I too would be interested in a kit if you are considering making such a thing available.
- Richard On Monday 26 February 2024 at 18:50:05 UTC paulvr wrote: > The flyback converter is built around the TI LM5156H. This IC was selected > because it has an external mosfet, which means the voltage on the primary > side can be increased considerably and the winding ratio does not have to > be very high. An external mosfet generally also has better properties that > improve efficiency. The chosen mosfet is very small and difficult to > solder, as an alternative I can recommend the IPP17N25S3-100. > The flyback transformer is from Würth from the WE-FLEX series. The > insulation voltage is not great considering the output voltage, but I have > not been able to detect any problems. The achieved efficiency is between 70 > and 80% depending on the input voltage and output power. The output power > easily reaches 6 to 7 Watts depending on the input voltage. Minimum input > voltage approximately 9 Volts, maximum 16 Volts limited by the LM5156H. > The filament power supply is built around TI's SN6507. That is a fairly > new IC and one of the few forward converters I have found that can supply > up to an ampere and more. Together with a Würth push-pull transformer it is > a good combination to supply the 6.3 Volt up to 600 mA. The SN6507 has > programmable current limiting, but that doesn't really work well with the > filament which has a very low start-up resistance. The converter remains in > current limiting mode when the programmed current is too low. Efficiency in > combination with the buck converter approximately 80%. > > Op maandag 26 februari 2024 om 17:30:59 UTC+1 schreef David Forbes: > >> Paul, >> >> This is quite a nice project. It looks like a very clean display. >> I have run out of the custom transformers I had made in 2006, and I'm >> quite interested in using off-the-shelf ones in the future. Would you be >> willing to share a schematic of what you made? >> I also appreciate using SVG rather than rolling your own graphics. That's >> a nice standard solution that makes sense in this age. >> >> >> On 2/26/2024 2:12 AM, paulvr wrote: >> >> This is my first post in this forum and I would like to introduce you to >> my version of the scope clock. Mainly inspired by the work of David Forbes >> and Grahame Marsh. >> The work is not finished yet, but I have reached a milestone for myself >> in that all components are on one PCB and only one voltage source is >> required, nm. 12 volts DC. >> The high voltage is made using a standard Würth WE-flex transformer, plus >> and minus 250 Volt. The filament voltage is provided by a buck and forward >> converter and a standard Würth push-pull transformer (6.3 Volt to 600mA). >> The MCU is an STM32G491, mainly chosen because of the integrated 12-bit >> DACs. The image composition is completely DMA controlled and works >> independently of the CPU, which therefore has a lot of time for other tasks. >> The characters and graphic shapes are encoded as SVG path. >> An ESP32 has been added to achieve the correct time according to the NTP. >> Operation is entirely via a web server running on the ESP32. The software >> is not finished, and not all functions work (work in progress). >> The next step is to try out other CRT tubes and make a housing. >> >> Regards, >> Paul >> >> -- >> You received this message because you are subscribed to the Google Groups >> "neonixie-l" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to neonixie-l+...@googlegroups.com. >> To view this discussion on the web, visit >> https://groups.google.com/d/msgid/neonixie-l/4e60fa43-a9b5-40b5-8381-5a968b45d480n%40googlegroups.com >> >> <https://groups.google.com/d/msgid/neonixie-l/4e60fa43-a9b5-40b5-8381-5a968b45d480n%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> >> -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/2afb5693-f132-492e-b0b9-47fec8cadb03n%40googlegroups.com.
