3v OU Flashlight

[avalon]

http://www.overunity.com/14610/akula0083-light-no3-dual-tl494/

[d3x0r]

http://www.overunity.com/14610/akula0083-light-no3-dual-tl494/

that's not really the same...
MC35blahblah or dual tl494 ... or lasersaber jouleringer extroidinaire something

but regarding your scope and resonance, you said ti was a combination of frequencies... so if you change the yellow while the blue is making a spikey red... so you gain/lose spikeyness?

[gyulasun]

Hi Lost_bro,

you wrote:

Appears to me that the center screw  plays a very serious role in the overall equation of operation. 

I think the role of the center screw is to fix and hold the two pot core halves together.
When you have no any pot core around the bobbin or they are around but the facing halves
are not firmly tightened (i.e. there is air gap betwen them), all this means the inductance of the coil(s)
on the bobbin is not sufficiently high enough for a specific job. By using the pot cores you increase
the inductance to the max possible the pot cores are designed to give and / or to achieve an inductance
value which is already sufficient for the task.

Yes the metal screw influences the inductance of the coils on the bobbin via the pot cores like
a tuning slug core does because it possibly has a u > 1 permeability (unless it is stainless steel
with a u around 1).
But remember that a metal screw can introduce eddy current loss which may not be harmful in this application
but can be in other circuits like narrow band (high Q) LC filters. In the latter case nonmetal fixing means are used
via the through-hole of the pot cores or they are simply glued or clamped together from outside.

Gyula

[avalon]

that's not really the same...
MC35blahblah or dual tl494 ... or lasersaber jouleringer extroidinaire something

but regarding your scope and resonance, you said ti was a combination of frequencies... so if you change the yellow while the blue is making a spikey red... so you gain/lose spikeyness?

Pay attention, man. I was referring to the dual-TL494 schematics posted by tarakan.

~A

[lost_bro]

Hi Lost_bro,

you wrote:
I think the role of the center screw is to fix and hold the two pot core halves together.
When you have no any pot core around the bobbin or they are around but the facing halves
are not firmly tightened (i.e. there is air gap betwen them), all this means the inductance of the coil(s)
on the bobbin is not sufficiently high enough for a specific job. By using the pot cores you increase
the inductance to the max possible the pot cores are designed to give and / or to achieve an inductance
value which is already sufficient for the task.

Yes the metal screw influences the inductance of the coils on the bobbin via the pot cores like
a tuning slug core does because it possibly has a u > 1 permeability (unless it is stainless steel
with a u around 1).
But remember that a metal screw can introduce eddy current loss which may not be harmful in this application
but can be in other circuits like narrow band (high Q) LC filters. In the latter case nonmetal fixing means are used
via the through-hole of the pot cores or they are simply glued or clamped together from outside.

Gyula

Good day Gyula

Yes, I understand the necessity to firmly clamp the ferrites together in relation to the inductance generated......

But,  the interesting note to the situation is that the metal screw not only passes thru the POT core but is fastened with threads to what *appears* to be the ground plane.......

If you only need to fasten the halves together, why use a threaded ground plane connection?  I think in that case a nylon bolt & nut would suffice.

I ask, what could be the *possible* relationship between the grounded threaded screw & the copper foil windings within the transformer?

take care, peace
lost_bro