Re: PointBuzz posts Demon Drop retrospect feature
The big difference between then and now is that some of the relay logic...any low-current relays you see in that cabinet that may have been used for logic...could be replaced with the PLC (far right). It is not clear from the photos...many rides of that era were driven by relay logic, but used PLCs for monitoring purposes (one version of the Vekoma SLC, specifically the one Geauga Lake had, worked that way). That can be shifted to an all-PLC design. There still needs to be some kind of interface, though, between the low-current and the high-current side of things.
One other thing that can be done today, though, is to drive the motors off of TTL circuits using a high-current motor controller. My guess is that the big-ass 3-phase contactor on the floor of the second cabinet is probably for the elevator, and the smaller contactors in the first and second cabinets are for the various feed motors. Some of those contactors could be replaced with motor controllers, which are basically just solid-state contactors. The neat thing, though, is that the controller can vary the power line frequency and control how much power the motor uses. The benefit to that is that the overall power requirements for the ride can be reduced, as the motors can use just enough power to do the job instead of running at full-bore all the time. That's even true for a very simple controller such as a soft-start unit.
In answer to your question, janfrederick, my guess is that for a similar ride designed today vs. a quarter-century ago, the electrical parts count is probably lower and the system is more reliable, but the individual parts are more expensive. I/O boards cost more than relays, but they have no moving parts, have a faster response, and a longer MTBF. The payback comes in the form of greater reliability and potentially lower operating costs over the life of the ride.
--Dave Althoff, Jr.
/X\ _ *** Respect rides. They do not respect you. ***
/XXX\ /X\ /X\_ _ /X\__ _ _ _____
/XXXXX\ /XXX\ /XXXX\_ /X\ /XXXXX\ /X\ /X\ /XXXXX
_/XXXXXXX\__/XXXXX\/XXXXXXXX\_/XXX\_/XXXXXXX\__/XXX\_/XXX\_/\_/XXXXXX