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New machine - fan making noise

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  • RidelynnRidelynn Member EpicPosts: 7,146

    Actually it only takes 0.1A to be fatal. You don't need a lot of volts to drive 0.1A - it all depends on where you make contact with, what your grounded against, and your physical body chemistry (which varies based on a huge number of factors). You could conceivably get a fatal shock with a voltage as low as 30V.

    https://engineering.dartmouth.edu/safety/electrical/TheFatalCurrent.html

    Down to around 1mA can be felt. Inside a switching power supply, even though the output voltages are only 3.3/5/12V, the internal voltages on the capacitors can actually well exceed even the AC line voltage, depending on the circuitry used inside the PSU.

    Capacitors can hold a charge for a very, very long time. If it's open circuited, a good cap can hold a charge for days/weeks/even longer. Don't think just because it's been unplugged for 12+ hours that it's safe. Don't think that just because you held the power button with it unplugged that your safe. There are methods that electricians use to verify and discharge capacitors, I wouldn't do any of them if you haven't been trained on it or have the proper tools - because it's your life at stake.

    We have a 120VAC-12VDC industrial power supply in our shop - I should take a picture. It's a 20A supply - so not too dissimilar from a computer power supply really, aside from it being about 1/3 the size and built to mount inside of a industrial panel rather than a computer case. One of the guys tried to fix a broken terminal on it. The screwdriver welded to the chassis because the capacitors were still charged and he accidentally shorted across them. Fortunately it was the screwdriver and not him. We keep it in the warehouse now as a reminder of electrical safety.

    Don't open up your PSU, it's not a good idea. If the fan goes out in your PSU - either it's still under warranty and you get a new one that way, or it's old enough that it's time to get a new one in the first place and you buy a new one. (Or you get ghetto and your zip tie one to the outside of the PSU fan grill, but you don't open up the PSU)

    I'm glad the OP found his problem and it wasn't PSU-related, but there was some really bad advice given on going into the PSU, and this is just a PSA (with lots of TLAs) in case someone hits on this thread later on.

  • Kevyne-ShandrisKevyne-Shandris Member UncommonPosts: 2,077
    Originally posted by Ridelynn

    Actually it only takes 0.1A to be fatal. You don't need a lot of volts to drive 0.1A - it all depends on where you make contact with, what your grounded against, and your physical body chemistry (which varies based on a huge number of factors). You could conceivably get a fatal shock with a voltage as low as 30V.

    https://engineering.dartmouth.edu/safety/electrical/TheFatalCurrent.html

    [Why did I expect this?]

     

    Volts isn't what kills you. A lightning victim could get hit by 50,000 volts and live. It's the amps...and 1amp kills a person regardless.

     

    1 cap in a power supply capable of storing 1 amp of energy = fatal.

     

    That's all the math you need to know about it.

  • syntax42syntax42 Member UncommonPosts: 1,378
    Originally posted by Kevyne-Shandris
    Originally posted by Ridelynn

    Actually it only takes 0.1A to be fatal. You don't need a lot of volts to drive 0.1A - it all depends on where you make contact with, what your grounded against, and your physical body chemistry (which varies based on a huge number of factors). You could conceivably get a fatal shock with a voltage as low as 30V.

    https://engineering.dartmouth.edu/safety/electrical/TheFatalCurrent.html

    [Why did I expect this?]

     

    Volts isn't what kills you. A lightning victim could get hit by 50,000 volts and live. It's the amps...and 1amp kills a person regardless.

     

    1 cap in a power supply capable of storing 1 amp of energy = fatal.

     

    That's all the math you need to know about it.

    You can't store amps, because amps are a measure of numbers of electrons passing by a point.  Storing amps would be equivalent to saying you can store a flow (measured in gallons per second) of a liquid.  You can store the liquid, but the flow is a measurement of rate.

    Capacitors are measured in Farads, which is a potential difference of electrons when charged by coulombs (actual amount of electrons).  Capacitors are also rated for a certain maximum voltage potential and the stored electrons' voltage can be measured.  

    It would be inaccurate to say amperage kills you.  This is because voltage is required to drive the amperage.  If you don't have the voltage potential, you will never reach an amperage needed to cause harm to a person.  In addition, the devices we use to store or generate power are rated in volts and often watts as well.  This means they can deliver a maximum amount of amps at a certain voltage.

    Can a 1000V, 1F capacitor kill you?  Maybe, if it has enough coulombs stored up, and it finds an electrical path through your heart to reach a ground, and the path has a low enough resistance that the amperage through your body can reach 100mA.  

