Layout Lights

[Heinz57]

Hi all,

I am in the middle of re-wiring my layout lighting (I had a few problems with the previous serial 'bus')

So I have had a thought about having the lights essentialy 'automatic'. Would it be perhaps possible to include some sort of simple timer circuit to let the lights go on and off automaticaly, perhaps every 20 or 30 mins?

I currently run about 25 lights (Mostly LEDs) on a 16v AC feed.

The desired effect I want is just a simple day and night look.

So how could I do this, does anyone know of a known working circuit for the job?

Cheers,

Heinz

 

[freelander]

Hi have you tried the timer you would use in your house for a table lamp to come on at a set time and then go off at your chosen time, they can be set at 5,10,15,20+ min all you would have to do is wire your lights through a socket for 16v.

freelander

 

[Heinz57]

That might work, but wouldn't that mean the timer would need to be reset every time the layout is unplugged?

 

[krus_aragon]

If you're in an amateur electronics mood...

A 555 timer is the usual choice for periodic on-off switching (in it's astable circuit layout), but it isn't really designed for such a long period. (I think you'd do well to get past a minute on/off.)

If you're happy to have the on and off periods the same length, you could have a 555 timer on a reasonably long astable period, and run the output through a bunch of flip flops. Each flip flop will halve the frequency, i.e. Double the length of the on/off portions. So if you have a 555 set up with the appropriate resistors for a ~1 minute period, and run it through six flip flops, you'd have a waveform with a ~1 hour period: 30 mins on, 30 mins off.

The power from the flip-flop would most likely not be enough to power all your lights, so you'd want to use a single transistor to give sufficient current for all your lights.

You mentioned an AC power supply, which is at odds with a digital circuit like the one I've described above. Your LEDs would only be powered half the time on an AC supply anyway. (Is there a bit of flicker from them, perhaps?) To use a 555 timer, you'd need a either a homemade or off the (electronic component) shelf power regulator for it.



Okay, having writtrn all that, I admit it may well be over many people's heads. I'll have a think about some other approaches using more common household items.

 

[Heinz57]

Yeah I'm deffinatly in the mood for some electronics!

I like that idea, and I cant see why it wouldn't work. Do you know of a schematic for the circuit?

I suppose what I could possibly do to solve the AC problems is perhaps put a bridge rectifier and a couple of other bits and peices before the timer circuit to convert to DC?

Cheers,

Heinz

 

[Don2912]

Here's one that uses a photocell: http://www.sentex.ca/~mec1995/circ/sensor4.htm

Long Delay Timer: http://www.redcircuits.com//Page126.htm

There are many more useful circuits here: http://www.redcircuits.com

And some more here: http://www.discovercircuits.com

HTH,

Don

 

[Heinz57]

Thanks Don for the links.

They look pretty useful. I shall have a proper read through them later on.

Cheers