Current limiting requirement for VFD's ?
- View SourceWhile working on the IV-4 vfd smartsocket I haven't used current limiting for any of the segments and this morning I noticed that the phosphors on the segments are a mid grey colour. A new tube has crystal white segments.
When I first use a new tube I notice a period of a few seconds where the brightness is very intense, before it drops back to a more normal level. I have read mixed ideas about whether or not current limiting is absolutely required, but am curious to know if I am not applying to much current to every new tube and rapidly aging them in the process or does anyone know if all new phosphors go through a burn in cycle ?
I'm just about to set up a tube with current limiting resistors on each segment to see if there is any difference.