Hi everyone:
What methods can be used to get individual structure lights to turn on and off randomly?
I’m thinking of something like an apartment building or an office building where I want lights in various rooms to turn off and on on their own in a random pattern. Ideally I’d like to do it so that each building has only two leads for power if that is possible, hopefully without spending a fortune on circuitry.
Any suggestions?
Thanks
Dave
Dave,
This is one of the uses that the NMRA’s new LCC (Layout Command Control) standard addresses. Might be some ideas there: http://www.nmra.org/news/facts-about-lcc-new-layout-command-control-standard-nmra
Products based on LCC are just starting to hit the market, so might be worthd oing some research into who is offering what and perhaps giving things a year or so to shake out if it sounds interesting.
Woodland Scenics new system has manually swicthed controls,but not sure about automation with it, although would seem to me to be a useful option for them to offer.
On the face of it, LEDs will be easier to tie into an automation circuit than bulbs will be, besides their other advantages.
I’m always keeping an eye out for neat electrical gizmos at flea markets, surplus shops and “junk” stores.
I found this gem at an electronics surplus joint:
Each microswitch rides on a pair of adjustable cams so you can vary the on-off cycles. You could wire two sets of lights to each switch since they are N-C / N-O SPDT contacts so when the cam depresses the roller they will switch from one to the other.
You may not be lucky enough to find this exact switch but if you get an old synchronous motor you can make your own cam or a drum and mount several microswitches around it for animating lights. The one I show above turns at 1 RPM but you can find slower ones or make your own gear reducer.
Alternately, I have found “stepper switches” that will advance with one pulse of input voltage and you could wire your lights to the outputs, some have as many as 48 positions, and use a timer circuit to step the switch randomly.
I’m sure there are solid-state, electronic solutions out there but this works for me and I can “see” exactly how it functions.
Just a few ideas… Ed
OK Mike and Ed!
You have presented me with two options which seem to be on the opposite ends of the electronic spectrum. Don’t worry, I’m not complaining.
The LCC concept is certainly interesting and obviously has huge possibilities, but there are two things that give me pause. One is the time factor related to how long it will be before products are available. The other is cost. The NMRA bulletin suggests that hopefully costs will be comparable to current devices. The prices for current accessory control devices already give me reasons to question the cost/benefit relationship. That means I really don’t want to wait until new products are announced which will quite likely cost more than I want to spend (do you hear the birds singing “cheap, cheap, cheap…”).
That brings me back to Ed’s suggestion but I also don’t really want a whole bunch of clicking and snapping going on under my layout either. However, beggars can’t be choosers so maybe the mechanical devices will rule. They can always be replaced at a later date. The wiring will already be in place.
Ed:
What voltage is needed to drive the low speed motors?
Thanks
Dave
You can always make your own, basically a turntable and lay some brass contacts strips on it, for controlling LEDs this will be perfectly fine because of the low current involved, and it will be all sliding contacts, no snapping contacts. There have been DIY ones in the magazines over the years, i remember one that used a coffee can turned my an old loco motor and the contacts were arranged along the can. A couple of layers of paper under the moving contacts on the can insulated them fromt he can - again perfectly ok for low voltage low current power. Then there’s all-electronic solutions using something like an Arduino driving solid state relays or power transistors to switchthe circuits on and off.
Lots of ways to skin this cat (sorry Lion)
–Randy
You might try using a PIC® Microcontroller (Programmable Interface Controller). The price is right but the learning curve can be really tough. If someone on the Forum has the knowledge to program one for what you need they work slick. All the goodies, chips and circuit boards are available on eBay. Once programmed they work flawlessly and a four output board and chip sells for under $10.
This is a programmer for the PIC.
http://www.ebay.com/itm/PIC-USB-Automatic-Programming-Develop-Microcontroller-Programmer-K150-N
Hi, Dave
The synchronous motors are always 115 VAC since they rely on the 60 cycle house current. The same motor that has been driving plug-in clocks for years.
I found a 6" x 8" pvc box that I mounted it in and it runs very quietly.
There are many sources for slow RPM motors that are more like 6 to 12 volts DC, like the noisy Walthers 933-1050 bridge/oil pump motor.
If you are not already familiar with ALL Electronics you should browse there for fun electronic goodies:
http://www.allelectronics.com/
They usually have lots of handy stuff for model railroad use.
