Led power and switch help for custom build?

[Rahksi]

Here is a picture of my current cart, and my hilt so far/random switch from lowes.

http://imgur.com/CDLkfWS
http://imgur.com/gM4myTx

My questions are:

Can i use this random switch? It has two prongs, and fits within the hilt without touching, it's close but maybe i can dremel a little off.

What kind of power options should i buy for this led? Are there any that dont require a resistor? I dont mind using batteries, but rechargable would be cool.

Also, for a design/opinion question, would this style switch be off to the side or fit in the middle? What else can i add to decorate the hilt? Im looking for ideas!

Thank you so much for your help.

[Silver Serpent]

You should be able to use that switch. It looks like an ordinary latching style rocker switch.

The amber Rebel LED runs at 3.2v @ 700mA of current. You will need a power source with a minimum of 3.2v to power it. A 3.7v li-ion cell would be ideal. Resistors are easy to work with, and there are a couple of links in my signature that will show you how to find the proper one. Do the math, and we'll be happy to doublecheck it for you.

If you're dead-set against resistors for some reason, you can bump up to a 7.4v li-ion battery pack and the 700mA BuckPuck. It's a more expensive solution, but there's no math involved.

As for switch placement, I recommend holding the saber in your hand. Try to figure out where it would feel natural to have the activation switch. Before you start cutting metal, do a little planning to be sure your internals will fit with the switch in that position. Batteries take up more space than you'd think.

[Rahksi]

Thank you for the reply!

I'm not against resistors, i was just wondering if there were any power supplies in the shop that ran about what my leds needed without need for one. Ill do the math, but would you mind telling me the difference between the dozens or so resistors in the shop?

Im trying to get ideas from other designs, but they are generally sleek designs with only a middle button, or graflex styles. I just want something in between to decorate the hilt a little and make it look more like a lightsaber hilt.

[Silver Serpent]

Different resistors have different Ohm and Watt values. Once you've done the math, you'll get a resistance value (Ohms), and a power value (Watts). Try to find a resistor that matches your values as closely as possible.

Round up.

If you round down the resistance value, you'll run the risk of cooking your LED. If you round down your Watt value, you'll likely blow the resistor (and possibly the LED too). Rounding up is always the safer option. Watts can be rounded up a lot, and won't affect the brightness of your saber. 1 Watt, 3 Watts, 10 Watts, they all function the same. The larger wattage resistors are physically larger, so they'll eat up precious space in your hilt.

[Rahksi]

So if i calculated right. Id need a 1ohms 1 watt resistor?

I got values of .714 for my ohms equation, and .34986 for my watt equation? That's with a rebel amber led (3.7v, 700 ma) and a battery pack: Li-Ion 18500 3.7V 1400mAh.

Also, how do i connect the led to the battery? I see a jst connector for charging...but the batteries are wrapped. I guess i have to cut the wrapping to solder wires to the led?

[jbkuma]

I strongly suggest watching some videos on the TCSS youtube channel. Most of your questions will be answered and you will learn a lot. Madcow does an excellent job with the videos.

The resistor goes in your LED wiring.

[Silver Serpent]

Your resistor value is correct.

Don't unwrap the battery. The JST on the battery is where you will make your connections. You can either get another JST to match up to the battery one, or you can *carefully* cut off the JST and solder your connections directly to the battery. I say carefully because you don't want to accidentally let the pos and neg wires of your battery touch each other. The safest method of doing that is to only cut one wire at a time, and be sure it's heatshrinked before you cut the other wire.