an electromagnetic field to induce an electromagnetic resistance force to the rotating object, wherein the electromagnetic resistance generation unit includes a drive circuit and a resistance applying device having at least one winding;
• a feedback circuit having an electromagnetic detection element mounted to the resistance applying device of the electromagnetic resistance generation unit, wherein the electromagnetic detection element is a Hall sensor and is configured to detect strength of the electromagnetic field generated by the resistance applying device;
• and
• a control unit electrically connected to the transmission system, the electromagnetic resistance generation unit, the feedback circuit, and the electricity generator;
• wherein the drive circuit is electrically connected to the electricity generator, the control unit and the resistance applying device, and is controlled, by the control unit, to adjust the strength of the electromagnetic field generated by the resistance applying device;
• wherein the control unit is configured to receive, from the electromagnetic detection element, the strength of the electromagnetic field generated by the resistance applying device and in response thereto, adjust a level of the electromagnetic resistance force generated by the electromagnetic resistance generation unit;
• wherein the control unit is further configured to control the electromagnetic resistance generation unit to generate a predetermined level of electromagnetic resistance force, the predetermined level of electromagnetic resistance force corresponding to a predetermined electromagnetic field strength;
• wherein when the electromagnetic detection element detects the strength of the electromagnetic field generated by the resistance applying device being different from the predetermined electromagnetic field strength, the control unit controls the drive circuit to adjust the strength of the electromagnetic field generated by the resistance applying device such that the strength of the electromagnetic field generated by resistance applying device matches with the predetermined electromagnetic field strength;
• and
• wherein the control unit controls the drive circuit to adjust the strength of the electromagnetic field generated by the resistance applying device, by applying a pulse width modulation signal to the drive circuit and controlling a duty cycle of the pulse width modulation signal.