Clock with IN14 (Russian) Nixies

This is a nice clock, with a compact design, thanks mainly to the large number of surface mounted (SMD) components. This clock uses a 12VDC/300mA adapter. PCB dimensions are 210mm x 75mm x 72mm (WxHxD). The case is made from precision cut top and bottom plates sandwiching a wooden frame. Further details from Franks website.

Mouse over the image below...

The clock looks really nice in the dark, and is really restful to watch, thanks to the softwares "digit fading effect". Note the '2' digit is an inverted '5' (or visa versa?), a characteristic of the Russian IN14 Nixie tubes. The tubes are 55mm high, and the digits are 18mm. With the original design, there was some 'ghosting' visible when the voltage supply was set too high (eg, which might occur in order to increase the brightness), an Anit-ghosting modification fixed this phenomena, and also improved the digit sharpness.

I fitted some blue high intensity LEDs under the Nixies for visual effect! After some experimentation, the diodes were each connected between +12volts and GND with a 470R series resistor.

In the PCB picture below, the PIC microcontroller is on the left. The large blue button capacitor provides power for the real-time clock (RTC) back-up option, which keeps time when power is lost. The black cable (left) connects to a DCF77 receiver to automatically set the clock from the Atomic Time transmitter Frankfurt, Germany.

The electrolytic capacitors and inductor (right) are part of the high voltage (HV) generator circuit which converts 12V into a regulated 142V supply for the nixie tubes.

PCB underside
PCB underside

The software controlled digit "fading effect" can be seen below. The 7 (seconds) is fading out as the 8 is fading in. Its very restful to watch. I think the blue glow from the LED's gives a nice effect too.

Close-up, some say it looks like a gas stove!
6 tube in14 clock with blue LED glow

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