/diy/ - Do It Yourself

[Anonymous No.669606]

Hey /diy/, I wanna make a wand (nothing as "extravagant" as pictured) for a cosplay and I needed to make a simple LED light with an I/O button to go on the end of it. Google could tell me how to make a simple LED with a button, but not how to do it without a clunky 9v battery. How would I make this with small round batteries, like AA or AAA or watch batteries and such?

[Anonymous No.669612]

>>669606
bring AAA battery to home depot
go to plumbing aisle
find short length of pvc where AAA battery fits
get 2 end caps

get whatever leds off ebay
get momentary switch like this off ebay http://www.ebay.com/itm/New-Mini-Push-Button-SPST-Momentary-N-O-OFF-ON-Switch-10mm-Red-/321279754705

put some springs inside

mount led on end

wire that bitch up

[Anonymous No.669613]

>>669612
forgot

you'll need a resistor and should make it 3x batteries long

[Anonymous No.669621]

Thanks a bunch dude.

[FatMonty No.669795]

If you're looking for a thinner wand

Go to Dollar Tree and get one of their book lights. They come with a fairly bright LED, 3 button cell batteries, and an on/off switch. It's all pre wired with about 6-8 inches between battery contacts and the LED

[Anonymous No.670115]

>>669795
did you really take a screenshot of a photo

[Anonymous No.670136]

>>669613
> you'll need a resistor and should make it 3x batteries long

2 cells (either 1.5V primary cells or 1.2V rechargeable cells) should be sufficient for red or yellow LEDs. Most green or blue LEDs (this includes tri-color red-yellow-green LEDs) will require 3 cells.

The resistor's value should be at least

(Vs[max] - Vf[min]) / If[max]

where Vs[max] is the maximum battery voltage (e.g. 3V for 2x alkaline cells), Vf[min] is the minimum voltage drop (given in the LED's data sheet), and If[max] is the LED's maximum forward current (again, data sheet).

It should have a power rating not less than

(Vs[max] - Vf[min])^2 / R

where R is the resistor's value.

[Anonymous No.670142]

You need to get an arduino. An arduino micro that's small enough to fit in wand. Use one of the pins as an input for the button and one as an output for the LED.

[Anonymous No.670161]

>>670142
GTFO

[FatMonty No.670221]

>>670115

Maybe... I went to their website and it wouldn't lat me save the fucking picture from my phone

[Anonymous No.670245]

>>669606
>How would I make this with small round batteries, like AA or AAA or watch batteries and such?
if you use watch batteries you don't need a resistor, just a switch
http://donklipstein.com/ledfaq.html#knd

watch batteries have such high internal resistance that they don't heat up much even if shorted. they simply can't put out enough current to burn the LED out. just use small-diameter cells (actual watch batteries, not coin cells) and stack up enough to get the brightness you want from the LED.

also if you get a "membrane" switch, it will be smaller and less conspicuous. basically a pressure-pad-type switch. and cheap too.

[Anonymous No.670262]

>>670245
>also if you get a "membrane" switch, it will be smaller and less conspicuous. basically a pressure-pad-type switch. and cheap too.
Fuck that. Put one of these on your wand. You can name yourself Cedwick Steambottom.

[Anonymous No.670381]

>>670262
Screw that. Go with this.

[Anonymous No.670392]

>>670245
>if you use watch batteries you don't need a resistor, just a switch

you don't "need" resistor, but it is still highly recommend as it will increase your battery life

[Anonymous No.670394]

>>670136
of course you should take to account that alkaline cells should be driven down to 0.8-1.0 volts. make sure you scale your resistor so that you will be getting reasonable amount of current at lower voltages too

[Anonymous No.670397]

You may not need a resistor. The resistor limits the current, but depending on your choice of battery (e.g. button cells), the battery's capacity to produce current may be a sufficient limit.

[Anonymous No.670464]

ITT we discuss far to thoroughly lighting an LED, the most basic electronics project.