Toroidal Power Amplifier

[rave154]

@ dragon,

your piccy is almost identical to what i setup, except my toroid are a little smaller

@ Scratch,

good find with that video ( ive searched & searched youtube for "toroid, coil, core" etc and missed this one ) but he seems to be showing exactly what i said, that the output is the same no matter "where" the 'secondary' is in relation to the toroid ( as long as its going 'around & through' it of course ).

p.s just watched a couple of his other videos and from them i would say its a fair bet that he has read the same pdf's that are mentioned in this thread.

[rave154]

@ nil,

do you have access to pulsed DC at all? Either in the form of a 555 circuit or function gen, connected to a mosfet circuit? As i found that this gave a greater output ( and will make for easier input energy calculations )

[nilrehob]

@ nil,

do you have access to pulsed DC at all? Either in the form of a 555 circuit or function gen, connected to a mosfet circuit? As i found that this gave a greater output ( and will make for easier input energy calculations )

Yes, its on my list

/Hob

[rave154]

nil,

great !!

cant wait to see some videos !

i just took apart a shaded pole motor from a micro wave oven to get the core of sheeted silicon steel ( i believe ) which actually makes a reasonable toroid about 60mm diameter...not sure if the direction of the grain is going to come into play though as it might be in the wrong direction for a toroid winding.

anyways i took some plastic coated wire from a pc power supply, fairly thick stranded wire, about 8-10 turns....same input as before...very small output.

nil, have you done any more testing with your two toroids? btw where did you get then..and at what cost?

[dragon]

A closed "E" or "C" core will work equally as well as a toroid and is easier to wind the coils. There is no difference in performance and/or how the A field in the center acts. The B field is the flux within the core of the toroid or transformer, the A field is within the center of the closed magnetic circuit or hole as it were. So to recap... a closed transformer core is the same thing as a toroid.... the only difference would be the frequency range of the core material.
________
Montana Medical Marijuana Dispensary

[rave154]

thanks dragon, ive just spent about 40 minutes searching for a supplier of U & I cores....... very hard to find at a reasonable cost

any household items or whatever that they can be salvaged from ?

[dragon]

TV flyback cores, microwave transformers - anything that has a transformer... I believe electronics goldmine has the flybacks for 4 bux each, they also sell the E cores with keepers. Coat hangers work for making toroids and/or cores for coils....
________
NEW MEXICO DISPENSARIES

[rave154]

ok i just tried my motor core toroid wrapped with about 300 turns of 28SWG , linked by 10 turns of 22SWG to the small toroid(that has worked nicely in the other tests ) which has 38 turns on it.

very small output , i also tried it backwards, same result.

[rave154]

I just re-arranged things,

i have the same 2 small toroids each with 38 turns, this time linked with only 8 turns of 22SWG...

4.9V pulsed DC @ 50% input

9.9V RMS , 28V peak-to-peak , sine wave

interestingly.the frequency that gives the best output is only 913 KHz and not the 1.038MHz from the earlier test

[dragon]

Both coils will resonate at different frequencies so the outcome will be poor. You may have to use caps to match the resonance between them for good results. ( LC circuits ). Find the resonant frequency of the input and match the output coil with a cap...
________
Big naturals

[rave154]

just tried something to check wether its the number of turns of copper that link the two toroids....or the "amount" of copper...that changes the output.

using the same two 38 turn toroids...they were linked by two seperate lengths 22SWG copper approx 8 inches long but curled into a circle.

having 1 loop shorted gave 2.9V RMS and around 8V peak-to-peak, then shorting the other loop too ( but still a seperate loop )....gave an increase in both voltages..... however.....having only 1 loop shorted but looped through twice.....gave no increase in voltage.

Would this indicate that it is the amount of copper rather than the amount of turns that "couples" the two toroids more completely?

p.s

i just tried 3 lines of power supply line linked as each end so as to make a 3-stranded cable so to speak.... when looped through the toroid twice (as opposed to just once ) it produced an increase.....where-as the two seperate loops of copper as above did not produce an increase over just one copper loop.

*confused*

[dragon]

I found that linking them with a heavy copper cable produced the best coupling. That link has to carry a significant amount of amperage at low voltage to energize the second core. If you connect a low voltage bulb to that link it will light quite nicely while carrying current to the second toroid.

Here is another way to use the same arrangement with a toroid and a copper ring set to resonance...

http://www.energeticforum.com/attach...scillator2.jpg
________
STARCRAFT 2 STRATEGIES AND REPLAYS

[dragon]

Here is a link that helps to explain the phenominum a little better in bare bones basics.... SCIENCE HOBBYIST: Right Angle Circuitry .
________
Exteme q vaporizer

[rave154]

Dragon,

i remember reading that page possibly a year ago, it didnt even pop into my mind while i was reading the other two pdf's....shows how much you can forget eventually

[rave154]

Hi,

see attatchment,

FG = function generator, set to 5V pulsed DC @ 5.0V

Resistor (acorss cap) is 100 Ohm.

The Blue loops is actually a piece of multi-stranded copper wire ( from a power supply ) and is looped through all three toroids 3 times.

When W-2 is open, current draw into W-1 is 46.4mA and voltage across resistor is 22mV

When W-2 is shorted, current draw stays at 46.4mA and voltage across resistor goes up to 127mV.

However, im assuming the function generator has some sort of current limiting built in....so it may be that upon shorting W-2 the current draw "tries" to rise but cant due to the current limiting in the function generator?