I've got a 45-degree crossing on my layout. Never fails that when I take my eyes away for one monment, two trains arrive there at once, and --- well, you know.
I'd like to install some kind of detector so that if a train is in the crossing, the perpendicular track power is killed. I assume I use some kind of block detector?? Recommendations please. (By the way I run DCC, a Digitrax Zephyr)
Jim, Modeling the Kansas City Southern Lines in HO scale.
The only problem with that is you either need to have an operator stationed there all the time, (which would be pretty cool during op. sessions but bad for 1 person ops) or only run one train. (although running one train would solve your problem anyway...)
DC would probably be easier if you don't want the "on/off" control method, for smooth stop you'd have to hook your layout up to a computer.
I don't speak for any organizations on this board. All opinions are my own.
There are three ways you could go with this.
Manual - as Jamnest said in the first post.
Full blown computer control - Use a BLD-168 or smaller block detector connected to LocoNet and computer controlled.
Simple Automatic control - Use a simple photo detector (as available on eBay most times), and relays to shut off the track power as needed. No computer required, but you do need to know how to design (figure out) how to install and wire the parts together.
The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.
(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.
The simplest and cheapest solution is have engineers keep their eyes on the track. You might add train detectors with signals. That is prototypical.
jxtrrx wrote:I'd like to install some kind of detector so that if a train is in the crossing, the perpendicular track power is killed. I assume I use some kind of block detector?
Almost all the DCC vendors make track occupancy detectors based on current draw.
It doesnt matter if your DC or DCC, a detector on both will work, just be sure the DC detector doesnt filter the AC signal much.
Linn Westcott designed a Twin-T detector which uses 2 power transistors cross connected to make the detection. Bruce Chubb has a detector design also.
You would need a relay that kills power to the "other" track, if a train enters the "other" track it can't get power to detect and drop the "first" relay, so you get a lockout feature.
The most important thing is you should set up a rule that any train that has to get thru this crossing has to stop and get clearance before proceeding. Something your dispatcher has to qualify. Running by train order only solves everything and you don't need detectors.
lvanhen wrote:I thought all the "techies" were supposed to be at the DCC forum
This detector is they type that senses current on the rails so only a locomotive, lighted passenger car, or caboose will be detected. Resistor wheel sets are highly recommended to protect the center of the train.
One of these circuits would obviously be needed to protect the other track as well. When they are both installed, as presented, if the one track is automatically powered down, a train over running the block could not power down the other.
One could also make the power cut off block a different size from the "detection" block.
Another option would be to put a warning buzzer or bell into the circuit to get the engineers attention.
I know you'll say I'm a weenie... but I was thinking of something I could just buy and wire up. Anything like that? I see some "detectors" on websites, but don't know if that's the same as something that will provide a switch-type connection for power. (You start talking relays and transistors, and I get out of my comfort zone quickly).
Oh, and sorry if I posted in the wrong section.
jxtrrx wrote:I know you'll say I'm a weenie... but I was thinking of something I could just buy and wire up. Anything like that?
You start talking relays.. and I get out of my comfort zone quickly
cwclark wrote: DALLEE electronics sells a very nice train detector that uses an AMP draw indication to set off a N/O - N/C relay. If a train is present in one block than it is wired to kill the power to the rails of the other block and with two detectors the opposite can be achieved. there are enough connections on the DALLEE relay that it can also signal the trains if you want to go that far. Heres a picture of their train detection circuit. See how easy it is?.
Model Railroader magazine