The IN-13 is only 4mA to fully light up. I think the formula for R3 and R4 is P=(I^2)(V) since they're in series and that gives less than 0.1W for both. So I could use a 0.25W resistor for them. Does that sound right or am I using the wrong formula? On Monday, May 6, 2024 at 10:44:31 PM UTC-4 gregebert wrote:
> These tubes draw quite a lot of power. I've only worked on the IN-9, and I > recall it needed close to 20mA to get a full glow, so 1-2 watts is the > right ballpark. R1 & R2 will be around 100mW worst-case, so 0805 should > work. > > SMT resistors put a lot more of their heat onto the PCB than a traditional > thru-hole resistor because of direct contact , so be sure to measure the > temperature carefully. Most PCBs (FR-4) have a glass-transition temp around > 130 degrees C, so you want to be well below that for reliability. > > On Monday, May 6, 2024 at 4:09:31 PM UTC-7 Zachary wrote: > >> [image: IN13.PNG] >> >> Hi, does anyone know what are the minimum required specifications of the >> resistors R3 and R4 for this IN-13 driver circuit? The voltage rating >> obviously needs to be >150V but what about the power rating? 2W and 1W seem >> very high. I'm trying to make small PCB sockets with only SMD components >> but potentiometers above 0.5W are very big. >> > -- 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/d6e11d7d-780a-46aa-ab4f-c223fff2b5a3n%40googlegroups.com.
