Many DICMs had an INH (?) lead that provided a ground when the ICM was engaged. Tha could be used to hold up a relay. If you have your buzzers leaning on battery and use the DICM to send ground you can use that ground to close a relay. It's been a while since I've done it, but it's not hard. We used to use WECO/NT 17B KTUs. They were -24VDC DPDT relays.

Sam


"Where are we going and why are we in this hand basket?"