January 6, 2003
January 6, 2003
Recently, building the nixie-tube clock seems to be now in fashion so that I report my nixie-tube clock, too.
About 8 years ago, there ware some projects to build the nixie-tube clock in a SIG of PC-VAN, I also built a nixie-tube clock at that time. The clock is working for approx. 70,000 hours. (Nov 20, 2018: 200,000 hours elapsed and it is still working fine.)
Because of the nixie-tube is a gas tube, it requires relatively high-voltage supply. Judging from archives, from 180 to 300 volts are used for supply voltage. In this project, 270 volts from rectified 100V line voltage directly is used. It is very simple but whole of the circuit is not insurated from the power line, never touch any part of the circuit.
There was a 74141 nixie driver (4bit to 10decoder + driver) in the TTL family. Sorry the 74141 is obsolated device now, it is very hard to obtain it. For new design, high voltage transister at least 300 volts for TV circuit is suitable for the nixie-tube driver.
Fortunately, I could obtain it 8 years ago. I used four 74141s for this project. The maximum output voltage of the 74141 is only 60 volts so that the driver breaks down and some cathodes will be lit when all outputs are shut off. It may be used without zero suppressing. I blanked the nixie-tube by tieing anode to grownd with transister.
The clock controller is a TMP47P242VN. It is TLCS-47 4 bit microcontroller family from Toshiba. For new design, PIC, AVR or any other microcontroller should be used instead.
This is a nixie-tube CD71 manufactured by Hitachi. It was sold for 50 yens at Nipponbasi electric town in Osaka.
The nixie-tube is one of the display devices, it is using its cathode glow. Therefore it is a kind of neon lamp. Its ten cathodes are formed into shape of each numerical character and anode surrounds the cathodes like a cage.
The nixie-tube is obsolated device so that it is not used for new design except for hobby use. However many flat panel displays using same theory of the nixie-tube have being used for industrial use.
This is a vacuum fluorescent numeral display tube (VFD). It is a kind of electron tube, not the gas tube like nixie-tube. The tube type VFDs have been obsolated, but this is also used for various home electronics and car audio as flat panel display. I built a frequency counter with the tube type VFDs ten several years ago :-)
Dot-matrix VFD. What do you wish to build with this?
This is a filament numeral display that light color can be selected with a color filter. It seems being used for instruments panel of airplanes. There are various shapes such as bar-graph and roll-gauge.
