Why a Co2 Laser PS has high voltage insulation only on the positive?
- Thread starter rg12
- Start date
john61ct said:
Doesn't make sense...
The tube has a huge thick insulation around the positive end and a totally flimsy thin negative pole with zero insulation.
I've seen the positive pole on youtube shooting lightning through that huge insulation while the negative never had that problem like it doesn't have the super high voltage going through it.
It usually means the negative side of the power supply is grounded or close to ground. There will be HV between the positive and negative terminals regardless, but inside the power supply, one side may be connected to ground. If you had a HV meter, you could measure this.
If you are asking for the underlying science or about that specific device being "different" that's above my pay grade.
But it is normal in "ungrounded" DC applications generally - where that term is reserved for "true Earth Ground", as opposed to Common Reference and Negative Return
all mobile use cases are ungrounded in that sense
for all the switching, circuit protection etc to be on the positive side between source and sink
while all the various circuits' (even differing voltages, say 12-48V) negative sides relatively exposed, connected to the vehicle engine bloc and chassis at multiple points
thus exposed to where fuel, children and pets can make contact etc.
This is not universal - sea water corrosion issues for example on metal hulled boats
but generally the norm.
Seen over 15kW DC generators rigged that way
But it is normal in "ungrounded" DC applications generally - where that term is reserved for "true Earth Ground", as opposed to Common Reference and Negative Return
all mobile use cases are ungrounded in that sense
for all the switching, circuit protection etc to be on the positive side between source and sink
while all the various circuits' (even differing voltages, say 12-48V) negative sides relatively exposed, connected to the vehicle engine bloc and chassis at multiple points
thus exposed to where fuel, children and pets can make contact etc.
This is not universal - sea water corrosion issues for example on metal hulled boats
but generally the norm.
Seen over 15kW DC generators rigged that way
Yes, "chassis ground" nearly always is what ensures the Common Reference point across multiple circuits.
Some devices end up with potential hot on the outside
and then carry a big warning "intended only for use within enclosed equipment"
or have to use very thorough external insulation to protect the user.
Some devices end up with potential hot on the outside
and then carry a big warning "intended only for use within enclosed equipment"
or have to use very thorough external insulation to protect the user.
john61ct said:
So if the positive arches to the chassis and I'm touching the chassis then I'm getting fried?
How dangerous 15kv is under such low currents?
Isn't it like a taser only with a much lower voltage since they both have close to zero current and just make you dance for a moment?
rg12 said:
No, the danger comes when your body (and especially going across your torso not just down one side)
is the "shortest" (lowest resistance) path **between** the positive and negative
> How dangerous 15kv is under such low currents?
> Isn't it like a taser only with a much lower voltage since they both have close to zero current and just make you dance for a moment
Complex question, lots of variables.
Plenty of deaths from getting tased, it is just "less lethal" not non-lethal.
Do some googling soon you will become a relative expert.
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