Test Results of the Basic NPN LED flasher.

I like it! I think I'll try the circuit tonight and see how it works with a coin cell, a white LED, and my "1 transistor flyback converter" circuit.

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No. The reason it works is the fold-back characteristic of the LVceo breakdown of a transistor. In this case the emitter actually functions as "collector" and vice versa, giving a lower threshold.

Simulation doesn't work because the BJT model doesn't include this effect.

...Jim Thompson

I have determined that the "Mextram" model covers BVceo/LVceo effects. PSpice has this in their "Level=2" model. I don't know if LTspice has this or not. Of course good luck at finding a manufacturer that includes these parameters ;-) ...Jim Thompson