2010 Electronic Lightsaber w/ DVD Tutorial

[Matt Thorn]

Rhyen! That did the trick! I don't know whether to hug you or kick you for not telling us earlier. Even with the BD242 transistor and 4 AAA alkalines, I'm getting about 1180 mA, which is plenty. Thanks!

So, again, here is the proven wiring diagram again:



I am pleased as punch about this. Hopefully I can finish this saber today and send it off tomorrow.

I'm also looking forward to seeing what kind of results we get from the even higher-output transistors.

Edit: I measured it with two and one negative leads. With two negative leads connected to the base of the transistor, the collector put out 1010 mA. With just one, it put out about 745 mA. Still plenty of wiggle room one and maybe even two accent LEDs.

P.S.: I've decided to use this set-up with a green Seoul P4 and a 1.5 Ohm, 1-watt resistor, using two negative leads for the main LED and leaving one for an illuminated switch.

[Skottsaber]

Matt, I see you're not using a recharge port. Now obviously you can't recharge alkalines, but what about killing power? Does this board not suck much juice when idling?

[Rhyen Skytracker]

Hey, what can I say? It seemed to me that the collector would collect the power and the emitter would be the output to release the power. How would I know that it would work oposite? Oh, that's right. I am "special" and have to do everything backwards. LOL I guess when I did my first one I used my "psychotic powers" and not thinking I wired it backwards and got great results. LOL

[Matt Thorn]

Matt, I see you're not using a recharge port. Now obviously you can't recharge alkalines, but what about killing power? Does this board not suck much juice when idling?

Since this is for a 13-year-old who's never owned a lightsaber before, I'm trying to keep it as simple as possible. I think these toy sabers drain very little when idling. I have an old toy saber that has been lying around for well over a year with the batteries inside, and it still fires up.

Thanks to some generous help from a new friend here on TCSS, I will soon be getting five more 2010 toy saber boards, and they will no doubt be put to more elaborate use. Now that the problem of current has been ironed out, this has instantly become my favorite "can-actually-be-acquired" board. I even prefer it to a Force FX board, because of the cost, size, and ease of use. Until the TCSS board comes out, I will be quite happy with this board.

[Rhyen Skytracker]

I am glad my backwards thinking ways could help. Feel free to contact me when ever you need more illogical thinking. LOL

[Matt Thorn]

Hey, what can I say? It seemed to me that the collector would collect the power and the emitter would be the output to release the power. How would I know that it would work oposite? Oh, that's right. I am "special" and have to do everything backwards. LOL I guess when I did my first one I used my "psychotic powers" and not thinking I wired it backwards and got great results. LOL

Well, thanks again to you and your psychotic powers. I should have known better myself, but my previous experience was with NPNs, and I was basically at sea here.

P.P.S.: It occured to me that, instead of using one or two of the existing negative leads for accents LEDs, it would be more efficient current-wise to have all three go the transistor, then wire the accent LED in parallel between the transistor and the main LED. Because the transistor multiplies the amount of current going into the base of the transistor, the amount of current lost when one wire is removed is also multiplied. But on the other side of the transistor, the accent LED draws just 20 mA from the total, so your main LED should get about 1160 mA, instead of the 1010 mA it would get if you use one of the negative leads from the board. Does that make sense? Anyway, I tried it, and it looks good so far. (Knock on wood.)

[Rhyen Skytracker]

That is one thing I have ALWAYS done since I was a kid. I will always try every option and very rarely give up. I knew that since the transistor and economy sound board were not that expensive, that I didn't have much to lose if it did fry the transistor or sound board Your post have helped me out on several occasions so I am glad I could repay the favor. I guess we need to have all of the diagrams in this thread updated so people won't have to go through what we went through.

[Noyl Wendor]

It depends on how much voltage is actually going to the LED, what the forward voltage for your LED is, and how much, if at all, you want to over-drive it. First, measure your voltage. The multimeter is your friend. Then check out the handy Resistor/LED Charts that newcomers all seem to overlook. Rule of thumb: you are more likely to need a resistor if you are using a red/orange/amber LED than if you are using a green/blue/cyan/white LED.


Living in Japan, I don't know beans about RS, other than that it has one foot in the grave. (See earlier post.) "The Google" is your friend. "TIP42" and other transistor numbers we give here are generic names for transistors of certain types, and are manufactured by many different companies (mostly in China, using children who are chained to the assembly line and force-fed lead and mercury twice a day). So using these numbers to find the transistor you need is easy. Unless you live in North Korea. In which case you wouldn't be participating in this forum. Unless you were a government agent.

If you can do without one, yes. See above.

Like I said, it depends on all those different factors.

After typing all this, I noticed that you have been a member since 2006. No offense intended, but, based on your questions, I thought you were a newcomer.

No offence taken, its not like I have a degree in electrical engineering. Or am one of those smart pretentious types. Oh yeah and having been here since 2006 I'm just getting into doing sound. As you pointed out the multimeter is my buddy, oh and the handy resistor chart thingy that says what I can and can't do with my forward voltage.
Thanks for the subtle flameage.
I'll just keep reading, and keep my Q's on the qt.

[Rhyen Skytracker]

P.P.S.: It occured to me that, instead of using one or two of the existing negative leads for accents LEDs, it would be more efficient current-wise to have all three go the transistor, then wire the accent LED in parallel between the transistor and the main LED. Because the transistor multiplies the amount of current going into the base of the transistor, the amount of current lost when one wire is removed is also multiplied. But on the other side of the transistor, the accent LED draws just 20 mA from the total, so your main LED should get about 1160 mA, instead of the 1010 mA it would get if you use one of the negative leads from the board. Does that make sense? Anyway, I tried it, and it looks good so far. (Knock on wood.)

That is the way I do it. If I use illuminated switches or accent LEDs I wire them after the transistor. The output directly from the board is not really enough to make an accent LED bright at all.

[cardcollector]

I guess we need to have all of the diagrams in this thread updated so people won't have to go through what we went through.

I am working on that, then I am going to clean up the first post so you don't have to read all 10 pages of this thread...

Great job Rhyen! I am impressed at your determination.