Joule Thief behavior question.

[xee2]

Something isn't making sense.  You show the collector current of 1.5 amps so if I put two of those in parallel you said that would be cut in half so that would make it 750ma which i not good.

I said each one you add reduces the equivalent collector-emitter resistance (thus more current for a specific Vce). Each additional transistor is another current path and thus each time you add a parallel transistor you increase the current going into the junction of the collectors of all the transistors. The higher the collector current is, the higher the current in the coil will be, and the larger the voltage spike will be when the transistors turn off.

[Legalizeshemp420]

Ahhh, yes, to use Ohms Law and since it is less resistance more electrons will flow.

Now I understand I think.  So, in your 1.5Adc ifI had two of those in parallel it would be as if I had 1 transistor with 3.0Adc which makes sense as the current capacity would double but is that really what I am after when my light becomes brighter the more I add?

Thank you.

[xee2]

Ahhh, yes, to use Ohms Law and since it is less resistance more electrons will flow.

Now I understand I think.  So, in your 1.5Adc ifI had two of those in parallel it would be as if I had 1 transistor with 3.0Adc which makes sense as the current capacity would double but is that really what I am after when my light becomes brighter the more I add?

Thank you.

The higher the collector current is, the higher the current in the coil will be, and the larger the voltage spike will be when the transistors turn off. Bigger voltage spike = brighter LEDs.

[Legalizeshemp420]

The higher the collector current is, the higher the current in the coil will be, and the larger the voltage spike will be when the transistors turn off. Bigger voltage spike = brighter LEDs.

That makes sense, of course, but I read that as 1.5A dc max before POOF not that is what is making it go brighter as opposed to simply allowing it to go brighter.

Take for instance 13003 vs BC337-25.  Collector current is 1A for the 13003 and 800ma for the BC337-25 YET the 13003 is dimmer than the BC337-25 so there is more to it than just this.

[xee2]

That makes sense, of course, but I read that as 1.5A dc max before POOF not that is what is making it go brighter as opposed to simply allowing it to go brighter.

Take for instance 13003 vs BC337-25.  Collector current is 1A for the 13003 and 800ma for the BC337-25 YET the 13003 is dimmer than the BC337-25 so there is more to it than just this.

Ic max is the maximum current the transistor will take before burning up. Just having a transistor with a large Ic max does not mean you are going to magically get that current when you use it. Yes, there is a lot more to it. I think you need to review how transistors work. The collector current is dependent on many variables. Primarily Ic equals base current times the transistors gain. Thus you can change Ic by increasing and decreasing the base current.