Joule Thief

[electricme]

@All
i am still asking myself witch way i should go.

mechanical rotary switch
using a motor to turn it.
the switch would have to be custom made.

i could probably use multiple brushes around a flywheel that have only one contact.
that contact would be connected to the shaft and a brush used to pickup the output.
a mk8 would require 16 separated brushes, connected to the 16 caps separately.

someone have other ideas on how to easily make such switch ?

Hello TheNOP,

A mechanical rotary switch could be made from a comutator from an armature from any generator (not alternator) electric drill, grinder etc etc.

Remove every second brass contact the brush usually makes contact with, be careful you don't dislodge the ones nexto it.
Then fill the space with epoxy 2 pack that will harden to a glass finish, put this modified armature in a lathe and turn the whole lot to a smooth finish (I used to do this as an autoelectrician), then ressamble.

I forgot to mention to remove all the windings, after that, solder a wire link to the oppersate communitor bar pieces so the armature brushes can make continunity.

BTW, armatures are designed to be spun at very high speed, and make millions and millions of mechanical contacts.
Drive this with a electric motor using PWM control circuit, to give you a speed contril.

hope this helps.
jim

 

[xee2]

@ dog812

Any ideas how i can make it work better? Or get more LED's of differnt colors / voltages in there? Usually i like to use etleast 7 different colors, 3 of each.. = 21 in total.

Not all LEDs turn on at the same voltage. When you put an LED that turns on at 3.0 volts in parallel with an LED that turns on at 3.5 volts, only the 3.0 volt LED will turn on. This is because as soon as the lowest voltage LED turns on it hogs all of the current and the voltage will never go higher than what that LED needs to stay on.
If the LEDs are in series this problem does not occur.

[jeanna]

Dog812,

Did you see my post from earlier today?

It is on page 480. Look at the 3rd picture and get that toroid. It fits into the AA battery holder and I wound a secondary I remember only 20 or 30 winds with red radio shack mag wire. It lit all 30 of my bright white leds. They were in a parallel arrangement. that is, just as jadaro just described, as though all the long legs were taped together and all the short ones together. each wire which is the end of the secondary goes to one leg of the led pack. Try it with one then 3 just to get the concept.

You want to persist on this one. It is the way to go for sure

allelectronics part# TOR-23, 10/$1. 10 cents a piece. It is a very good deal. Mag wire is great but you must sand the varnish off right? It is great for your application because it is so very thin.

try it again,

jeanna

[dog812]

I dont see how you wound 20 or 30 secondarys in that pic??
maybe i dont understand ?

you wind 2 wires together to make the JT , that is the primary , correct?
Then you take a second single wire, and wind it.. that is the secondary, correct?

In your picture all i see is the pair of wires winded together?

[jeanna]

you wind 2 wires together to make the JT , that is the primary , correct?
Then you take a second single wire, and wind it.. that is the secondary, correct?

I'm sorry dog812, the pic is too blurry. If you look carefully you will see a shininess around a lot of the red in the center of the toroid in the bottom pic. That is the very thin red varnish coated mag wire. It is so thin that it is easy to pull it tight when winding it as secondary and really bury it in between the primary wires. Yes, you are correct about the wires. It is just a lousy picture.

I was busy with my latest tests and didn't get back to you. Sorry for that. It probably looked rude.

jeanna