Joule Thief 101

[tinman]

Brad:



In post #1202 PW is mistakenly referencing a different subject.



MileHigh

Did anybody say that they completely cancel each other out?  Presumably you have a large current in L1 and a comparatively smaller current in L2, for both a high and low base resistance.  That means that the current flowing in L2 takes a slice out of the magnetic energy built up by the current flowing in L1, but does not completely cancel it out by any means.

that small slice being taken from L1 by L2 is where you are lost MH,as the small slice that is taken from L1 by L2 is given right back by L2 due to the current flowing through it. The two fields built by both coils are apposing field's-not like fields,as the current is traveling around each coil in the opposite direction,and this causes a bucking field between the two.

Does current flow in L2 reduce the magnitude of the magnetic energy stored in the toroid that was built up by the current flow in L1?  The answer to that is yes, and TK and PW also stated that.  Go find the references yourself.

Please back up your claim,and post these two statements by PW and TK.
The answer is that the higher current flow through L2 ,produces a stronger magnetic field in the core--that is my claim,and im sticking to it. I have proven this to be the case,and i am yet to see PW or TK refute this claim.
Please post the post number where PW and TK say this.

Brad.

[picowatt]

In post #1202 PW is mistakenly referencing a different subject.

I thought you two were "discussing" whether or not decreasing the base resistance increased the collector (and L1) current or just produced additional waste heat in the base resistor.  Perhaps I misunderstood.  As I said, I have no dog in this hunt.

This would of course depend on whether Q1 is fully saturated at both the lower and higher base resistance. 

Measuring Vce and Ic at the two base resistances should help clarify is Q1 is fully saturated (turned on) at both base resistance values or is turned on harder with one more than the other.

PW

[MileHigh]

Please post the post number where PW and TK say this.

This is your bad karma biting your ass.  Find the information yourself.

[picowatt]

... That said, I do not believe the base current flowing thru L2 is acting in the manner you surmise.  In fact, I would think that current flowing thru the base (and L2) would generate a flux in opposition to that generated by current flowing thru L1...

[tinman]

Brad:

Did anybody say that they completely cancel each other out?  Presumably you have a large current in L1 and a comparatively smaller current in L2, for both a high and low base resistance.  That means that the current flowing in L2 takes a slice out of the magnetic energy built up by the current flowing in L1, but does not completely cancel it out by any means.

Even better, look at a toroid and the winding directions and the direction of the current flow for the two coils that make up the Joule Thief transformer and figure it out for YOURSELF.  Don't just blindly assume that you are right.  Blind assumption gives you a 50-50 chance of being right and you are wrong.



Does current flow in L2 reduce the magnitude of the magnetic energy stored in the toroid that was built up by the current flow in L1?  The answer to that is yes, and TK and PW also stated that.  Go find the references yourself.

MileHigh

In post #1202 PW is mistakenly referencing a different subject.

Bullshit MH--your full of shit.
PW is talking about the very same subject,and now you are trying to place him in your court,when he is here to help. You are going to drag him down with you,and the outcome will be he leaves because of your lying ways.

Quote PW- Because I never said you were wrong.  I only stated that up until then you did not actually measure the increase in base current but were making assumptions based on proxies.

Solid proof MH that he was refetring to the correct subject,as those proxies where the rise in light output from the LED due to a stronger magnetic field being built,which is a result of a higher current flow through  L2 by the reduction of base resistance.

Quote:

You have the wrong issue, it's about your claim that current flowing through L2 increases the magnetic energy in the core and hence the brightness of the LED.

Please tell us all how you can increase the magnetic field strength in the core, without increasing the current flow through L2--this should be good.

Brad