[jcrawfordor]

I've heard of hybrid digital/analog systems in the US, I think a few smaller companies introduced them as an upgrade path - IBM/Simplex/Standard pretty much dropped support for these clock systems totally but lots of institutions already had them installed, so a cottage industry popped up of companies that made compatible equipment to keep them working and upgrade them over time. As far as I know virtually everything in the US was 24vdc but I'm sure there's some odd exceptions out there.

I've always had a weird interest in these systems since they tend to pop in large old buildings and are one of the many odd building systems you have to figure out sometimes - along with vacuum controlled HVAC and old phone systems. A small side project of mine right now is trying to get a working dental office communicator light system.