I have been talking about VFDs for a long time now, mainly how to power them. I now have my PCBs for 12 IV-25 tubes ready and soldered! The big display You have to imagine this panel upright, 6 of them side by side. That will give a total area […]
Today we are reviewing the PCBs made by JLCPCB. JLCPCB is one of the bigger Shenzhen based PCB manufacturers out there. Although questionable, they claim to get over 8000 orders per day. More recently they got a lot of community support by partnering up with EasyEDA; but they also made […]
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 […]
My next project will probably feature an ESP32 and I would like to be able to re-flash it with a new firmware even when it is firmly soldered on its PCB. As as a result, I looked for USB interfaces chips and although the official ESP32 devkit uses a CP2102, […]
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 […]
I am currently designing a big VFD tube IoT thing and when creating the PCB I sent the gerber files to OshPark. They quoted back about US$180. Ouch. OshPark pricing completely breaks down once you start marking a board 4 inches / 10 cm long or above. So to China […]
Lately I have been playing a lot with the amazing esp32. It is an amazing “microcontroller” for makers, and I add quotes to “microcontroller” because really, it’s an IoT do-it-all SoC; all for the low price of about US$5. One of the main features of the esp32 is its ability […]
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 […]
This is a sour experience I wish to share with everyone. The lesson learned: do not buy ICs from Aliexpress/Banggood etc. On my VFD tube driver design, everything runs off 12V. Everything except an ATTINY13 that generates a 5V square wave. I therefore needed a tiny 12V to 5V drop […]
