Ever since I build my first nixie clock using old 74141 drivers that aren’t produced anymore, I’ve wanted to build a new one using a more modern design. A lot of people design Nixie clocks with multiplexers and high voltage transistor arrays but these introduce a complexity of their own: […]
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The H-Bridge I built was originally too slow. I perfected it using smaller pull up/down resistors and tuning the transistor choice further, and it’s now giving very good performances. On this matter I highly recommend the Art of Electronics’ chapter on bipolar transistors under “2.2.2 Switching circuit examples” which explains […]
In my previous series about VFD filament driver, I built a power supply based on a few operational amplifiers and a transistors. I actually implemented this design in a fully fledged PCB: However, the method used is not perfect. I can still see some biasing issues proper to the […]
Final result, driving a IV-25 VFD tube! If you haven’t yet, please read the part 1 and part 2 of building a VFD filament driver! The board PCB came back from Osh Park within 2 weeks, and I quickly put it together after getting genuine LP2985 voltage regulators (previous […]
In my previous post, I showed how to build a square wave floating above ground using an operational amplifier. I originally did my test at 5 Khz, which worked quite well but gave a nasty humming sound. The signal must therefore be above the hearing range; and I have settled […]
For my next project I would like to do a big VFD display using Russian IV-25 tubes. This has lead me to read a lot about these tubes and their notorious filaments. Long story short: they are very fiddly and require a low AC voltage which is quite hard to […]