[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [TCML] difference between 10 mA from a flyback and a low voltage PSU ?



Thank you very much to all those who answered, it is always a pleasant
surprise to see that there are people who respond.


I want to do a project with a flyback or an ignition coil, but
I realize I do not quite understand the way they work.



This is roughly how I imagined things for a flyback :
 
_I saw it a bit as continuous electrostatic discharges and my main concern is :
what is the voltage and what are the values of the current and the
power which pass through the human body when an arc of 1 or 2 cm
(1 inch) touches the body ?

for example : 30 000 V ? (at the skin ?)
80 W (dissipated in the human body ?...),
and 2,6 mA ?

_What I do not understand is the fact that currents of 10 mA
are used without any problem in iontophoresis(electrotherapy)
(ramping current however,with current densities around 0.2 mA / cm ²);
and - if we exclude the effects of frequency - I thought
that even 5 mA from a flyback would be much more intense ?
is this the case ?


 _By the way, if the voltage is 30 000 V, how can there be, say 5 mA
(instead of very short impulse, high amperage current) ?
However, I understand that question is too complicated to explain quickly...

... maybe, another issue... :

<< It's WHICH path the current takes, and to what
degree the localized voltage drop is. (Ever done any study on mesh
currents, Norton and Thevenin analysis?)
The voltage drop is a function of the applied VOLTAGE to the network,
ie; the human body. Ergo, a higher source voltage at equal current is
going to result in a higher voltage drop (and power dissipation.) >>


...I don't understand quite well :  with a human body,
the output voltage of the flyback will not be 30,000 V, but much lower ?
where takes place the power dissipation : in the flyback ?...


thank you again for the detailed anwers already posted !

Alphonse


________________________________
 De : Jerry Turdjmann <jturdjmann@xxxxxxxxx>
À : "tesla@xxxxxxxxxx" <tesla@xxxxxxxxxx> 
Envoyé le : Samedi 18 août 2012 22h42
Objet : [TCML] difference between 10 mA from a flyback and a low voltage PSU ?
 
Hello,
I'm trying to learn the basics of High Voltage electrical safety, so,
a safety issue, and perhaps an ingenuous question :

what is the difference between a current output of 10 mA from a flyback
and a direct current (not pulsed) of the same intensity of 10 mA provided
by a low voltage power supply : I see what gives this one, but what
are the differences of the flyback in effects on the human body ?

If the intensity is the same, the power output of a flyback is higher than that
of a low voltage power supply ?
eg : 30 000 V . 0,01 A = 300 W (flyback power output)    beside     10 V . 0,01 A = 0,1 W
So, is there a difference in effects on the human body from this higher power
even with the same current ?

Any (detailed) explanation would be welcome !

Alphonse

_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla