Thanks for your comments. Checking the specs for the HV5522, the recommended operating voltage is 10.8-13.2. I'm working from part specs and schematics for several clocks that I own. The MOD-6 runs the HV5522 at 8v, the NixiChron runs at 5v to the HV5530, and the Spectrum 18, at 5v to the HV5522. I understand the purpose of a level shifter, but I don't know how to implement one. In any case, it appears that others run the chips reliably at lower voltages, so we'll see.
Regarding the power supply, that is the Tayloredge.com 1364. It is the same power supply used in the Mod-6. I've read about the difficulty in creating a stable design and that's way over my head, so I think the 1364 is the best way to go. I just ran out of pins, so time to buy Diptrace lite! On Tuesday, April 21, 2015 at 12:02:20 PM UTC-4, gregebert wrote: > > > Thanks for mentioning the HV5522. I wasn't aware this device existed. Just > be aware that VCC is nominally 12V, so you cant drive the inputs with > TTL-level signals (you need a level-shifter). That shouldn't be a problem > because you only need 4 or 5 signals from the Arduino. Going direct-drive > is a wise choice, and you wont regret it. > > I doubt the 10uA leakage current will be enough to cause unwanted glowing, > but if you want to be extra paranoid then use the HV5530 with a higher > voltage rating. Leakage tends to be proportional to the voltage-stress, so > using a higher-rated device should result in less leakage. I suspect the > manufacturer tests their devices > 300V, and the least-leaky ones are rated > for 300V, whereas the leakier ones are rated 220V. > > I can't tell what's inside the HV supply, so that's my only concern. > There's a history of problems with HV supplies on this group. I prefer a > voltage-doubler from the AC mains, which gets me +340VDC in the US. It > wastes a bit of energy in the dropping resistors, but I dont use a > transformer so that reduces the loss. You just have to be very careful with > the design because it's NOT isolated. > > > -- 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/5f23d59e-be4f-4f88-befe-cda54987981a%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
