"Help!" for: Electronics

[Spartan 010]

Ok, so in current speech of my lightsaber project, I wanted to include a recharge port, but not exactly sure what I need for it, ordering parts from the custom saber shop. got a 2mm power jack, and a chargeable battery pack. what else do I need?

If you never want to take the batteries out again to change them, the easiest thing I could think of doing, is taking apart a Duracell (or another company's) battery charger, add an extension wire of some sort to the unit, and then plug it up to the lightsaber port. That's what would do. You'll probably get a better idea from thatdecade or someone else.
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I have a question myself. I'm sure there is a simple solution but I just cant figure it out. I'm modding a Star Trek Phaser toy/prop (I honestly dont know why... I need a life, ) Anyways, if you have ever seen Star Trek: Next Generation through :Voyager, you may have noticed that it has the ability to turn the power up and down. Right now, I just want to work on the LED aspect of it. There are a number of LEDs near the front that tells the user what level it is on. Like this:

Basically, I was wondering if anyone knew how to do this. I would assume some sort of aduino is needed but I was hoping there was a simpler solution. All I need is a chain of LEDs to turn on or off incrementally on whichever button I press. "This button turns on 1 extra LED with each press, this one turns 1 LED off each press" sort of deal.

Thanks to Andrew Lambright, I'm hooked on Solid State Lasers and such. I'm trying to figure out how to get a visible-without-particle-debris, laser beam to shoot out of it. I thought about using a 110mW laser diode I found on Ebay and using a focusing lens/ magnifying lens would do the trick. But that can wait! (Unless someone has an awesome idea)

Thanks!

 

[thatdecade]

Can't help you with the laser, but the power level meter sounds fun.

Arduinos are a good investment, but are more then you need to spend. Can do a power level meter with a Decade IC and a Rotary Encoder. Wire the rotary encoder as the clock input to the decade counter, which is wired to your LEDs.

Digikey parts: P10859-ND and 568-3080-5-ND
Add some LEDs and misc other parts, and the Total Part Cost is still less than $5

This page describes how to wire a 4017 decade counter IC.
http://www.technologystudent.com/elec1/count1.htm

If the light pattern isn't exactly what you want, there are lots of logic ICs that can be wired to do what you want.

Edit: For example a Shift register, I think is exactly ! what you need. Digikey part number: 568-1484-5-ND

 

[Spartan 010]

Thanks man! I really appreciate it!! This is going to help a TON!

 

[thatdecade]

I forgot to mention that using the rotary encoder and logic ic only gives you a single animation. Spinning the dial clockwise ramps power animation up, spinning the dial counterclockwise ramps the power animation up. There is no down animation. Once the ramp up animation gets to the top, resets back to off and begins ramping again.

Can you live with that?

I also forgot to link to a good led bar graph (blue) you can use as a display.
http://www.sparkfun.com/products/9937

 

[Spartan 010]

That's awesome! Thanks!! If I could get it working, I'd be more than glad to live with it, haha

Im not sure if you remember or not, but a while back I asked for help concerning an Iron Man hand light up thingy. You made a schematic for it. (thanks again btw!)

I had an idea which I based off your schematic. I apologize for the not-so-professional schematic drawing. I'm still learning the symbols. (I REALLY need to memorize them.)

The basic idea is that 1 area is constantly on using a regular on-off slide switch. The secondary area uses a momentary/tactile switch to apply power. The power goes through a capacitor (I dont know what value I should use, or even if it will work) and then through a chain of LEDs which, in theory, (I got this idea from the way that the TV-B-Gone runs power through the LEDs) should light up kind of slowly, 1 at a time. (This is so long as there is power going through it.) When it reaches the "peak level LED," all LEDs "should" be lit up the same amount. When you stop pressing the tactile switch, power stops flowing, but because of the capacitor, the LEDs slowly fade off. (Hopefully from end to beginning. (unlikely but it would be nice)

What do you think? Ah, btw, I am still fiddling around with your idea. I'm just trying to look at every option available. Know what I mean?

Thanks again!

EDIT:
Well... I played around with this idea and tried it on a circuit tester. I was only able to get 2 of 6 LEDs to turn on that are back to back. All positive to positive and negative to negative, I can turn on WAY more. But back to back, only 2. I used 4.5v without resistors and capacitors. I went through each LED to make sure they all worked, and they did. But when I did it like I show in my schematic, only 2 come on. Actually, none of them came on. I had to take 1 LED out of the board at a time until I found how many could be on. The result was 2 LEDs. Then I tried the capacitor thing. They dimmed out, but didnt dim on. They did this together and not separately (I would probably need to add another capacitor for each LED) Ahh, yes. I used a (standard) 25v, 100uf capacitor and a 10K ohm resistor. I need to use a MUCH less powerful resistor. As for the capacitor, I still have no clue what to use. Ceramic capacitors did absoloutly nothing for some reason. Ranging from .01 uf and 5v through 200 1f 400v. Any thoughts?

