If you are driving nixie tubes, there actually isn't 300V between pins at the driver IC. If your supply is 200V, and the typical voltage drop of an IN-18 is about 140V when illuminated, the actual voltage-difference between pins is about 60V. That calculates to 0.6mm of spacing, which is still a violation for a 0.5mm pad-pitch (remember, pad-separation is less than pad-pitch due to finite pad-width).
My guess is that someone seeking regulatory approval/listing would apply conformal coating, or similar. Even if you can't meet spacing rules around nixie cathode connections, you should use extra effort to meet or exceed spacing rules between high- and low-voltage sections, and also between HV connections that can have high current, such as filter-caps and mains-connections. -- 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 [email protected]. To post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/d986982c-841b-424f-9253-959bb775f727%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
