While back home for winter break, my sister kept complaining that my brother and I needed to put down the toilet seat after using the bathroom. Instead of putting the seat down like a normal person, I decided to automate the task.
The automatic toilet seat was built from a recyled standing desk motor, 2 limit switches, an old laptop power supply, a switch, scrap aluminum sheet metal and a 3D printed coupler. The aluminum bracket is bolted under the toilet seat bolts and mounts the motor so that the motor shaft aligns with the toilet seat axis of rotation. The 3D printed coupler connects the hexagonal motor shaft hole and the toilet seat rectangular boss. The limit switches were oriented to trigger when the seat was in the up or down position. The motor was directly driven by the power supply with no motor controller (which isn't great, but it works) and the mechanical switch reversed polarity changing the direction of the motor until it hit the other limit switch cutting off power to the motor.