Click here for lightsabers
  • Home
  • Help
  • Login
  • Register
Pages: [1]   Go Down
Author Topic: My First Build (Resistor Question)  (Read 2961 times)
Streen
Knight Apprentice
*

Force Alignment: 8
Posts: 28



« on: November 12, 2016, 12:52:29 AM »

As of now I'm waiting on my order for the parts to build my first stunt saber.  I've done a lot of browsing around for information on how to put it all together, but one thing I want to make sure about is the type of resistor.  From what I gathered so far, I need a 3w 2ohm resistor.

I happened onto this diagram that makes it seem pretty simple...


So my question is, do I have the right information?  Is that the correct resistor?  Is the diagram accurate or maybe over-simplified?

I would greatly appreciate any input at this point.
Logged

scifidude79
8-bit Defender of the Aeon Order
Knight Commander
*

Force Alignment: 2106
Posts: 6326



« Reply #1 on: November 12, 2016, 02:44:54 PM »

Which LED are you using?  Different LEDs have different power requirements.  If you can find out what the voltage requirements are on your LED, you can figure out what resistor you use.  I built my first one the other day using a 2.7ohm 10w resistor, and it works fine.  Though, that was the resistor linked to in the description of the video I was using and I was using an LED with the same power requirements and the one in the video tutorial.  That's not to say that's the right one for you, I'm just saying that's what I used.  I suggest you go to the TCSS (The Custom Saber Shop) channel on YouTube.  They have a video on how to choose the right resistor for your saber.

The wiring diagram is accurate.  It's really that simple.  Though, one thing I did, and this is doer's choice, is put the resistor on the positive (red) wire, not the negative (black) one.  But, Ultra Sabers seems to like to wire their stunts with it on the black, and it doesn't really matter too much.  As long as it's on there somewhere resisting the flow of current along the circuit, you won't blow out your LED.

Logged

Streen
Knight Apprentice
*

Force Alignment: 8
Posts: 28



« Reply #2 on: November 14, 2016, 08:35:00 PM »

I ordered the standard LED Module from Ultra Sabers (Adegan Silver, if that matters) in the electronics section under "Build Your Own Lightsaber".  I just assumed you knew I was talking about that one.

Anyone used this LED before and know what resistor to use?
Logged

scifidude79
8-bit Defender of the Aeon Order
Knight Commander
*

Force Alignment: 2106
Posts: 6326



« Reply #3 on: November 14, 2016, 09:25:41 PM »

I ordered the standard LED Module from Ultra Sabers (Adegan Silver, if that matters) in the electronics section under "Build Your Own Lightsaber".  I just assumed you knew I was talking about that one.


For starters, never assume anything.  Yes, I could have guessed you were using one of the LEDs that Ultra Sabers sells, but you could easily be running an LED from a different source.  And, actually, the color is probably the most important bit of information you could have provided.  White LEDs have a forward voltage of 3.1 or 3.15 volts, depending on whether it's a Cree or a Rebel Star.  (the difference is negligible)  And, they run at 1000mA  Now, I'm assuming you're running the 4AAA battery setup.  AAA batteries are 1.5 volts, therefore you get 6 volts with four of them.  Armed with that information, you can calculate the resistor you need.  There's a simple equation to figure this out.

R=V/A (Resistance = Volts / Amps)

So, 6 volts - 3.1 (to be safe) volts is 2.9.  1000mA = 1 amp, so you divide 2.9 by 1 and it comes back out to 2.9.  So, you need a 2.9 Ohm resistor.  For wattage, you can go with a 3 or a 5 watt resistor, since that's basically just the heat dissipation of the resistor.

Now, does that mean that's what Ultra Sabers uses?  I don't know, I don't have a white (silver) LED saber.  I just used a simple calculation to figure out what it will probably run on.  Resistors aren't an exact science.  For example, your forward voltage (3.1v) is a variable number.  It's not necessarily going to consistently run at that voltage.

For the build I did recently, I used a royal blue Rebel Star LED that says it runs at 3.2 volts.  I'm using a 2.7 Ohm resistor and it's working just fine.

Anyway, that's what I have.  Take it or leave it.  You can wait for someone who has an Adegan Silver stunt or saber with Obsidian Lite that feels like taking it apart to weigh in if you want.  (Obsidian premium sound uses a buck puck, so that won't help)
Logged

JediXIX
Alchemist of the Sentinel Order
Knight Commander
*

Force Alignment: 1172
Posts: 2190



« Reply #4 on: November 15, 2016, 02:13:37 AM »

Excellent advice SFD . . . points Bro  Smiley


Technically a resistor is matched to the Battery & LED forward voltage as mentioned . . . here's a good online calculator to use http://led.linear1.org/1led.wiz

For their sabers that use a resistor, US use a best average standard resistor that works . . . for ALL the 4xAAA US hilts I've dismantled, every one regardless of LED module colour has a 3w 2ohm resistor to the negative wire . . . this makes it possible for US to offer the Quick Disconnect feature so any module they sell will just connect to the battery / resistor setup . . . It also means that just about anyone can change their LED colour if they want to, by ordering a spare LED module from US and installing it themselves without blowing the LED (as long as they keep the standard resistor in place) . . .

