3v OU Flashlight

[lost_bro]

Hello All:

OK, trying to figure this out.


*Ferromagnetic Resonance is also called spin precession resonance.

*The loss factor, which is the normalization of loss tangent per unit of permeability, is a material property describing       the loss characteristics per unit of permeability.

*This remains true so long as the increase in height/length does not cause the core to be in dimensional resonance.


Dimensional Resonance is *DIFFERENT* from Ferromagnetic Resonance (spin precession resonance).


take care, peace
lost_bro

[gyulasun]

Well, using the formula with cm as units gives me 29. And using mm as units I get 2.9. (I used 50 mm for OD and 25 mm for ID).

Are these Hz? Cycles per microsecond? What did I do wrong?

From the slide:

F_MR = 5700/(3.142 * ((10 * OD) + ( 10 * ID)/2))

Hi TinselKoala,

I recall a similar formula which originally was given in a data sheet by Philips (acquired later by Ferroxcube) and the core material was 3R1 with square loop (nearly rectangular hysteresis loop) feature also for MnZn ferrite material.  However that formula from Philips did not include a 10 times multiplier in its denominator, and there seems to be a parenthesis shift at the end too in the formula you were given, see the Philips formula in Page 8 of the attached file.   

With your OD=50mm and ID=25mm, the mechanical resonant frequency for the core comes as 48.4 kHz from the Philips formula.

Maybe tuning the core to this frequency could give something useful...

Gyula

[lost_bro]

Hi TinselKoala,

I recall a similar formula which originally was given in a data sheet by Philips (acquired later by Ferroxcube) and the core material was 3R1 with square loop (nearly rectangular hysteresis loop) feature also for MnZn ferrite material.  However that formula from Philips did not include a 10 times multiplier in its denominator, and there seems to be a parenthesis shift at the end too in the formula you were given, see the Philips formula in Page 8 of the attached file.   

With your OD=50mm and ID=25mm, the mechanical resonant frequency for the core comes as 48.4 kHz from the Philips formula.

Maybe tuning the core to this frequency could give something useful...

Gyula

OK,  just to clarify from the attached PDF file posted earlier:

take care, peace
lost_bro

[Vortex1]

Took a few hours to build this Akula dual 494 switcher. I tested both channels independently with dummy resistor loads.

Channel 1 Frequency range around 13 kHz to 400 kHz, duty cycle control, 0 to 45%

Channel 2 Frequency range  around 26 kHz to 800 kHz duty cycle control 0 to 90%

With five parameters and such wide adjustability, it would seem difficult to hit the sweet spot.

I used ten turn trimmers for good resolution of setting.

Note that one of the trimmers, the 10k hooked to pin 1 sets the voltage shutdown level.

Core and coil testing is the next phase.

Regards, Vortex1 aka ION from Overunityresearch.com

[TinselKoala]

Took a few hours to build this Akula dual 494 switcher. I tested both channels independently with dummy resistor loads.

Channel 1 Frequency range around 13 kHz to 400 kHz, duty cycle control, 0 to 45%

Channel 2 Frequency range  around 26 kHz to 800 kHz duty cycle control 0 to 90%

With five parameters and such wide adjustability, it would seem difficult to hit the sweet spot.

I used ten turn trimmers for good resolution of setting.

Note that one of the trimmers, the 10k hooked to pin 1 sets the voltage shutdown level.

Core and coil testing is the next phase.

Regards, Vortex1 aka ION from Overunityresearch.com

Good that you did it that way, it gives me a better idea for my own layout, which I'm starting to build.

Some questions if you don't mind.
1. What specific exact schematic did you use?
2. I see you are Miller-clamping both mosfets. What PNP transistors did you use here?
3. And... do you really really think you are going to need those large heatsinks? Let's see.... if a 9v battery is capable of supplying 9 amps into a dead short for a few minutes...  wow. You must be expecting some pretty serious overunity to need those big heatsinks.
4. What mosfet part number are you using? I will be starting with IRF3205 I think, which has such a low Rdss that it probably won't need a heatsink even with 9 amps DC flowing through it.

The device is supposed to use LEDs for the "load" isn't it? LEDs are very non-linear, they behave nothing like resistors. Your load resistors aren't going to give you a proper idea of the circuit's operation or performance.

I was expecting one of the 494s to have a much lower operating frequency.



How are you going to get batteries into those tiny trimpots? I think Akula is probably using button cells inside two of his potentiometers.