Circuitry, Leds, Effects, Wiring, Etc...

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PillowFire said:
I would like to add that, whilst everything said above seems complex, it is extraordinarily easy. A light sensor is not some fancy black magic configuration, it is simply a sensor unit soldered in just like any other component. As I imagine it, you could have the thing work as a variable resistor, so that the resistance variates directly correlating with the ambient light.

This basically means that in place of a potentiometer, you put a photoresistor. Perhaps you might need another resistor to make sure your LED's can't get blown out by a bunch of bright light. Or, you could just get a photoresistor with a certain min-max threshold fit for the LED's you are using.

The wiring and the schematic is very simple, but the effect is very high tech.

Depending on the backround light, the LED's will adjust in brightness as if by magic. Wonderful effect to all onlookers.

Might as well go all out and include some temp sensors to control the fan speed depending on how toasty it gets in the suit. Or even step up to a "saline detection system" that turns on the fans as soon as you start to sweat.
Isn't this fun?!? :D
 
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Well thanks for all the responses guys. I was planning on a photo resistor to automate the lights, as well as a switch and potentiometer to control manually. I have a friend whom is a circuit designer for a big company, so I'm going to have him help me make it.

When it's all said and done, I'll upload a schematic and pictures of it for use by all!

That said, I would still appreciate any and all ideas and help from you guys. Thanks a bunch
 
Glad you found someone local to help out. Hopefully, he'll give you this same information.

Everything sounds pretty straight forward to me (besides the dark switch). You want all the LEDs in parallel, and each one with it's own resister to maximize brightness, then solder a common lead (one side of all LEDs will be connected together). 11V/0.02A=500ohm resister for each LED.
I'll second the vote for this site, it gives you a sense of how everything is connected. Choose schematic.
http://led.linear1.org/led.wiz

For the potentiometers you would connect them to either side of the LED's parallel rail, so you can adjust all the LEDs together.

The dark switch is a bit more complex, let me know if you need help reading this diagram. You want a phototransister, it has better response and can be adjusted to a trigger light level.



This circuit has two transistors and a potentiometer.
One transister is the phototransister.
The second transistor will need to be a 2N2222 or equivalent, the suggested 2N3904 can only power a single LED. The 2N2222 has a rating of Ic Max=800mA, enough to power 40 LEDs.
The potentiometer is used to choose the trigger light level.
You can replace the relay in the diagram with your LED connections.
 
thatdecade, what software did you use to make that schematic? I am looking for a good modeling software for free. At school, we used multi-sim.
 
PillowFire said:
thatdecade, what software did you use to make that schematic? I am looking for a good modeling software for free. At school, we used multi-sim.

I know you asked someone else, but you might want to check out CadSoft's EAGLE - the free version is pretty nice for small projects (4" boards, 2-layer PCBs)
 
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I stole that pic from the linked website, usually I do my schematics freehand.

Multisim is just ok. I've had good experiences with ExpressPCB, it can also be used to have boards manufactured.
 
I have no design experience whatsoever. I've been using Multisim, and like thatdecade said, its just OK. It takes some tinkering with to get things to go where you want. I can imagine that although its more organized, freehand diagrams are just so much easier, infinite freedom...
 
sharkhead7854 said:
sorry to go off topic here but that is a beautiful plane in your signature

Thanks!!! Winter season around here has strong winds so i havent been able to fly her. sometime soon tho!!
 
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hey thatdecade just one question about the dark switch, how would you wire the leds to the switch if you have a total of 6. Just looking for some extra help with this im a little slow when it comes to circuit boards but im wanting to learn.
 
lightdrkled.png


Use the previous linked LED calculator site for the resistor values.


I had an idea walking through walmart the other day. They now sell those outdoor solar lights for $4. They come with a solar cell, white LED, a NiMH rechargeable battery, and a dark sensor switch. That is a lot of hardware for $4.

