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What Is Reverse Voltage?

Alexis W.
Alexis W.

Reverse voltage is a type of energy signal created when the polarity of an electrical current is reversed. Such voltage occurs often when the reversal of the polarity is applied across a diode, forcing the diode to react by functioning in reverse. This reverse of function can also create a breakdown voltage within the diode, as it often causes the breakdown of the circuit that the voltage is being applied to.

Reverse voltage occurs when the connecting source of the energy signal to the circuit is applied in an inverted manner. This means the positive lead source has been connected to the ground or negative circuit lead, and visa versa. This transferal of voltage is often not intended, as most electrical circuitry is not capable of handling the voltages.

Man with a drill
Man with a drill

When the minimum voltage is applied to either a circuit or a diode, it may simply cause the circuit or the diode to operate in reverse. This could cause a reaction such as a box fan motor spinning the wrong way. The item will continue to function in such instances.

When the amount of voltage applied to a circuit is too great an amount of signal for the circuit to receive, however, it’s referred to as a breakdown voltage. If the input signal that has been reversed surpasses the allowable voltage for the circuit to maintain, the circuit can be damaged beyond the point of remaining usable. The point at which the circuit becomes damaged is what the term breakdown voltage refers to. This breakdown voltage has a couple of other names, peak reverse voltage or reverse breakdown voltage.

Reverse voltage can cause a breakdown voltage that affects the function of other circuit components as well. Outside of the reverse voltage damaging diodes and circuit functions, it can also become a peak reverse voltage. In such cases, the circuit cannot contain the amount of incoming power from the signal that has been reversed and it may create a breakdown voltage among insulators.

This breakdown voltage that can occur across circuit components can cause the breakdown of component or wire insulators. This can turn them into signal conductors and damage the circuit by conducting the voltage to different parts of the circuit that aren’t to receive it, causing instability across the entirety of the circuit. This can cause arcs of voltage from component to component, which can also be powerful enough to ignite different components of the circuit and result in a fire.

Discussion Comments


Is it true that any given atom cannot hold more than 8 electrons in an energy level? If it is, then how does one explain the state of copper, which has 18 electrons in the second outermost energy level?


@NathanG - I think that’s because you’re dealing with a relatively small amount of voltage so it doesn’t do any damage.

The article talks about fans spinning in reverse when you reverse voltage. I don’t think your radio could work in reverse (maybe the receiver will become a transmitter?).

So the worst that happens is just that it won’t function. I think if you deal with household electricity, you may be looking at putting out some fires or blowing out some lamps, however.


I have this transistor radio that I listen to at work. I don’t have rechargeable batteries and so I find myself constantly buying new batteries since I listen to it all day and run the batteries down.

Once in a while, I do something really absentminded like putting the batteries in the wrong way and then wonder why the radio isn’t working. You’d think that seeing the springs inside the battery terminal case would give you a clue as to which way is positive or negative, but like I said, I do some absentminded things now and then.

Once I figure out what I’ve done I flip the batteries to their correct polarity and everything works fine again. However, I’ve never had it happen where the radio was destroyed in any way from reversing the polarity.

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      Man with a drill