In fact, I just got an email from them showing little mercury switches for $2.25 ea.
http://www.allelectronics.com/make-a-store/item/ms-40/mercury-tilt-switch/1.html
You could glue, or make holes to sink the switches in, at varying angles onto a wood square with pivots, then a crank arm to a very slow motor that would essentially “rock” the switches back & forth to make & break for your lights. It would not have to make a complete rotation so the wire would just flex with the rocking of the “switch bar”.
http://www.allelectronics.com/make-a-store/item/dcm-351/24-vdc-gear-motor-w/turntable/1.html
If you don’t want little glass vials of mercury under your layout you can use nearly any one of these snap-action “Microswitches” and drive them off your own rotating drum with varying lengths of strips glued on to activate the switches at random lengths and times.
http://www.allelectronics.com/make-a-store/category/727/switches-snap-action/1.html
Your request was for random operating lights and mechanical switches are not normally random. I’m not knocking the cam operated switches they work very good. While I don’t have any PICs programmed for long periods they are random. I’m not into programming so I’m asking for help from some sharpies out there. The PIC modules are available in an eight output configuration for under $10.
Still waiting on some sharpies with PIC knowledge to chime in and give us your thoughts.
Mel
Modeling the early to mid 1950s SP in HO scale since 1951
My Model Railroad
Hopefully I’m not violating any rules here, but there’s a company that makes such a circuit…(Modderator, if it’s inappropriate please remove, sorry)
www.eastcoastcircuits.com/ They make a pretty good circuit for the price. It’s called a random lighting cirucit. Since I’m not an electronic guy, I would rather buy something like they have…
Neal
That looks pretty neat, Neal!
You are not violating any forum rules by pointing a fellow member to a product that will help solve an issue.
If you were selling these and trying to solicit customers here, that would clearly violate policy.
That board would satisfy Dave’s desire to have the unit within the structure and have only two wires coming out of the structure.
[Y] Ed
Mel,
I suspect PIC devices is one of the ways that LCC can be implemented. If so, that prices sounds good to me even if you hear the chicks going “cheep, cheep…” once someone gets a “command station” for LCC to market.
Dave,
If you want a simple, two-wire solution for multiple lights in a building, it almost has to be some sort of addessable controller.
On the other hand, old school stuff like gmpullman showed should be easy to find on the surplus market. I suspect cost kinda depends on what scrap value for the metals involved happens to be.
THat’s why I suggested Arduino, boards can be had for not much more the PIC board, and no programmer needed, they have USB on them. Arduino was designed for non-engineers to work with. There are NMRA DCC, Loconet, and CMRI libraries already for Arduino.
That’s the key to a ‘cheap’ interface device for any bus, like LCC - someone, or you, needs to develop a library to access the protocol - not exactly an easy job but if someone does so and makes it freely available you can build on that.
–Randy
I looked at this link and their “Random Lighting Circuit” looks like it would do the job. My only issue would be that the timing is pretty short, 5-45 seconds. At that rate, the structure might seem to be calling for attention.
I have no idea about the rate on it… Drop them an e-mail… be interesting to see what they say… Wish i was more tech savvy…
Here’s someone who did it with an Arduino Nano. Unfortunately he doesn’t provide the sketch. It shouldn’t be too difficult to find a sketch that will randomize the lights for you.
Steve S
You convinced me Randy, I have an Arduino Starter Kit on the way. I’m hoping an old dog (ex 50 year electronics techie) can learn a few new tricks before he croaks.
Mel
Modeling the early to mid 1950s SP in HO scale since 1951
My Model Railroad
http://melvineperry.blogspot.com/
Bakersfield, California
Dave,
I don’t have any answers to your question - but I can see how cool it would be to have a building have randon lights turning on and off.
Let us know if the Arduino kit works out.
In the old days we would have has a batch of switches to control the lighting - nowadays you can let a circuit board do it all for you. Is that progress?
Okay I’m a luddite that works in the computer industry - go figure.
Take some pictures as you go, and keep good notes of how you program the Arduino unit.
This would make a great how-to article for a certain model railroading magazine.
Wow - lots of possibilities!
For those who suggested the mechanical devices - thanks very much. I think I’m leaning towards the electronic options but I will keep the others in mind.
Neal:
The Random Lighting Control is a great product but I would need a bunch of them to do what I want because they will only drive 6 LEDs each. The low Canadian dollar is becoming a serious issue, and it is predicted to go even lower by the summer so buying 12 - 15 of the RLC units would get expensive.
Steve and Randy:
Arduino obviously addresses the issue about the number of LEDs that can be driven by a single unit, plus there is apparently greater flexibility in the timing settings.
Mel:
Where did you order your Arduino kit from?
Thanks everyone!
Dave
Just ordered the book ‘Arduinos for Dummys’. Sounds like its aimed right at my level!
Dave