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Does Voltage Or Current Kill Electronics? Answered

I've heard it a million times "It's the amps that kill".  But what if we are talking about electronics?  Would something that is 1.5 volts at an amp affect an electronic device? What if I had something at 10 kV, but virtually no current, like a piezoelectric ignitor?  (Maybe both of these examples would, I'm not sure,  but which is more likely?)

Just wondering if someone can tell me whether it is mainly the volts or amps that fry electronics. And also how this happens. Does the high voltage short circuit things? Or is it the current that would overheat the small little circuits inside?

I'm thinking that both are possible, but I'd like to know which is more likely to kill electronics, voltage or amperage?



Best Answer 6 years ago

As Randy said, both conditions can destroy electronics, depending on the specific components involved.

Excessive voltage will cause breakdown and arcing, either between separate exposed contacts (especially little points of solder), or through an insulating or dielectric barrier (for example, the dielectric in a capacitor).

Excessive current is generally caused by excessive voltage. Passive components have a specific, fixed resistance; the current through them is determined by Ohm's law, I = V/R. Excess current can cause overheating and burn-through of components, leading to open circuits.

Once you get into active components (piezoelectrics, op-amps, transistors), then the effects of going outside the components' specifications can be more complex, but never good.

It's the electricity going through them (current), the voltage driving it is irrelevant so long as there's too much.
However, if you have too much current going through something because the insulation/material  failed above it's design voltage, you may say that's "too much voltage".



Is it the height you drop something from, or the speed at which it hits the ground, which breaks it? Technically the latter, but the former is what causes the latter.

reading all the responses to this, yours was literally the best way it was explained, you made it easy to understand.

(And the speed can be achieved from a lower height if driven by something more than gravity, or if falling with less air/water/whatever resistance.)


6 years ago

Voltage is impressive can be visible but it is current that does the damage.
Here is how, using a guinea pig semiconductor PN junction.
A normal diode that is rated at 100 peak inverse voltage withstanding ability.
Then raise the voltage above 110 slowly
  1. A micro current flows over the outside PN surface NO Damage Yet,  if the voltage is reduced the diode is still good to use.
  2. A little more voltage & very quickly milliampDamaging current flows.
  3. As the current flows and begins heating the surface eroding material
  4. High current flowing long enough for silicone melting sputtering heat to develop maybe several hundred microseconds depending on size of the junction and a full plasmic blow-out.
The damage is done by  Current Flow.
The heat can melt the metal Leeds to become a Shorted diode or
blow out any connection to become an Open diode...................................   A


SInce we generally work with constant voltage sources, its probably simplest to say excess voltage kills electronics, by causing excess current to flow or in extreme overvoltages to cause "flashover", where an arc causes a channel to be formed that allows more current to flow, and often a fire to start.

There is also the difference between the voltage the device will run at, and the amount of static discharge voltage that it will withstand.

In some cases, it is the combination of voltage and current, which combine to make the power dissipated, which heats up the component, damaging it.

They both can potentially destroy electronics. Many parts tend to be rated for both maximum voltage and maximum current.