OUR (yes, my wife is very involved) garden railroad is undergoing a major upgrade this year and that includes adding 8 new buildings with LED lighting. I recently purchased a "Moonrays" #95431 Low Voltage Outdoor Transformer, 120 watts, 12 volts to power the lights. This transformer has several cycle possibilities, including some that turn the lights on at dusk and turn them off 4, 6 or 8 hours later.

I think it would be a little boring to have them all go off simultaneously at say, 4 hours after dusk. What I would like to do is to put a (reasonably priced) device in at least some buildings that will turn them off before the transformer cycle ends, say at 2 or 3 hours after dusk.

On advice from a garden railroad forum, I have searched the internet and found many timers, but none specifically suited for my purposes. Also, I need to mention that I understand electricity reasonably well but know very little about electronics and the related terminology.

Anyone have any comments or suggestions?

Thanks,
David

 

IMO a micro-controller would make this project fairly simple, but that would require a decent bit of learning before you'd be ready to design it.

Sorry I can't help with anything else.

 

Sounds like a perfect job for a Picaxe! Inexpensive, easy (BASIC language) learning curve, plenty of support!

This isn't an advertisement, I play with 'em all I can! I also code with PICS, but for speedy development and for many finished projects, it's hard to beat 'em! The programmer is free and the chips are inexpensive.

Forum: http://www.picaxeforum.co.uk/
Home of the Picaxe: http://www.rev-ed.co.uk/picaxe/
U.S. Supplier: http://www.phanderson.com/picaxe/

Give it a look!

joe

 

Here is a simple(ish) circuit that might help you out. If you can work it out you will see that you can select any time you like with the right selection on outputs. I will leave the description at that just to see what sort of reaction I get from the other guys. You stated you weren't very up with electronics so I am guessing this might be a bit above you but I think it is no more difficult than the micro solutions. This one may help you learn on the way.

 

Sounds like a perfect job for a Picaxe! Inexpensive, easy (BASIC language) learning curve, plenty of support!

This isn't an advertisement, I play with 'em all I can! I also code with PICS, but for speedy development and for many finished projects, it's hard to beat 'em! The programmer is free and the chips are inexpensive.

Forum: http://www.picaxeforum.co.uk/
Home of the Picaxe: http://www.rev-ed.co.uk/picaxe/
U.S. Supplier: http://www.phanderson.com/picaxe/

Give it a look!

joe

Thanks, Joe. A model railroad electronics guy recommended the PICAXE and I did some study but didn't find what I was looking for and wasn't able to absorb enough to invent it myself. Apparently I grossly underestimated the complexity of the problem.

My mechanical engineer's mind assumed that, by now, the electronics world would have already created a $2.00 device that would see a 12v circuit come on and, after 2 or 3 hours, turn it off and keep it off until the 12v feed shut down. No such luck.

I think I will go on and investigate WK's proposed circuit and see if that is feasible (and affordable). If not, I may take my PICAXE study to the next level.

Thanks again,
David

 

Here is a simple(ish) circuit that might help you out. If you can work it out you will see that you can select any time you like with the right selection on outputs. I will leave the description at that just to see what sort of reaction I get from the other guys. You stated you weren't very up with electronics so I am guessing this might be a bit above you but I think it is no more difficult than the micro solutions. This one may help you learn on the way.

G'day, wk.

I was able to decipher most of the components (what is a VCC?) and the general concept of the circuit, but, since I want to put the device in 5 or more buildings, cost is a consideration. The only price I found for the NE555JG was $12 each. The MC14017BCL price is apparently an international Top Secret. Since it looks like I would need at least 20 of them, can you give me an estimate of what they might cost?

Thanks for your help,
David

 

Well lets start from the begining. VCC really just means the colector voltage of a transisitor. In this circuit you can replace the term VCC with +12V. I am not sure what sort of gold plated NE555 they are supplying but if you pay more than $1 you are being ripped off. With regards to the MC14017BCL this was just used as an example. Try looking for a CD4017 as it is the same thingand should only cost tens of cents each. You should be able to build the complete circuit for under $2 so that would be $2 per building. As for the NE555 you could try looking for an LM555. If you look at Digikey or Mouser they should have a variety of parts.

