VFD clock "Thomas"

Please note that this page is work in progress. I will add photos and more information within the next days. In the mean time you can find some more infos and photos in the Tube Clock database. If you are interested in one of these clocks please get in contact with me soon as I have built only a very small series of these clocks.


Model "Thomas" is a VFD clock kit based on the nice (but quite rare) DT1704C and the IV-15 tubes. Compared to modern VFD tubes like the Russian IV-11 or similar types they have a very special look due to the missing gate and back plate. For brightness control a CdS LDR, the ORP-52, is used which also comes in a glass tube.

The PCB is a modern four layer SMD equipped design, only push buttons, connectors, test pins, tube sockets and the battery clips are through hole parts.

The case is made of wood and anodized aluminium and has a timelessly and elegant design. The top shell is carpentary work made of wood (black MDF and beech tree), the bottom and back plates are made of anodized aluminium. The back plate also is has an under-eloxal printing and is fully anodized (including the edges) in a champaign colour matching the beech tree stain.

The clock is built around a modern 32bit ARM controller (STM32F072) which has quite a lot of peripherals so that some interfaces could be implemented normally not found in VFD or nixie clocks. The controller and tubes are powered by high efficiency buck and boost converters with high switching frequencies so that the power supply is inaudible and the clock can be powered by a regular USB downstream port. Anyway, a wide range Blackberry power supply with an EU clip (I do not get other clips over here but they can be found e. g. on eBay) is available as an option.

Although the DT1704 are 7 segment tubes the clock can display text and implements a hierarchical menu system for configuration. The clock has four keys for navigation. This makes it possible to easily operate the clock without the use of the manual.

You can find more pictures of the clock in the picture gallery.



You can find the manuals and schematics for the clock in my cloud storage.

Operating Voltage5V +/-10%
Operating Current500mA max.
Backup Battery2xAAA cell
USBPower supply and USB 2.0 for configuration and firmware updates
Radio/AlarmMini-DIN 8 connector for DCF-77 receiver and alarm output (pin compatible with IN-18 "Blue Dream" connector)
LocoNet readyModel railroad bus system, supports fast clock as a plain slave clock
XPressNetModel railroad bus system, supports OpenDCC fast clock extension

Order information

The clocks were produced in a very small quantity (10 pieces) due to the rareness of some of the components, special options like gold sockets or travelling adapter are available in even lower quantities. The clock kit is available as soldering kit (through hole parts, all SMDs are fitted) and in some countries also as "easy peasy" kit (in the latter variant the PCB is completely soldered and tested).

Pricing information:

PCB (standard sockets), only sold together with a case kitsold out
PCB (gold sockets), only sold together with a case kitsold out
Case kitsold out
Selected tubes kit (DT1704C, IV-15, ORP-52)sold out
Blackberry power supply with Mini USB and EU clipsold out
Travelling adapter EU to USsold out

The PCB and case kits are only sold together, they had been manufactured in matching quantities and the case is very special due to the selection of LDR and interfaces. The kit does not include the batteries.

I will ship only fully insured, either by DHL which is the cheaper option or by UPS, but I reserve the right to exclude certain countries from DHL shipping.

For preorders please send me an email and put UCLK as a keyword into the subject because I most likely will need to filter spam.