Introduction
The clock was to sit on a bookcase with a vertical aspect. Four ZM1022 nixies (bought on Ebay) for hours and minutes. The digits would fade in and out as they change, overall brightness would be set by sensing the room illumination using an LDR. The nixies would turn off entirely if left in a quiet room but illuminate on hearing a sound sensed by a microphone.
Seconds would be indicated using a GC10B dekatron counter. The display would act in a pendulum fashion swinging once per second or take one minute to orbit entirely.
The high voltage supply for the dekatron and nixies was to use a voltage multiplier (Cockcroft-Walton). The clock would not have any facility to set the time but use a modified GPS time signal broadcast locally from a GPS receiver in the house loft on the 900 MHz licence-free band.
The box is made from thin MDF and veneered on the front (my second attempt at veneering in 35 years). The chassis inside was used to mount all of the PCBs using brackets as necessary. The electret microphone was just glued to the box and the LDR was glued to the front.
I stopped using the locally broadcast GPS signal and have moved to individual GPS receivers or more recently WiFi and NTP. The clock has bee retired but the intention is to design a new bookcase nixie clock using laser cut and engraved leather covering a laser cut wooden box. Get in touch if you are interested in Bookcase Clock 2!
Schematics and PCBs
You should look in the "/Nixie Projects/Bookcase Nixie Clock 1" folder.
Software
The software is currently awaiting a full re-write and is not available. Sorry. (This rewrite ain't going to happen, see above.)