Spencer Bliven

Our house came with this clock in the kitchen. The clock runs several hours fast per day, making it completely useless for telling time. So of course, I took it apart and messed with it. I was hoping to find some timing adjustment inside, but the clock must have cost around 5¢ to make, leaving no room for such niceties. In the end I just figured out the gear assemblage and put it back together. Here’s the insides: The motor on the left is rather clever. There’s an IC on the back containing the piezo. Every second, this reverses the polarity of the attached coil, causing a magnet to flip over. This makes the ‘click’ sound in electric clocks. Unfortunately, I can’t do anything to fix a faulty IC circuit.

Gear	Ratio to previous	time/revolution
1	-	2 sec
2	4	8 sec
3	15/2	60 sec
4	15/2	15/2 min
5	8	60 min
6	3	3 hr
7	4	12 hr

One thing I was unable to figure out is the mechanism keeping the magnet flipping in a consistent direction. So as a prank/experiment I reversed the leads on the motor coil. We’ll see how long it takes my roommates to figure out that the broken clock now runs backwards.