  • GruntyGrunty Member EpicPosts: 8,657
    As I said 15 posts ago. Opening a power supply is dangerous. Don't do it.
    "I used to think the worst thing in life was to be all alone.  It's not.  The worst thing in life is to end up with people who make you feel all alone."  Robin Williams
  • RidelynnRidelynn Member EpicPosts: 7,146

    It's called Ohm's Law - you can't have current without volts, and vice versa.

    They are linked.

    Your right, voltage isn't what kills, and people have survived lightning strikes of thousands of volts - but you need volts to push amps through your internal resistance. Deaths from household 120V shocks are the second leading cause of electrocution fatalities in the US.

  • Kevyne-ShandrisKevyne-Shandris Member UncommonPosts: 2,077
    Originally posted by Ridelynn

    It's called Ohm's Law - you can't have current without volts, and vice versa.

    They are linked.

    Your right, voltage isn't what kills, and people have survived lightning strikes of thousands of volts - but you need volts to push amps through your internal resistance. Deaths from household 120V shocks are the second leading cause of electrocution fatalities in the US.

    (And folks now understand what I mean by Occam's Razor died on the internet!).

     

    Amps are stored where?

     

    How long are they stored?

     

    Lightning doesn't store amps...............

  • syntax42syntax42 Member UncommonPosts: 1,378
    Originally posted by Kevyne-Shandris

    (And folks now understand what I mean by Occam's Razor died on the internet!).

     

    Amps are stored where?

     

    How long are they stored?

     

    Lightning doesn't store amps...............

    Are you still thinking you can store amps?

    The best analogy to explain electricity is with a fluid.  I'll use air as an example.  

    A difference in air pressure (voltage) make air move through a tube.  If you make the tube smaller, you are increasing the resistance, and decreasing the flow (amperage).  You can't store the flow of air, but you can store the air (electrons) and you can increase the pressure (voltage) of stored air.  

    A lightning strike could have a lot of voltage potential and a lot of amperage, but the duration is so short that the chance of death is significantly decreased.  It is just like being shocked by static electricity, which can be as high as 25,000 volts.  The current is so short-lived that it doesn't affect a person beyond a brief moment of pain, at worst.

     

    Opening a power supply is dangerous.  It isn't likely to kill you, but don't take that chance unless you have formal training on how to be safe around high voltage components.

  • RidelynnRidelynn Member EpicPosts: 7,146


    Originally posted by Kevyne-Shandris
    Originally posted by Ridelynn It's called Ohm's Law - you can't have current without volts, and vice versa. They are linked. Your right, voltage isn't what kills, and people have survived lightning strikes of thousands of volts - but you need volts to push amps through your internal resistance. Deaths from household 120V shocks are the second leading cause of electrocution fatalities in the US.
    (And folks now understand what I mean by Occam's Razor died on the internet!).

     

    Amps are stored where?

     

    How long are they stored?

     

    Lightning doesn't store amps...............


    I think we've completed the derail and turned this thread into a basic electrical lesson. Syntax addressed your amps/capacitor misconception perfectly and accurately. I think I've reached my limit of free lessons (either giving or receiving, depending on who you think is correct).

  • Kevyne-ShandrisKevyne-Shandris Member UncommonPosts: 2,077
    Originally posted by Ridelynn

     


    Originally posted by Kevyne-Shandris

    Originally posted by Ridelynn It's called Ohm's Law - you can't have current without volts, and vice versa. They are linked. Your right, voltage isn't what kills, and people have survived lightning strikes of thousands of volts - but you need volts to push amps through your internal resistance. Deaths from household 120V shocks are the second leading cause of electrocution fatalities in the US.
    (And folks now understand what I mean by Occam's Razor died on the internet!).

     

     

    Amps are stored where?

     

    How long are they stored?

     

    Lightning doesn't store amps...............


     

    I think we've completed the derail and turned this thread into a basic electrical lesson. Syntax addressed your amps/capacitor misconception perfectly and accurately. I think I've reached my limit of free lessons (either giving or receiving, depending on who you think is correct).

    http://www.mmorpg.com/discussion2.cfm/post/6195464#6195464

  • TheLizardbonesTheLizardbones Member CommonPosts: 10,910
    Originally posted by syntax42
    Originally posted by Kevyne-Shandris

    (And folks now understand what I mean by Occam's Razor died on the internet!).

     

    Amps are stored where?

     

    How long are they stored?

     

    Lightning doesn't store amps...............

    Are you still thinking you can store amps?

    The best analogy to explain electricity is with a fluid.  I'll use air as an example.  

    A difference in air pressure (voltage) make air move through a tube.  If you make the tube smaller, you are increasing the resistance, and decreasing the flow (amperage).  You can't store the flow of air, but you can store the air (electrons) and you can increase the pressure (voltage) of stored air.  

    A lightning strike could have a lot of voltage potential and a lot of amperage, but the duration is so short that the chance of death is significantly decreased.  It is just like being shocked by static electricity, which can be as high as 25,000 volts.  The current is so short-lived that it doesn't affect a person beyond a brief moment of pain, at worst.

