What's in a Quartz Clock

having come across instructables on equatorial mounts I wondered why no one used a quartz movement as the power source I quickly realised it is because they produce very low torque. I wondered if there was anything thing that you could do to improve it so as a starting point I took one apart to see.

thankfully the designer decided a couple of moulded in clips would save messing around with glue, so it's a simple case of popping them undone and gently easing the case appart. I used a small screwdriver but I could probably of managed just with finger nails.

I missed a clip in the battery compartment and used a little too much force. Not to worry I've repaired mechanical alarm clocks before this shouldn't be a problem to resemble.

the reason a quartz movement doesn't produce much torque is that basically what you have is a small 2 pole brushless motor kicked around one pole at a time by a pulse to the windings from an encapsulated chip and a quartz crystal.

unlike a traditional mechanical clock where the gear train is mounted between 2 plates. The gear train for this quartz clock are mounted either side of a central plate sandwiched between the two halves of the case. The first thing to reinstall is the minute hand drive. This is driven by a small gear that passes through the mounting plate.

the hour hand is driven by an intermediate reduction gear and has a hollow shaft that runs on the outside of the minute hand shaft.

first the electronics need to be reinstalled in the case. The board and field coil locate on 4 pins 2 of the pins also help locate the central plate. Once the central plate is in place the front section of the case has to be supported on a hollow support.

the armature mounts on a shaft between the two poles of the field coil.

the last two gear are fitted to the central plate and linked by the second hand drive. The back of the case then clips back into position.