View Full Version : Issue with LED and Transistor

03-17-2017, 04:57 PM
I have everything wired up correctly. When I hit the switch the sound comes on. Swing/Clash is working fine also. The issue I'm having is the when I plug in the battery, the LED'S come on, and the transistor starts getting really hot. Using the switch doesn't shut them off. I can't see any spot where they would be short circuiting. I'm using the Luke Skywalker BladeBuilder board with the tri-cree LED, a 18650 battery, and a TIP42G transistor. Any ideas?

03-17-2017, 05:28 PM
Okay, so I did a little troubleshooting, and I'm finding that the issue is the connections for LED's on the board. They're not stopping the current.

03-17-2017, 05:31 PM
If I wire the LED- to the speaker, that seems to work perfectly. Is that okay?

03-18-2017, 07:43 AM
Yes that's one of the way many have done it. It is a good way to get the flicker effect.

03-18-2017, 07:50 AM
Are you sure you had your transistor wired correctly in the first instance? I've never had it even get warm.

03-20-2017, 07:41 PM
As far as I could tell it was wired correctly. Gate to LED- on board, collector to LED+, and Emitter to Battery+. I had everything working but unfortunately I couldn't get it all to fit in the hilt. I elected to go without sound instead. It looks fantastic so I'm fine with it.

03-20-2017, 07:45 PM
If you are happy with it, that's all that matters.

Here's a peak at what I crammed into my hilt: http://forums.thecustomsabershop.com/showthread.php?20243-JB-s-Pathfinder-Scratchbuild/page4

03-21-2017, 08:35 AM
I have had chinese knockoff transistors tip42c get warm.

Usually its from shorting two of the legs if it is genuine. I couldn't get enough juice to power an LED fully from the speaker on the Rey Bladebuilder. It might be from the transistors I am using.

You could in theory wire up two led Die one from the speaker ground and one from the Original LED ground.

It is pretty fun upgrading the toy soundboards. I recommend installing a better speaker as well.

JBkuma, That's some cramfu skill , All of that and a crystal reveal? All the beautifull electronics in the core deserves a little better than a pvc hilt though. I hope to finally flash a bootloader onto my arduino clone. Its a bit tricky.