     

    Opening a power supply is dangerous.  It isn't likely to kill you, but don't take that chance unless you have formal training on how to be safe around high voltage components.

     

    One of the ways to discuss caps is in "amp-seconds".  As in, a 1 farad cap will hold 1 amp-second's worth of electrons at 1 volt.  So amps don't measure storage, but when expressing how much power you can get out of a cap, "amps" can be part of the conversation.  Then there's the whole "amps kill you, not whatever else people are talking about" discussion.  Well, a AA battery can produce 2.8 amps an hour at 1.5 volts, which won't kill you.  You have to deliver those electrons much faster, say 2.8 amps in a tenth of a second or something similar by dumping them into a capacitor (stun guns for the win there).  It's not surprising that people can get confused by this stuff, especially if they've never so much as installed a stereo, much less messed around with the innards of a 12 volt power supply.

     

    Sometimes people give really good advice on these forums*, and sometimes people are just throwing out information to demonstrate to the forum population how extensive they think their knowledge is.  For instance, if you are trying to give a detailed explanation on capacitors to an audience that is not familiar with any of the basics, you are just trying to advertise your knowledge, not explain something useful.

     

    The useful information was finding the location of the noise, and opening power supplies is potentially very dangerous.

     

    * Really.  You will someday be amazed at the cumulative practical knowledge of the people here.

     

    I can not remember winning or losing a single debate on the internet.

  • Azaron_NightbladeAzaron_Nightblade Member EpicPosts: 4,829
    Originally posted by Fermian
    Originally posted by emperorwings

     

    I have to tilt it at 45 degreese for the noise to stop which isn't ideal.

    Probably a cable which touches the fan.

    That would be my first thought too.

    Pesky sneaky cables.

    My SWTOR referral link for those wanting to give the game a try. (Newbies get a welcome package while returning players get a few account upgrades to help with their preferred status.)

    https://www.ashesofcreation.com/ref/Callaron/

  • CleffyCleffy Member RarePosts: 6,302

    If you decide to ever replace a case fan, I recommend this one. I bought 2 of these about 8 years ago and one of them finally died after a long time in service.

    Delta Electronics 120mm

    An added feature of this fan is that if you are playing a flight simulator and flying a prop driven plane, the sound will seem so authentic your neighbors might complain.

  • GruntyGrunty Member EpicPosts: 8,657
    Originally posted by Cleffy

    If you decide to ever replace a case fan, I recommend this one. I bought 2 of these about 8 years ago and one of them finally died after a long time in service.

    Delta Electronics 120mm

    An added feature of this fan is that if you are playing a flight simulator and flying a prop driven plane, the sound will seem so authentic your neighbors might complain.

     

    And if you've got the big bucks...

     

    "I used to think the worst thing in life was to be all alone.  It's not.  The worst thing in life is to end up with people who make you feel all alone."  Robin Williams
  • CleffyCleffy Member RarePosts: 6,302
    lol since when is posting a link to newegg not allowed?
  • I wouldn't run it anymore until you measure the axises of the fan and whatever else is in the computer, if something melted, like the motherboard, heatsink or fan or graphics card, whether it be by an electrical default or it got too hot, if it gets worse the computer won't work, it can still work when it's a little melted but as soon as a circuit touches another circuit it will probably die.

    Why other posters haven't told you that and trolled i don't know, they think helping someone is a max populated server on World of Warcraft or something, there will always be new friends to make, so they can tick the others off

  • syntax42syntax42 Member UncommonPosts: 1,378
    Originally posted by lizardbones

     

    One of the ways to discuss caps is in "amp-seconds".  As in, a 1 farad cap will hold 1 amp-second's worth of electrons at 1 volt.  So amps don't measure storage, but when expressing how much power you can get out of a cap, "amps" can be part of the conversation.  Then there's the whole "amps kill you, not whatever else people are talking about" discussion.  Well, a AA battery can produce 2.8 amps an hour at 1.5 volts, which won't kill you.  You have to deliver those electrons much faster, say 2.8 amps in a tenth of a second or something similar by dumping them into a capacitor (stun guns for the win there).  It's not surprising that people can get confused by this stuff, especially if they've never so much as installed a stereo, much less messed around with the innards of a 12 volt power supply.

     

    Sometimes people give really good advice on these forums*, and sometimes people are just throwing out information to demonstrate to the forum population how extensive they think their knowledge is.  For instance, if you are trying to give a detailed explanation on capacitors to an audience that is not familiar with any of the basics, you are just trying to advertise your knowledge, not explain something useful.

    Amp-second = coulomb.

     

    Allowing misinformation to spread is bad.

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