Just for reference, the resistor used in their 7.4v Li-Ion setups is a different spec . . . or, a 1000ma BuckPuck if optioned . . .
Logged

Remember... The Force will be with you... Always . . . (Just let it in)

Lord Canterbury
Dark Knight of The Scorpion Order
Knight Commander
*

Force Alignment: -1313
Posts: 1972


Fish Fingers & Custard


« Reply #5 on: November 15, 2016, 02:34:36 AM »

Excellent advice SFD . . . points Bro  Smiley


Technically a resistor is matched to the Battery & LED forward voltage as mentioned . . . here's a good online calculator to use http://led.linear1.org/1led.wiz

For their sabers that use a resistor, US use a best average standard resistor that works . . . for ALL the 4xAAA US hilts I've dismantled, every one regardless of LED module colour has a 3w 2ohm resistor to the negative wire . . . this makes it possible for US to offer the Quick Disconnect feature so any module they sell will just connect to the battery / resistor setup . . . It also means that just about anyone can change their LED colour if they want to, by ordering a spare LED module from US and installing it themselves without blowing the LED (as long as they keep the standard resistor in place) . . .

Just for reference, the resistor used in their 7.4v Li-Ion setups is a different spec . . . or, a 1000ma BuckPuck if optioned . . .


Point for that one . . . . I stripped my Menace CE with Basic Sound a while ago for a complete overhaul and noticed that resistor on it but didn't know the details . . . .
Logged

Winning? Is that what you think it's about? I'm not trying to win. I'm not doing this because I want to beat someone, or because I hate someone, or because I want to blame someone. It's not because it's fun. God knows it's not because it's easy. It's not even because it works, because it hardly ever does. I do what I do because it's right! Because it's decent! And above all, it's kind! It's just that. Just kind.


~ The 12th Doctor in "The Doctor Falls"

scifidude79
8-bit Defender of the Aeon Order
Knight Commander
*

Force Alignment: 2106
Posts: 6326



« Reply #6 on: November 15, 2016, 02:45:22 AM »

I took apart a couple of my Utlra Saber stunts earlier to do color swaps.  One had Sentinel Yellow and the other had Fire Orange and both had 2 Ohm 3w resistors.  Well, obviously, the good folks at Ultra Sabers know what they're doing.  So, you may be able to get by with one of those.  *shrugs*

Excellent advice SFD . . . points Bro  Smiley


Technically a resistor is matched to the Battery & LED forward voltage as mentioned . . . here's a good online calculator to use http://led.linear1.org/1led.wiz


Point back at you, JediXIX.  I didn't know about that online calculator.  That suggests a 3.3 Ohm 3W resistor for the 3.1v 1000mA setup.  Interesting.  Of course, that may be for a regular LED, not something as high power as a Cree or Rebel Star.  Still, it never hurts to err on the side of caution when it comes to this type of thing.  Better having too much resistance than blowing out a $35 LED module.  Wink  Your blade just won't be as bright, but the resistor can be more cheaply replaced.
Logged

Andel-Thön
Force Sensitive
*

Force Alignment: 1
Posts: 4



« Reply #7 on: June 10, 2018, 10:48:10 PM »

As of now I'm waiting on my order for the parts to build my first stunt saber.  I've done a lot of browsing around for information on how to put it all together, but one thing I want to make sure about is the type of resistor.  From what I gathered so far, I need a 3w 2ohm resistor.

I happened onto this diagram that makes it seem pretty simple...


So my question is, do I have the right information?  Is that the correct resistor?  Is the diagram accurate or maybe over-simplified?

I would greatly appreciate any input at this point.


Thank you for posting this. Do you have a diagram for a saber with sound? I assume its just adding the sound board and speaker correct?
Logged

Single Grey-Jedi Knight
Saber enthousiast
Blaster enthousiast
Land speeder mechanic
Survivalist

Kagetsume
Knight Apprentice
*

Force Alignment: -18
Posts: 25


« Reply #8 on: June 10, 2018, 11:19:40 PM »

Thank you for posting this. Do you have a diagram for a saber with sound? I assume its just adding the sound board and speaker correct?

Wiring a saber with sound is quite a bit more complicated, depending on the sound board you choose to use and your goals.  I've wired up Obsidian V3, V4, and Igniter 3 boards before.   What do you intend to use?
Logged

tx_tuff
Knight Commander
*

Force Alignment: -1075
Posts: 4020



« Reply #9 on: June 11, 2018, 10:55:04 AM »

First let me say I'm not trying to be rude. Now if you plan on doing wiring, changing LEDs, adding sound boards, building your own saber, etc... Don't just get online and ask questions. Do research, when you think you have a pretty good idea do more research! After doing research, and doing more research, then you can ask questions.

I know this because I wanted the same, just a simple answer. But there is no simple answer. You want to get these things right the first time so you don't have to go back and fix things.

Which LED to use, which resistor to use (the online calculator is great), what battery set up matters too, what kind if soldering iron, wire, and flux to use. It all factors in.

Sent from my XT1650 using Tapatalk

Logged

Dauntless Seven
Lady of the Sage Order
Knight Commander
*

Force Alignment: 2037
Posts: 5444



« Reply #10 on: June 11, 2018, 01:33:40 PM »

This thread is from 2016.  At the time all of the members whom made a reply were just starting out with their saber electronics conversions.  All have improved greatly with both experience and knowledge.  Some of this information still stands.  Also there is now excellent how to tutorials on YouTube from fellow saber enthusiasts, customizers and sabersmiths.  For example that is how I learned to solder watching multiple different techniques and suggestions.  Then asking members what their choice was and if my kit/iron was a good enough quality.           

For me asking for assistance on an online lightsaber Forum is a good start and even finish for accumulating pertinent research that agrees with what one finds elsewhere.  If not absolutely sure or confident don't do it unless one is prepared to make any mistakes part of the learning curve... even costly ones such as a blown soundboard or speaker. Those with all the talent and experience that they need still make silly errors.  Smiley
Logged

Pages: [1]   Go Up
Send this topic | Print
Jump to: