Preventing metal oxide varistor (MOV) from releasing smoke, smell, and/or sound

A system comprising:

• an electrical component;
• a metal oxide varistor (MOV) connected in parallel to the electrical component;
• a voltage sensor to detect a voltage over the MOV and the electrical component;
• and,
• a circuit to remove power in response to the voltage sensor detecting the voltage over the MOV and the electrical component being greater than a threshold voltage for a length of time greater than a threshold length of time,
• wherein the electrical component is a capacitor, such that upon the capacitor wearing out, the voltage over the MOV and the capacitor exceeds a rated voltage of the capacitor, such that the MOV vents the capacitor to protect the capacitor, but such that the MOV begins to one or more of smoke, smell, and sound when the voltage over the capacitor exceeds the rated voltage by more than a given length of time.

A method comprising:

• providing an alternating current-to-direct current (AC-to-DC) power supply having:
• a circuit segment comprising a first capacitor and a second capacitor connected in series to receive a rectified AC voltage over the circuit segment;
• a transformer having a first coil and a second coil, the first coil connected in parallel to the circuit segment, the second coil to provide a stepped-down voltage from the rectified AC voltage, the stepped-down voltage rectified and filtered to provide a DC output voltage of the AC-to-DC power supply;
• and,
• a metal oxide varistor (MOV) connected in parallel to the first capacitor;
• providing a voltage sensor to detect a DC voltage over the MOV and the first capacitor;
• and,
• providing a circuit to remove power in response to the voltage sensor detecting the DC voltage over the MOV and the first capacitor being greater than a threshold DC voltage for a length of time greater than a threshold length of time.