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How does energy work in EST device?

Xenon02

Jul 18, 2021
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Hello!
I've a question about EST devices and similar to him devices such as AED or MM machine.
EST is a tool that is used to test if the components will be able to handle electric shock from human touch.
My question is how does this energy work exactly? I know the equation that is E = U*I*t, but when the EST is set to 25kV then does the human body will receive only Voltage from that device and the current will be decided from the Ohma law I=U/R which U = 25kV and the R - is human body. I know that device itself has a defined current but the current from the device isn't going to human body or electronic devices.

AED a device that helps human heart also has a high Voltage but the energy is higher than in EST does it mean that the impuls last longer in AED?

My main question is if the the electric arc gives to devices only Voltage and the resistance of those devices changes it into current? Or does this electroc arc also convert current from 1 device to another?

I'm very sorry for my poor english and this topic is only for my Nixie project that can reach 70 Volt and I want to know how can I understand the energy itself so I can use proper items.

Thank you for reading my topic.
 

Xenon02

Jul 18, 2021
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Good place to start, saves any long winded reply and wheel re-inventing.

https://en.wikipedia.org/wiki/Electrostatics

To be honest this site doesn't help a lot ...

I just want to know if the electric arc from ETC or even from 1 human body to another human body only converts Voltage? Because the resistance comes from the body itself but the currency come from the equation I = U/R. So how to they estimate the energy? The equation for energy is E = U*I*t. How do the people estimate the energy?

Is anything that I say is correct?
 

hevans1944

Hop - AC8NS
Jun 21, 2012
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How do the people estimate the energy?
Electrostatic discharges are almost always associated with a fixed capacitance, on which the charge separation is stored. The electrical energy stored within the capacitor is E = 1/2 CU2, where C is the capacitance in farads, U the potential difference in volts across the capacitance, and E the energy in joules stored in the capacitance.

When the capacitance is discharged by means of an arc, i.e., ionized, conductive air, the initial energy that is stored in the capacitance is used to ionize and heat the air. At the same time (within microseconds) the resistance of the discharge path decreases from a very large value (gigaohms) to a very low value (fractional ohms) as exponential multiplication of ions through impact ionization occurs along the arc path. The resulting discharge current in the arc is very large initially but quickly reduces to zero as the energy stored in the capacitance decreases, until eventually the arc is extinguished (milliseconds).

So, how much energy is delivered to the "target" of the arc discharge? Well, we know the maximum energy that is available (see equation above), but it is very difficult to accurately apportion that energy. Much of it goes into initiating and maintaining the arc, but some of it appears as ohmic or I2R heating caused by current in the target.

But WTF does any of this have to do with a Nixie tube design project? Are you planning on making your own Nixie tubes?

Is anything that I say is correct?
What is it you are saying? Hardly anyone is wrong all the time, unless their initial assumptions are incorrect. What are your assumptions?
 

Xenon02

Jul 18, 2021
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Joined
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lectrostatic discharges are almost always associated with a fixed capacitance, on which the charge separation is stored. The electrical energy stored within the capacitor is E = 1/2 CU2, where C is the capacitance in farads, U the potential difference in volts across the capacitance, and E the energy in joules stored in the capacitance.

Oh it's good to know about this equation. It's really helpful.


The resulting discharge current in the arc is very large initially but quickly reduces to zero as the energy stored in the capacitance decreases, until eventually the arc is extinguished (milliseconds).

I thought that current is more likely depend on the Voltage and the Resistance of and object.


But WTF does any of this have to do with a Nixie tube design project? Are you planning on making your own Nixie tubes?

About the Nixie tubes. I was thinking about making a simple clock, but I was wondering what would happen if the capacitor had a malfunction. And the video from Electric Boom that showed how EST works made me a bit curious.


What is it you are saying? Hardly anyone is wrong all the time, unless their initial assumptions are incorrect. What are your assumptions?


Well maybe its wrong or not. But I'm assumption that discharge current depends on the Voltage and Resistance of an object from the basic equation of Ohm's law that is I=U/R. But I am probably simplifying it.

Also thank you for telling me about the equation of capacitor energy.
 
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