Can low power damage components?

[xvi]

So in theory why does your car provide 14 volts when its a 12V system? Voltage fluctuates while a PSU is running, you can verify this in the Bios check the 3V + 5V feeds.

Car voltage is higher to charge the battery. Many car accessories have a decently good tolerance to voltage since it is a bit necessary. 13.5v to 16v is intentional. The way I understand it, the alternator will pulse, for example, twice the voltage at 50% duty cycle to equal the correct voltage

On PSUs, voltage is commonly set intentionally high so that the voltage droop under load stays within spec. Take two identical power supplies, one set for 12v and one set for 12.2v, the former will drop out of "normal" 12v range as defined by the ATX specification slightly before the latter.

I'm simplying it, obviously resistance changes as different parts of the CPU are used, but assuming constant load (or idle,) the resistance will generally speaking remain the same. When the resistance changes is when load on the CPU changes, in that case I would say that transience would be more likely to kill a CPU, not low current. High voltages and high currents is what damages devices, not having too little.

The simple point is that low voltage + not enough current will not damage a device. It doesn't harm a transistor if the base doesn't reach its saturation point or anything. The problem is if the voltage is too high and it's over the transistor's breakdown voltage. The real thing to take away from this is that drdeathx is wrong.

Do you see cell phones failing (physically, not the battery. ) because you let the battery fully discharge? Common, this argument is really kind of ridiculous.

Voltage regulators keep the voltage constant. Like W1zzard said, logic on the battery/phone will kill the power before causing physical damage.

 

[Aquinus]

In terms of PC components, I don't think it is the actual GPU or CPU that gets damaged, but rather the VRMs. They are designed to take 12v /- 10% in and output whatever voltage the GPU/CPU needs. But if the voltage going into the VRM drops the amps go up, and the VRM has to work harder to supply the component with the power it requires. This could damage the VRM.

Not that you're wrong, but I'm pretty sure the PSU will shut off or fail before the VRMs get exposed to that kind of voltage. Considering the PSU has to draw more current to do the same job, the amount of heat that it generates go up very quicky if the PSU stays active. All in all, I'm pretty sure a brownout would damage your PSU more than any other component. Surges on the otherhand are a different story. Also, I'm pretty sure that modern powersupply need under and over voltage protection by spec.

Yup! Here it is.

1.3.1: The power supply shall contain protection circuitry such that the application of an input voltage below the minimum specified in Section 3.1, Table 1, shall not cause damage to the power supply.

Source

...and that "low voltage" limit is 90v AC on 115v mains iirc.

Here is a snippit from a superuser.com thread:

Typically power supplies have an input section composed of a bunch of interesting circuitry that, at the end of the day, provides about 308 VAC to a transformer, which then powers the regulation and conditioning circuitry. This circuitry actually forms the major basis of the regulation circuitry, and if you are using less than the full wattage of the power supply may be able to manage with significant undervoltage conditions without falling out of regulation on the output side.

When a brownout occurs, the powersupply will attempt to deliver the rated current for as long as it can (based on the incoming voltage and current) and if it cannot maintain regulation it'll deassert the Power Good signal going to the motherboard. The motherboard is responsible for deasserting the power on signal going to the supply, and if it does so in time, then the supply will drop all its output and turn off.

If the motherboard fails to do this, the powersupply should drop its rails when it falls too far out of regulation, but that is not guaranteed, and with low quality power supplies you may find your components and motherboard receiving undervoltage conditions as well.

What happens at that point depends on how robust those components are, but it's generally not a good thing as the components attempt to operate at the lower voltage. Keep in mind that the power supply always supplies an undervoltage on power down for a brief time (dropping the outputs to 0 is not instantaneous) so very brief undervoltage periods are fine. The problem only occurs if the power supply remains in an undervoltage state for a long period of time, which can only occur if both the power supply and motherboard fail to realize the problem, and continue to attempt to operate.

Source

 

[newtekie1]

Not that you're wrong, but I'm pretty sure the PSU will shut off or fail before the VRMs get exposed to that kind of voltage. Considering the PSU has to draw more current to do the same job, the amount of heat that it generates go up very quicky if the PSU stays active. All in all, I'm pretty sure a brownout would damage your PSU more than any other component. Surges on the otherhand are a different story. Also, I'm pretty sure that modern powersupply need under and over voltage protection by spec.

First, not every PSU adhears to ATXSpec. Those cheap PSUs that weight less than a feather, I guarantee you they aren't following ATX Spec and probably don't have any protection in place for a brownout.

Second, I'm not saying a brownout kills components, they usually kill the PSU, I've seen it, but rarely anything else. I was just using the brownout as proof that low voltage can in fact kill electronics.

The PWM on the motherboard or graphics card also doesn't have the protection features built in that a PSU does. So they are even more vulnerable to low voltage situations. So when a PSU is overloaded to the point that the 12v voltage is below 11v, it could definitely damage something.

 

[LAN_deRf_HA]

This is the wrong way to go about this conversation. You need to find if there's confirmed cases of this or not first. If there aren't you can theorize why, and if there are you do the same until the explanation fits the result. Everything so far is "blind" theorizing which isn't all that productive.

 

[TheoneandonlyMrK]

Imho if a psu is strained to the point of drooping a lot and under volting its main rails its technically possible for damage to occur .
Its unlikely but certainly possible.
Not in my op directly the low voltage though , more the circuit instabilty due to the complex power regulation components overworking or being forced outside there designed operating specs, in the extreme causing power spikes beyond the specs of parts later in the circuit and causing drdeath of the mobo and possibly more.
Oh and im baseing this off having seen it a few times Rip Q6600 oh again, Before you say it its not prove able easy as dead bits stay dead mpre oft then not and I was using a corsair psu not a cheapo