RELAY CLOCK

This is a digital clock I built over a period of some 8 months.  The digits are controlled by 3 ten-stage ring counters, one each for the seconds, minutes and hours.

No electronic parts have been used in any part of the display logic; all of the control functions are undertaken by small 12 volt relays and diodes.

The timing for the clock is derived from the 50Hz mains frequency so will always remain very accurate. 

I decided to build the clock in such a way as to make visible all of the component parts and their interconnecting wiring which can be viewed through the glazed front cover.

A control panel allows the user to synchronise the clock’s display to the current time by advancing each ring counter rapidly or slowly step-by-step.  A switch is also provided to change the logic of the hours display from a 12 to a 24 hour mode.

The many LEDs on all parts of the circuitry give the user an indication of the progress of the systems logic as the clock calculates the time to display. 

Many thanks to YouTuber David Skirmont for showing me what’s possible with his version of a relay clock.