>  Peter, I'm not very sure you have right here. The circuit does not work
> at resonance this is sure. A series resonance (R-plasma, L-transformer
> coil, C-series capacitor) which is current resonance will not help at
> all. If would be a parallel resonance then yes, I would be agree. But is
> not. The capacitors values are usualy 2x33pF/2KV. There are also usually
> two bipolars as you say and one NMOS. I have doubts the DC created by
> tube rectifying will bother the circuit.

I did not write anything about resonance, or about current limiting. I
only said they prevent dc through the *lamp* mostly, but also through the
transformer. The transformer will only be affected in a self-oscillating
circuit, and only when dimming the lamp (the lamp will flicker and the osc
can change modes or 'sing'). In a driven converter there is current
feedback and the chip will not allow the transformer to be saturated.

If you want to see what the lamp does, rectifier wise, put a 10mA
d'Arsonval (!!!) dc miliammeter in parallel with the capacitor, turn on
the circuit and then dim the lamp and see what happens. The effect is much
stronger with old lamps. Note that the behavior depends a lot on the kind
of lamp used. A FL lamp run with dc can fail after 100 hours or less.

Peter

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