Safety switch

A method of safely switching a state of an electrical apparatus, the method comprising:

• starting with an actuator in a first actuator position and a blocker being adjacent to the actuator in a first blocker position;
• first, moving the blocker from the first blocker position to a second blocker position that is distal from the actuator;
• second, moving the actuator from the first actuator position to a second actuator position with is the same as the first blocker position;
• whereas moving of the actuator from the first actuator position to the second actuator position is precluded without first moving the blocker from the first blocker position to the second blocker position;
• and
• making the actuator and the blocker of a material that permits the passing of light through the actuator and the blocker.

A safety switch comprising:

• an actuator, the actuator physically interfaced to a permanent magnet, the actuator having a first possible actuator position and a second possible actuator position defined by a first detent and a second detent respectfully located along a guide which movably supports the actuator;
• a blocker, the blocker having a first possible blocker position and a second possible blocker position, the first possible blocker position overlapping with the second possible actuator position defined by the second detent and a third detent respectfully located along the guide which movably supports the blocker;
• and
• a magnetic sensor, the magnetic sensor situated such that the magnetic sensor generates a first electrical signal when the actuator is in the first possible actuator position in which the permanent magnet is in proximity of the magnetic sensor and the magnetic sensor generates a second electrical signal when the actuator is in the second possible actuator position in which the permanent magnet is distal from the magnetic sensor;
• whereas when the actuator is in the first possible actuator position and the blocker is in the first possible blocker position, the blocker prevents movement of the actuator from the first possible actuator position to the second possible actuator position without first moving the blocker from the first possible blocker position to the second possible blocker position.