Make a Joule Thief

Step 3: Solder it all Together

Now we are going to solder the whole thing together. You could put it on a board if you like, but in this Instructable, we're going to free-hand solder it. Or whatever you call it. You can follow these written instructions, or take a look at the pictures. They explain it very well.

First, take the two outer leads of the transistor and bend them outwards a little ways, and bend the middle lead backwards. Bend the LED's leads outwards, too. You don't have to, but it makes it easier to solder.

Take one of the wires coming from the toroid that is alone; that is, not twisted together with another wire. Solder it to one side of the resistor. Solder the other end of the resistor to the middle lead of the transistor.

Take the other single wire from the toroid, and solder it to the collector of the transistor. Solder the positive side of the LED to the collector as well, and solder the negative side to the emitter.

All that's left to do now is solder an extension wire to the negative side of the LED. Take a piece of that wire you had earlier and solder it to the transistor's emitter.

Comments

[Indula]

can we use button cell

[rstevens76]

I'll 2nd that - it'll explode. I've tried numerous times to solder button cells, sometimes I get away with it (and I'm a fairly decent solderer), but probably 80% of the time it'll explode. Of course, it usually doesn't cause any damage, just a loud pop and you'll need to change your undershorts!

[chitkaran]

Why dont u try using a Button cell holder.. ???

[zstein]

Cause "Cowboy electricians" think everything should be soldered directly onto... You're exactly right, that's why they make button cell holders.

[1up]

Sure, but don't solder to it. I can almost guarantee you it will explode.

[Gepetto Father]

i've soldered button cells many times with no explosions involved. What does happen is the fast oxidation of the metal case, specially where i sand to get a cleaner sodering surface.

Of course, don't take too much time soldering it or it really might explode. Other thing to note is that they stay hot for like, centuries, after you heat them.

[PatrickVallieres]

i us a button cell and a hollther from a old computer and a micro swech

[robot1398]

how thick wire we have to use to wind on the toroid

[metroid62]

Ah yes, I'm about to get the parts for this, I'm excited because this is going to be my first minor project that involves batteries and LED's.

[macman808]

same here i found that i can get all the parts for $4.86 from my local jaycar

[Jimmy Proton]

thats a lot more than i would pay for some thing like this

[dhoi]

not working

[_Scratch_]

in order on the transistor isn't it Emitter, collector , base.........not emitter, base, collector? just wondering, im just starting to learnabout this stuff.

[1up]

It really depends on the transistor it is. For this one, look in the first picture. From top to bottom it's collector, base, emitter. Just follow the pictures for the soldering and it'll be easy.

[Estwald]

Some call this the "dead bug wiring" method of circuit assembly.