So I just started working on a little project for my school's theater. It's pretty basic, just need to make a small, cheap system that can be used to cue actors/technicians that their cue is coming up by turning a light on and off. (Little side note but I have little to no experience in circuiting so if I make a mistake, am misinformed, or just am going about something wrong) I was planning on using some backlit Led push buttons on the control panel and some basic LED's to be used to signal the operator that their cue is coming/on with some 2 core wire going to each station. I was tempted to use actual light bulbs (of a lower brightness so that they only attract the attention of the operators and not anyone else) but I'm not sure if that'd take too much power or make things too difficult. I was having a bit of an issue figuring out how I was going to do power since I was aiming at having 4-6 different stations and I didn't really want to have to have 4-6 different power supplies so I was hoping there was some way I could split those up so I could have minimal wiring and make it as clean and simple as possible. The stations will each be between 10-100 maybe 150 feet away depending on where they each are. Hopefully taking this project on wasn't biting off more than I can chew but I do have quite a lot of time and am willing to go through some trial and error.

Thanks in advance for any help!

 

Assuming its only 1 "control" station and multiple "only led stations" then you simply put a power supply in the control box.. (any simple wall wart type ac/dc power supply..5V, 12V)

You simply have 2 wires going to each box carrying the power to each led station.
Just use regular switches (by that I mean not momentary) and the proper resistor for each led and when you flip the switch..voila...

assuming a 20ma 2Vf led
for a 5V power supply use a (5-2)/.02= 150 ohm 1/4 Watt resistor
for a 12V power supply use a (12-2)/.02= 500 ohm 1/2 Watt resistor

 

Assuming its only 1 "control" station and multiple "only led stations" then you simply put a power supply in the control box.. (any simple wall wart type ac/dc power supply..5V, 12V)

You simply have 2 wires going to each box carrying the power to each led station.
Just use regular switches (by that I mean not momentary) and the proper resistor for each led and when you flip the switch..voila...

assuming a 20ma 2Vf led
for a 5V power supply use a (5-2)/.02= 150 ohm 1/4 Watt resistor
for a 12V power supply use a (12-2)/.02= 500 ohm 1/2 Watt resistor

I just want to double check the last part.

5V: I get 0.06W, you are suggesting 0.25W.
12V: I get 0.2W, you are suggesting 0.5W.
Are you just rounding the values up so that they can use commonly available parts?

 

A "typical" safety margin used for resistors is 2 to 3 times calculated wattage..

 

So I can just throw those all in sequence as long as I have power somewhere on it? Also how can I make sure that each button only turns on one specific light? Or does putting them all in sequence just sort of do that automatically? And I can get those resistors pretty easily right?

 

Also the led's and buttons I'm using are these

Button:
http://www.radioshack.com/product/index.jsp?productId=2909787#showFullReviews

Led:
http://www.radioshack.com/product/index.jsp?productId=2062568

(also I'm not sure if those are over priced or not and if so do you know of a cheaper place I should be able to get those?)

 

A "typical" safety margin used for resistors is 2 to 3 times calculated wattage..

Thank you.

 

So I can just throw those all in sequence as long as I have power somewhere on it? Also how can I make sure that each button only turns on one specific light? Or does putting them all in sequence just sort of do that automatically? And I can get those resistors pretty easily right?

How far will all these people be from you?
How many stations/LED is there?

150 Ohm is standard resistor.
500 Ohm is not, but 510 Ohm is also standard so just use that. The small increase in resistance is not significant in this case.
However, the numbers above were calculated using some usual, but not exact values. Look up in the catalogs some real LED and see what real values they have. Then tell us, and we can recalculate the values of the resistors.

 

There will be 6 ish stations to start with but we'll be expanding it later on as needed. And some of them will be as close as 20 feet and probably 150' is a good estimate (we can't run wire directly as it'd be hanging in the air and we don't want that and it seems...less than safe) since it'll have to go to the opposite side of the auditorium.

 

That LED already has a built in resistor and is meant to be used with a 12V power supply..

 

Yeah, I was hoping that I could just strip the end off one of these:

http://www.amazon.com/Wall-Adapter-Power-Supply-12VDC/dp/B006GEPUYA

and put some heat shrink quick disconnects on so that I can replace stuff if anything breaks. OH yeah, how should I go about determining what gauge wire I should be using?

 

I mean they're just LED's so I wouldn't assume they need that large of a gauge. But I don't know how small they can go.

 

Its low current.. Any wire will work just fine..
20 to 24 AWG is fine.