Saturday, December 06, 2008


The digial clock works!

There really wasn't much that needed to be done. There were a few lose connections on the lamps, but none needed replacing. The two pin mains power connector and dual fuses were replaced with a single fuse and 3 core flex. But it was running slow, this was fixed by cleaning out the gearbox with contact cleaner and replacing the oil.

From Uniselector Clock

The first video shows how the calendar mechanism advances and resets. The whole mechanism is driven by a single large solenoid that is activated every 12 hours.

From Uniselector Clock

The second video shows the time being set. The rotary switches on the control panel are turned to the correct time and the "reset" switch lifted. The time then advances, as show by the lamps, and stops at the required minutes. The hours keep advancing until the right hour is reached and the switch released.
div>Follow this link for more pictures and information on the clock.

Wednesday, December 03, 2008

Who needs a nixie clock?

Quite possibly built in the late 1930s here's the electro-mechanical digital clock I've just acquired.

It doesn't have a digital display, i.e. one with digits, instead it has 12 lamps for the hours, five for the tens of minutes, and another 10 for the minutes.  The lamps are switched by telephone exchange type uniselectors.  There are rotary switches on the side to set the alarm.

The calendar part is entirely mechanical, but it has a cam on the month wheel to set the number of days in each month.

I'd love to know if anyone has ever seen this clock or a similar one before, where it was used, who made it, or anything else.

Over the weekend I'll see if I can get it working.


Some nixie clocks have used Strowger (uniselector) switches.  See the gallery here (search for the Tomlin clock).    
Digital (display) clocks did exist in the 1930s - see