8.9k would be correct for 180V. You don't need to figure in anything else for direct drive. If the software/hardware uses PWM to control brightness, it will still be expecting 8.9k resistors. If the display is actually multiplexed, that would be different.
On Thursday, May 5, 2022 at 10:43:16 AM UTC-4 Don Moore wrote: > I apologize for the title of this post. I changed the body without > updating the subject. I don't see a way to edit it. > > On Thursday, May 5, 2022 at 10:41:23 AM UTC-4 Don Moore wrote: > >> Hi - new to this group. Brand new to nixies, and I have introductory >> experience with Panaplex displays. I have a direct drive design that uses >> current sinks in each cathode connection. >> >> It appears that with the nixie, the anode resistor supplies the current >> limiting function. I am using Neonixie's 6-digit clock chip and design >> from 2006, linked to in a recent post here, that drives 74141s to drive the >> tubes using direct drive. I believe the chip uses PWM to drive the tubes, >> but I don't know what the duty cycle or frequency is. I am curious about >> determining the anode resistor value. >> >> My tubes are Z5660M, which have a minimum recommended power supply of >> 170V. Let's assume 180V. The sustaining voltage is 140V. The datasheet >> lists Imin = 3 ma, Imax =6 ma and Ipulse = 20ma. Would a baseline to >> determine the anode resistor be to assume something in the middle like 4.5 >> ma, which would be about 8.9k at a 40V drop? It seems like tweaking may be >> needed, and to simulate the actual PWM signal to see what intensity >> results, and see if the value needs to be increased or decreased. Am I on >> the right track? Thank you in advance. >> >> Don >> > -- 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 view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/49d9c654-410e-40b5-80c5-a24d043399aan%40googlegroups.com.