 

[thatdecade]

You need a big capacitor, physically the largest one you got. D cell battery sized is what I have in mind. Bigger capacitor, slower charge time.

All the current going to the LEDs has to pass by on the same path that charges the capacitor. That's why you weren't able to light up many LEDs. If our do it right, all of one color will light up, then the next, then the last.
In your drawing, once the capacitor is charged, the LEDs no longer have any current flow (capacitors block dc current when fully charged).

Not sure about the LEDs in series, try parallel, one resistor per led. No resistor on the capacitor, or at least something small. say... < 100 ohms. Capacitor parrellel with the LEDs too, the LEDs won't be able to have a voltage above the caps charge voltage.?..

 

[hobbitdude13]

Ok so I'm going to be mounting headlamps into my Mk. VI helmet. I butchered a led flashlight and the switch said "1.5 a 120v" on it. Now, does that mean I have to use AAAs like the flashlight used, or what?

 

[thatdecade]

hobbitdude, you can safely replace the AAAs with a AA battery pack with the LEDs. Depending on how the flashlight is designed, it will probably heat up a little more than usual running on AA.

The "1.5A 120V" writing on the switch is it's rating. Anything less than the rating is ok. 1.5 Amps, 120 Volts. However, that doesn't mean plug your LED into household 120VAC, that's crazy. Stick to the same number of AAA as the flashlight used. Probably 2 or 3 AAA, so you can replace with 2 or 3 AA for longer battery life and brighter LEDs.

 

[SpartanGirl]

I was thinking of making the green helmet in the second picture for cosplay: http://www.mspaintadventures.com/?s=6&p=006745 I want to know how I could simulate that flashing effect, with the different colours. I want to set it on a timed circuit so the LEDS will alternate colours in the same manner as the picture. How could I do that?

 

[thatdecade]

Sure, you want alternate flashing LED circuit. This circuit is most commonly used to run railroad warning lights.

In the first example, you can speed up the flashing by lowering the part values of the capacitor ( < 10uF) and resistor ( < 100K) that determine the time between flashes. There are two halves to the circuit. One determines the time LED 1 is on and LED 2 is off. The second determines the time LED 2 is on and LED 1 is off. You can find all these parts at radioshack, the transistors don't have to be the exact part value, just NPN type. Do NOT change the 470 ohm resistor, that protects the LED.
http://www.simplecircuitdiagram.com/2009/05/20/led-flasher-using-transistor/

Some other examples
http://www.mrollins.com/flash4.html

 

[SpartanT117]

for arduinos, is there a code I could write for it, like a boot code where the lights just blink and flash in a specific order before it starts the animation?

 

[FatalFetus]

Ok guys I'm really new to electrical stuff and pepakura costume making at all. So I want to wire 2 LEDs to a 9V battery. What resistors do I use? I also plan on wiring a mini fan to a 9V battery for my helmet. What resistor would I use for that?

 

[redwizard3d]

depends on the setup. you need to know what voltage and current draw your led's have. The ones i use are 5v but you can get all sorts of led's. It also depends on if you wire in series or parallel.(side by side or single file). there are a couple of formulas you use to work out what resistors you use.

 

[thatdecade]

for arduinos, is there a code I could write for it, like a boot code where the lights just blink and flash in a specific order before it starts the animation?

Sure, arduino is easy to write for. Blinking a LED is lesson one.
http://www.arduino.cc/en/Tutorial/BlinkingLED

Ok guys I'm really new to electrical stuff and pepakura costume making at all. So I want to wire 2 LEDs to a 9V battery. What resistors do I use? I also plan on wiring a mini fan to a 9V battery for my helmet. What resistor would I use for that?

Use a 500 ohm resistor for each LED and wire the LEDs in parallel (not series). or... follow the advice below

Can use this calculator for more specific numbers and instructions, choose wiring diagram. The numbers it is asking for can be read from the retail packaging your LEDs came in.
http://led.linear1.org/led.wiz

Ponies are only good for one thing... and thats gluing my pepakura together before i resin it

lol, that's awesome redwizard

 

[FatalFetus]

Thanks man That'll help me out alot

 

[SpartanT117]

so time, in arduinos is broken down to thousandths of a second... cool .

 

[thatdecade]

Yep, delay(ms). There are also other delay commands, like microseconds
http://arduino.cc/hu/Reference/DelayMicroseconds

 

[SpartanT117]

I see both of these links are from the arduino site itself, I could probably find all the coding I need there?

 

[thatdecade]

Three is a lot of reference and learning material on arduino.cc, including an active forum. If you want to go beyond that with custom shields and libraries, like the Wave Shield, you'll have to look beyond arduino.cc.

 

[SpartanT117]

ok, thanks! great to have a wealth of information on here! as far as purchasing an arduino, do you suggest radioshack, or the arduino site itself?