Home Forums General Discussion Technical Questions 1986 Dover composite relay logic

Beware the IBM relay testers that don’t have separate LEDs for the N/O and N/C contacts. It’s really easy to get the pins crossed up on an IBM relay, especially if you go through a whole controller. If the pins crossed up so both N/C and N/O are always made the Sees tester that uses the same 2 color LED for the N/O and N/C will test good.