A motorized system that allows for calibration by a user, and that features circuit protection and detection of motor stoppage. A motorized window-blind system is an example of such a system and is disclosed herein. In particular, a circuit is featured that comprises a TRIAC, or “triode for alternating current,” and TVS diodes, or “transient-voltage-suppression diodes,” providing voltage protection to various types of motor-related electronic components. A controller is disclosed that features measurement of voltage that is induced on a secondary winding of a motor, in order to detect certain events that occur during the operation of the motor. A calibration method is also disclosed that can account for one or both of the protection circuit and event-detecting controller. The calibration method accounts for human interaction and, in doing so, is intended toward making a calibration process of a motorized household system less prone to human error.