[ARC5] ARC5 CW Question

[w4thq at cox.net]

The Apollo program during the 1960's and 1970's had complex relay logic in the control systems of both the launch vehicle and ground support equipment.  Because of RFI-EMI problems, NASA required double-anode zeners across all 28 volt crystal-can relays.  We found this approach was effective.  We also discovered that the back-emf would "ring" and was not just one spike.  The drop out time was not significant in our application so I don't remember what it was exactly.
John  W4THQ