My first LED string blade - a progress diary

[parsaver]

I'm going to build one.... this thread has incepted the idea. I've got 2 more projects lined up then its a LED blade. I haven't seen a really bright one in Red...maybe ill give it a shot.

[Obi1]

The completion:

I left off at the stage where I had the full LED string, it lighted up all right, it had got its first protection and diffusor layer in the form of a shrink tube I heated - for lack of a heat gun - the shaft of my soldering iron.


My next step was to scavenge a proper board for this build. I Long planned to hack an Ultimate Hasbro board for one of my custom builds, more out of curiosity than anything else. Challenges and boundary conditions:
- the string blade uses around 6.8V, the Hasbro can take up to bit above 5V
- I'm not particularly fond of resistors, I like active drive adjustment better. So I had to solve supplying the blade with a variable voltage out of 2 18650 Li-Ion cells no be able to Limit the current and also decrease the light intensity if I let the Kids play with the blade (yeah, I do let them play, and yeah, the blade is infernal bright, and Kids are mesmerized by brigth blade and tend to look at it for long minutes...)
- I had to Bypass the Hasbro Output stages because of the different voltage used by the blade and due to fear of frying it

So I put together this circuitry>


Now back to the main character of this diary: the blade. Although it had some mechanical stability provided by the shrink tube, I figured it might be inadequate to protect it during a (less violent) duel. Just by sheer luck I got a huge sheet of cellophane packaging material I had been looking for for ages in vain, when we bought a new desk for my son (he's going to School soon ) . I wrapped this 2nd line of defense around the string:


I was a bit afraid that with 4 diffusor layers the intensity will vanish, and while so many layers do decrease the intensity, it's not that bad. Even though I used thin angle LED's, the light is absolutely even. I have only minimal shadowing due to the wires, you have to look very close to see them (which I would respectfilly discourage you to do for obvious reasons...)


I used a DIN 8-pole plug, female side for the blade, male for the hilt side. Amazing thing is: the winded section fits perfectly into the TCSS diffuser!!! It's plug-and-play.


Next steps: Cram-fu the custom electronics along with the Hasbro board into the hilt, plus the 2 serially connected 18650 batteries. Oh yes, and to wire a clash sensor.

And finally the video showing the blade in action (sorry for my lousy English):

[Zeni]

Hi Obi1,
really a nice job, as a total noob I'm sincerely impressed.
Most of all, I'm interested in understanding your custom circuit to bypass the hasbro soundboard. I have a fx soundboard and I wish to build a led-string blade, but I'm stuck because I'm not so able as you are in electronics. So I have the same power problem you solved in that way...
Thanks for any info and please excuse my approximate english...
Zeni

[Obi1]

Bongiorno Zeni,
Thanks for you post, I've been thinking about drawing the schematics for this circuitry for a long time now, you gave me just the right kick to start with it. I will open up for that a separate thread, and I will post the link here, so watch out (I'll try to do it during the weekend).
Ciao!

[Zeni]

Many thanks Obi1, it's so important to me to see people sharing any useful knowledge! I just hope I'll be able to help someone sooner or later, this forum gave me so much...
Ciao!