On Friday, January 10, 2020 at 2:26:26 PM UTC-6, orange_glow_fan wrote: > > >
*Hi orange_glow_fan;Interesting winding mechanism!Some thoughts:1. Those contacts are quite "Beefy". They are meant to conduct relatively high currents.Often, they require a small spark, on opening, to keep the contact surface clean.Adding a small capacitor across the contact provides this cleaning spark. (In this case the spark happens on closing instead of opening.)I would suggest a 0.1uF cap.2. This 0.1uF cap would also delay the MOSFET turning off as suggested by *gregebert. *The RC time constant, for a 10K pullup resister, would be about 1mS. Seems a bit short:Maybe by making the pullup 100K to get an RC of 10mS would be better.3. The IRF9340 is OK *with an on resistance of 200mOHM is a bit weak but should work fine since it's ON for only a short time. 4. It looks like the contacts need some adjustment. They look somewhat out of alignment. 5. Is that a little metal "Prussian Helmet Spike" I see in the lower contact? This might have been the "Root Cause" of the failure. For a clock that has run for 50 years the designers must have done something right. Maybe just giving the contacts a little contact filing would do the trick. redrok > [image: relay.gif] > > > -- 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/df66c0ad-c930-4190-9439-a136bf332c7b%40googlegroups.com.
