High Voltage Hazard

[dknguyen]

If I needed to step up a 24V battery-based system to 120V with a maximum current capacity of 500mA, does this fall into the range of hazardous yet? How high does the current have to get before it becomes dangerous? What would happen to me if something went wrong with a 120V system that can supply a maximum of 500mA?

Thanks.

 

[Papabravo]

6 mA can be fatal if it passes through you heart. Normally the human body has a fairly high resistance so it takes a large voltage to make that amount of current flow. There are circumstances that can lower the body's electrical resitance making you more vulnerable. That's why electricians always work with one hand in their pocket.

 

[Styx]

it only takes 6mA of current through the brain or the heart to kill you.
What voltage is required to drive this is dependent on person to person BUT the general British safety limit is anything below 50V is safe, above that then isolation,protection,interlocks and a bloody load of paperwork & cost start coming into play.

If you are trying to produce 120V@500mA this falls into the relm of dangerous.

As I said 6mA is the limit, But saying that a lower limit but high enough voltage at the heart will cause it to stop.

 

[HarveyH42]

6 mA can be fatal if it passes through you heart. Normally the human body has a fairly high resistance so it takes a large voltage to make that amount of current flow. There are circumstances that can lower the body's electrical resitance making you more vulnerable. That's why electricians always work with one hand in their pocket.

I thought electricians kept one hand in their pocket because of "impure" thoughts...

 

[dknguyen]

Nitinol

Hmm. Okay thanks. I was wanting to loop thin Nitinol wire back and forth over a bunch of pulleys to increase its pulling power while maintaining its fast cooldown time...but it would take 120V to pass the required current through that much resistance....

I guess I will use thicker wire and lower voltage to do the same thing...but with much slower response time.

 

[neon]

final note guys. the current is the killer not the voltage it has being tested that ~30 v you can feel it through the skin depends temp moisture and so forth. most people do not realize that a D cell can kill you only 1.25v how break the skin get to the blood rich in sodium [metal] and 2 amps can be delivered into your body the voltage will be virtual zero but the current will be 2 amps enough to kill you. 6ma 100ma is not a gauge it all depends how and to whoom. HI voltage accidents power line belive it or not the exit was the penis because of blood rich appendage sick but true.

 

[Hero999]

I don't know what you're going on about but a D cell cannot kill you, the resistance of your blood and body tissue is far too high to allow a lethal current to flow at that low voltage.

 

[blasto]

To answer your question, the max current being equal is irrelevant. The voltage determines what the current through your body will be, even though as others have suggested, you can still be in trouble at 30VDC given "ideal?" conditions.

The generally accepted danger from electrocution in the ranges you are talking about is current flowing across the thorax, inducing ventricular fibrillation. The current required to do that is depending on the person 30 - 100 mA to 200 mA. As for "across the brain...." I know of the odd ECT patient that has been through quite a few beneficial currents in the region!!!

Just as a side note, a "D" cell would practically need to have electrodes connected to each side of the heart to induce VF....