Hope that helps. Yell if you would like a bit more info.

 

The only price I found for the NE555JG was $12 each.

The NE555JG is spec'd out from -40 degrees C to 125 degrees C. If you don't need that type of specification, you can go with a cheaper NE555D, 0 degrees C to 70 degrees C from Mouser ... at $0.45

 

Normally VCC refers to the positive supply V to an IC, may also find +VCC & -VCC. A 555 should run around US $ .50 or less.4017 - .50 to 1.00.
Speaking before I think, might use a 4060 counter which has its own clock and a NAND gate [cheap]; at desired time selected output goes high, is inverted & connected to gate input along with Woops, gate not needed, use output to inhibit clock so time stands still.[TBD], selected output also connects to pin 2 & 6 of a 555. 555 acts as LED driver up to 200mA. Whin input goes high , 555 resets turning off lights. Next day every thing is reset at power-up.---I think Two cheap ICs 3 resistors & one small cap + the LED- one unit for each bldg. no extra wires except for power.

 

I want a wife who wants to get involved in projects like this

At least mine lets me get on with projects I want to do without nagging.

I'd be interested in what you do for the final result. Once we get our house extension done, one of the rooms will become a hobby room where stuff like railways can get set up and left and I'll be looking to do things like lighting and sound circuits for it.

Nick.

 

Hi

An additional thought would be to use some sort of detector circuits, to trigger lights coming on and off as trains approach and leave the building.

Possibly some sort of light sensor under the track so that the absence of light when a train goes over it is a trigger and then another the other side of the building.

Nick.

 

Hey guys. Try doing a search for DCC control of railways. You will be amazed at some of the things they can do.

 

I would consider a large picaxe, maybe a 40 series with many I/O channels.
Once when power is applied the various outputs could be cycled based on a program sequence you decided, even some variables and random cycles could be included. Maybe even several selectable programs could be used. The durations could be anywhere from seconds to hours. If the load is a simple LED then it can likely be driven from the outputs, or if it is larger a driver transistor would be required.
As for options, the sky is the limit!

If you need specific help feel free to contact me
Len

 

Another discrete component choice: A common clock for all buildings could be used, or a clock for each. Clock set for 10 to 30 minutes. A 4017 divides clock into 20 min incriments, or as shown #7 would be 2hr, 20 m.; #9=3hr. When selected out. is reached, it is applied to clock enable, shutting out the clock- time stands still untill power is shut off. At power-up, C3 momentairly holds reset high. So at minimum per house - 1 each 4017 [ or 4022, div by 8, different pin-out ] PNP transistor, cap, 3 Rs & LED. R5 depends on number & V drop of LEDs, about 360Ω as shown @ 20mA.

 

Thanks very much for all the excellent thoughts. One of our railroad club members had this thought, so I ordered one to try. Not exactly a $2 device, but since I don't have an electronics stash, I would have to buy all 35 bits separately. This kit gets it all to me at once.

Because it has a max 2 hr 17 min limit as delivered, I will have to buy some components to increase the time.

I will provide an update when I get it running.

Thanks again,
David

 

Sounds like a good start. to stretch the time , just increase R1 from 390k to 750k to 1M. Later, can use timer as a master clock @ around 15 to 30 min. to feed all houses with a one IC time delay, with parts count costing around $ 1.50 per house max.

 

@ All Electronics per house = $ 1.67; The Electronic Goldmine = $ 1.43, sub 4022 divide by 8; 4017 out of stock, resistors counted as .10 ea as only available in 100 lot. Circuit breadboarded with 4022 with results as stated. With so few parts, a small piece of cardboard will do for ckt board.

 

Hi Bernard,

I think I am keeping up with all the info ok. After I get the kit in my hands (shipped today), I can noodle it out better. Some of the houses get their 12v from the transformer individually and some (as many as 4) get a single feed for the group. Since the wiring is already underground and the Chief Gardener (see US in the first post) has planted over it, I will have to do some serious pondering about the best way to implement a master clock and still have a variety of turn off times.

Thanks to all who have commented,
David

 

For about $1.00, can add a clock for each house.& by then you will know all about 555's.