See, I guess that's the issue. The DCC system cna be considerd a 'black box' device and one never needs to know jus thow the 'magic' happens. Treat it as "power goes in these two wires, and power comes out these two wires at a varying level to drive the motor" and that's really all you need to know. As it happens, in my re-reading of old MR's I just came to the first of the Ravenscroft MZL articles, and while an individual zone conenction is easy enough to follow, a whole layout's worth would be back to the maze of wires. With all those rheostats and relays I can't imagine it's actually a lower cost solution, not these days. It certainly may have been the best way to go before the advent of DCC. Each new 'extension' to basic cab control kept improving the flexibility of running multiple locos with multiple operators, but even the best system is less flexible than DCC. Early command control left a bit to be desired - the first version of ASTRAC could run 5 trains if you bought both dual-cab sets plus the multiple selector unit. You still needed kill switches for sidings, and it wasn't flexible in that the channel 1 throttle could only control channel 1 locos. I suppose you could have installed 5 of the single channel units, but you were still limited to only 1 of each channel running at the same time. There were already cab control systems more flexible than that. It wasn't until DCC that we have true freedom, all systems between ASTRAC and DCC improved the situation but when you got down to it most couldn't do much more than an advanced cab control system.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Howdy, Paul,
If one uses the (admittedly outdated) NMRA detector circuit, which is relay-based, one can wire the biggest layout on the planet with the analog DC MZL system and never encounter a microchip.
I am a pretty good electrician. I just don't care for devices where I can't follow the electrical path and see (clearly, in my physical as well as mind's eye) how current flows from here to there.
Admittedly, I'm not a purist. My MDC power packs have momentum switches and brake buttons, so I assume that there's something like a Westcott TAT circuit somewhere between the 120VAC line cord and the regulated DC output. Since they work, I've never been tempted to open the casing and investigate. OTOH, I have been inside my ancient Tenshodo pack - had to convert the 40 ohm rotary resistor to a potentiometer to handle can motors as well as open-frame type.
Chuck (modeling Central Japan in September, 1964)
Chuck,I was with you until your last line. "For those who don't have it, don't need it and don't want to earn a degree in electronics to work on a complex railroad - I'm with you." Um, sorry, but your CTC-controlled power routing layout must need some serious electrical skills. If it took Ed Ravenscroft 4 articles to describe the basics, then it must be pretty difficult to install. I know I'm assuming "facts not in evidence" here, but from my limited understanding of it, it sounds like you need to know what you're doing when building it. I searched online, and turned up a quote of yours that said, "BTW, if anyone wants a challenge, work out the track wiring for a fully-signaled analog DC MZL control system." That doesn't sound like something one should tackle without some real electronics knowledge. Perhaps not a degree, but still...
DCC, OTOH, can be as simple as can be. Plug in the "brain", hook up two wires to the track, and one can instantly control up to 120 locos on any track in any direction. No advanced degrees needed, no complicated wiring, no block cuts, etc.
DCC can be as simple or as complicated as one wants it. It isn't for everyone, and it has it's flaws, but the one thing you don't need is vast electronics knowledge.
Paul A. Cutler III*******************Weather Or No Go New Haven*******************
Nope, nobody ever said it was, Randy.
OTOH, a lot of that wire was simply passing signal indications back and forth. I figure that, if I ever go to full ABS on the JNR portion of my MZL system double garage filler, getting lineside signal indications to the Master and Zone panels will easily double the number of identified wires, and probably triple the total wire footage.
There are several up sides to MZL.
For those as has DCC and likes it, fine. For those who don't have it, don't need it and don't want to earn a degree in electronics to work on a complex railroad - I'm with you. If this be heresy, so be it.
Chuck (Modeing Central Japan in September, 1964 - with 1960s control technology)
Reading old MR's, just finished an article by Bruce Chubb where he mentions some of the wiring on his old Sunset Valley. This is pre-C/MRI, pre Optimized Detector. Signal detection in those day swas the Twin-T circuit plus a booster, and he had 5 cabs. To hook all this up, he mentions a continuous cable around the railroad room connecting the four overhead towers. Approximately 100 feet of cable. With between 300 and 500 wires making up the cable! That's somewhere around 6-9 MILES of wire. And with all that, the most you could run was 5 trains at a time. Granted, all nicely signaled, with repeaters in the towers and cab signals, but still. Yup, DC wiring a large layout sure was lots easier than DCC...