15kV AC on a standard 5mm LED

[MasterTenku]

well, what do 5 VIRGINS and a couple dozen beers...

[samiam2013]

the led was only okay because even though it was 450 amps, the led, being a resistor, and an exponential one based on current, actually would have been able to save itself.

[cheetawolf]

the reason it doesnt blow is that the ARCS ARE GIANT RESISTORS!

Lol

[dav1dh0ff]

nice!

[neelradhakrishnan]

When I put an LED against my phone battery, it turned on, got really hot then blew up and made half the bus smell.

[EatOoze]

That LED was probably screaming in agony.

[madamerotten]

LED torture is morally wrong. You killed a wonderful LED that probably has a family, and would have lived hundreds of years in a proper, loving environment. Shame on you.

[sirsilentbob]

Lol!

[uorriz]

yeah but, that's something wrong in your data: 15000 V * 0,03 A = 450 VA !!!

A standard 5mm LED can't lead that power!

I agree what other comments say: you shold consider the high impedance of the secondary of the transformer; 15 kV is the voltage you can measure without any load.

[Chris77S10]

If the current is limited to 0,03 A, the controller will reduce the voltage, perhaps on 2 V :-) That´s the reason, why the LED survives

[grogyan]

The neon transformer is current limited to 30mA.

All the current is passing through the LED, haf in the forward bias, and the other half in the reverse bias direction.

Only one bias produces light and if it were DC, you would at most get 30mA, thats why the LED doesn't blow up.

[Automatic74]

have you considered the power was supplied by a simple high voltage low current transformer, rectifyed to dc giving a static electricity effect with minimal current flow. Remember the current is restricted to the power rating of the TF regardless of voltage

[mrfanman2u]

Most Definetely! From one elctricity geek to another, LoL

[grogyan]

But the mere fact that the LED still worked afterwards is what was really impressive.

There would be some loss across the terminals, but I just don't know.

Cool none the less.

[arielco]

There was never 15kV across the LED, or it would have stopped being a LED at all in half a msec.

Have you considered the (high) output impedance of your supply? 15 kV is the zero-load voltage, but it drops as soon as you draw current. And the loose wires allow quite a bit of drop too. Most likely it was around the 2.5 v / 40 mA the LED can take without burning.

Try applying a 12v battery - you'll see one green flash that turns bright red, and soon enough it'll be black forever.

[mrfanman2u]

The slight glow of your led led me to believe it was connected backwards, and the 15kv was overcoming the "check valve" property of the diode itself.  I am subject to be wrong though.

[mrfanman2u]

Very true. I believe you are losing a lot of your potential with your spark gap as well. Granted i figured you did that as a safety precaution. I am very sure you had at least a portion of the voltage going over the surface of the led.

But, I had meant in my earlier post. If the led were connected in correctly in a normal situation (design voltage) the led would do nothing, no glow no nothing.

[grogyan]

We were unsure whether the AC was going over or through the LED, byt considering the properties of an LED leads us to believe that the AC was going through it, because if it were rectified it would be about 30mA and seeing as an LED works as a diode, in half wave rectification, presto LIGHT!

If it were 15kV DC @ 30mA, the LED would sure to blow.

[mrfanman2u]

just curious, but.

have you considered you may have had the led "connected"(used very loosly, lol) backwards, and the 15kv actually was overcoming the diode's properties of only letting voltage/current flow in one direction, and causing it to slightly glow like that?

You may have thought of this when making the vid, but had to point it out!

[enginuitor]

The supply is AC -- there's no such thing as "backwards" in this case...