Torroid vs. SMPS

[ChocoHolic]

Originally posted by mzzj


Not creepage issue as there is hole in pcb. Clearance values apply.
I guess that if it really is desingned as sparkgap its purpose is to have controlled point of discharche, insulation break and surface flashover are much worser choices as the will/can lead to permanent degradiation in safety whereas airgap doesnt mind at all.

Hm, so it is preferred in case of an heavy spike on the mains to protect
transformer rather than the person?

: Ironic Mode OFF:
Or is the estimation as follows:
It is not probable that somebody touches the secondary right when
such critical event takes place. But surely somebody will touch sometimes after that and then it is better to have the isolation still working. ...would make sense for me...

[mzzj]

Originally posted by ChocoHolic


Or is the estimation as follows:
It is not probable that somebody touches the secondary right when
such critical event takes place. But surely somebody will touch sometimes after that and then it is better to have the isolation still working. ...would make sense for me...

Or really powerfull ESD from user. I remember when i was kid that we were playing in winter at school, 25mm sparks were quite easy to generate on lacquered wooden floor when sliding with wool socks.
It hurted like quite badly on fingers so we kept fork or similar in hand to spread current and shock others with fork/spoon whatever

Too bad that after couple of years of fun they re-laquered that floor with some more modern stuff that was generating 5mm sparks at best.

[Kenshin]

If use a spark generator to hit something on the mains, will the spark sustain and conduct mains electricity to the generator?

It's a problem I often worry while playing with gas lighter ignitor: The spark of it is safe, but what would happen if use it to shock something on the mains?

[subwo1]

I think it depends on where in a circuit you apply the spark. If there are components with sufficient dielectric strength or voltage rating in series with the sparker in the circuit, then the mains voltage should not flash over.

[Kenshin]

Originally posted by subwo1
I think it depends on where in a circuit you apply the spark. If there are components with sufficient dielectric strength or voltage rating in series with the sparker in the circuit, then the mains voltage should not flash over.

(suppose) spark to a naked wire, the spark is in the air.

[subwo1]

The output impedance of the sparker will offer protection is the answer that comes to me now.