Lasersaber strikes again. A joule thief king ?

[scifi123]

  Here are the LTSpice files for those who want to run the simulations themselves.

[scifi123]

  TinselKoala, if you tell me the oscillation frequency of your real circuit I can adjust the LTSpice circuit to match it.

[d3x0r]

  Can you post the LTSPice schematics that you got to oscillate ?

I looked, but my system crashed and I lost the VHD that had spice.
I had some falstad sims that worked too...
I'll see what I can dig up

[d3x0r]

I'll see what I can dig up

I got nothin.  most simulators require more elasticity in their systems; adding 0.01ohm resistances and 10pF capacitances often helps them behave more like real world things when the thing is a boundary condition...
might be your voltage; might be your idea of top and bottom of the transformer are backward from how it should work.
The LEDs are driven by a low voltage...
might also try setting 'start DC voltage at 0'... without the 1Mohm resistor, having a capacitance beyond the primary coil from power (collector side coil), then a small current can be generated on the other side to pull the npn high, which will allow a higher current through the secondary.  This rising current causes the secondary at the load side to go high, and the base side to go low...


The circuit on http://www.overunity.com/14794/ka4ep-torch-kacher-torch/msg411220/#msg411220  adds some complexity, and the secondary ends up going to ground instead of back to the base... using just the low side of the coil on the base kacher-esque.   I didn't include simulation links there either; sorry.

[skycube]

Hi. Try this  LT simulation. It works...