About the efficiency of mechanical alarms: in the 1980s. The girlfriend stood up like this: on the secretary's thrown-off cover was placed a big grandmother's alarm and soup plate, a spoonful was placed in the plate. The drizzling of the alarm clock caused the secretary’s lid to vibrate and the spoon burst on the plate. But little of that! Because of the vibration, the plate slowly but steadily slipped to the edge of the thrown cover. It was necessary to wake up, jump up and pick up the plate before it fell and broke down (for which you could get p**s from my mom).