One of these could easily be parted out. You can replace the battery with a 9V, or leave the solar panel intact.

Solar panels are bad ass. You would never need batteries. !! whoo
 
Sorry I'm late to the party, Timone. If you need any particular help understand a concept or something, let me know. Your design sounds promising.
 
Thanks for coming dude, the party is just getting started. But yeah, when I said help, thats what I meant, I want to be able to figure it out myself:
The three separate branches splitting off to the fan, body lights, and helmet lights systems, those will be in parallel. After going through the switch, how should I go about choosing the correct potentiometer for the system. I know that I will need resistors for each LED, which I think will all go in parrallel, unless you disagree. How should I go about deciding what resistance to choose. I'm using multisim to help design the circuit, but I think it might be confusing me more than its helping me. I put a resistor over each LED, figured by V=IR, where each LED requires .02A. My battery pack is an 11.1v, so therefore I should divide 11.1/.02 to find the resistance required by each LED? What are the basic equations that I should know for this?
 
timonemycat said:
Thanks for coming dude, the party is just getting started. But yeah, when I said help, thats what I meant, I want to be able to figure it out myself:
The three separate branches splitting off to the fan, body lights, and helmet lights systems, those will be in parallel. After going through the switch, how should I go about choosing the correct potentiometer for the system. I know that I will need resistors for each LED, which I think will all go in parrallel, unless you disagree. How should I go about deciding what resistance to choose. I'm using multisim to help design the circuit, but I think it might be confusing me more than its helping me. I put a resistor over each LED, figured by V=IR, where each LED requires .02A. My battery pack is an 11.1v, so therefore I should divide 11.1/.02 to find the resistance required by each LED? What are the basic equations that I should know for this?

Yes, you have Ohm's law correct, R=V/I, where R is resistance in Ohms. However, to actually find the resistor for your LEDs, you need a slightly diff. formula.

R = (VS-VL)/I

VS is Source
VL is LED Voltage

So; R = (11.1 - 2.2)/0.02


I used 2.2V as a common for red LEDs.

Now, for the pot. You're going to need to choose a pot that goes from 0 Ohms, to a certain value. To determine that value, you need to use the same formula as above, but with a slight modification.

R = (VS - 1.8)/IT

VS is Source
VL is LED Voltage
IT is Total Current
1.8V is generally a LED's off limit.


You just need to substitute the total current, which would be 0.02A times the number of LEDs in a parallel circuit. This will give you the Ohms resistance you need for the pot to go up to, and possibly a little over.

Now, you just need to know the required wattage of the pot. For this use;

P = V x IT

IT is Total Current
 
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Awesome thats exactly what I'm looking for. Also, I was wondering two things:

1. For the body lights, is it possible to have it controlled manually by the switch/pot, and also by a photoresistor? I would like to have it so I have a switch to turn the lights on, and a switch for auto/manual.

2. Is it hard to make the fans automatically adjust to tempurature? Or is it just some sort of temp resistor?

Thanks a lot goku for all your help.
 
timonemycat said:
Awesome thats exactly what I'm looking for. Also, I was wondering two things:

1. For the body lights, is it possible to have it controlled manually by the switch/pot, and also by a photoresistor? I would like to have it so I have a switch to turn the lights on, and a switch for auto/manual.

2. Is it hard to make the fans automatically adjust to tempurature? Or is it just some sort of temp resistor?

Thanks a lot goku for all your help.


1. Yes, it is possible. Simply design your circuit using a slide switch that has 3 positions, 1 off and 2 on to separate poles. Connect one side of the switch to your phototransistor circuit, and connect the other side to power, or gnd, whichever side of the LED your auto circuit works on. That way, one way the switch will set it to auto, the other way it will always be on.

2. Automatic fans are possible, but somewhat difficult to calibrate. You need a circuit using a MOSFET and a thermistor. There's alot of tuts on those around the web, mostly for computer case fans.

No problem, glad to help, good luck. :D
 
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