HV507 Nixie Driver

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Jeremy Jones

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Sep 6, 2026, 4:23:26 PM (4 days ago) Sep 6

to neonixie-l

I am using the Microchip HV507 to drive (sink actually) IN-12b Nixie Tubes. The board has a ESP32-S3-WROOM-1 that is outputting four lines to a 74HCT245, since the ESP32 outputs 3.3VDC and the HV507 expects 5VDC, the 74HCT245 boosts the lines from 3.3 to 5.

And yes, the hour and minute labels are backward, for IN-12, they are correct for IN-14.

SCH_Nixie Clock IN-12b_V1_1-Nixie Clock_1_2026-09-06.png

20260906_150157.jpg

Martin Černý

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Sep 9, 2026, 8:59:32 AM (2 days ago) Sep 9

to neonixie-l

Watch out, HV507 maximum sink/source current is 1mA. You may be getting away with little bit more because you're using very few outputs for the nixies but you're running the chip right at its limit if the schematic is correct.