5 ms·

Wouldn't it be safer to open the case and connect some kind of battery + adapter after the power supply?

walrus01 6y ago
Splicing into the many wires that is an atx+12v power connector, between the output of the power supply and the motherboard is way more fiddly than just dealing with the hot and neutral on an ordinary $5 PC power cord. You could also never be certain what weird ziptie and cable management system (or lack thereof) might exist in a home built x86 PC case, or if there's any room for hands to work at all... I think the thing I saw is also meant to deal equally well with a commodity x86 PC built from parts, or an Intel NUC size thing, or a corporate desktop machine with proprietary internal wiring like a slimline Dell, Lenovo, HP, etc.
ajross 6y ago
Safer for the operator? Sure. But certainly not for the device, if you're trying to keep it operating. An ATX power supply has 24 pins at 5 different voltage levels (plus any auxilliary power connectors for the GPU and drives, etc...), and motherboards are a lot less tolerant of spikes and transients than the PS on the other side. Dealing with AC power isn't really that dangerous if you're careful.
- TheSpiceIsLife 6y ago
  Even high voltage and high amperage AC isn’t dangerous. So long as you’re not earthed https://imgur.com/gallery/B2c5FfD https://imgur.com/gallery/B2c5FfD
  - dhosek 6y ago
    We had an electrician of questionable licensing do some minor work for us (replacing some switches and outlets). I asked him to tell me when I should go down to the circuit breaker to turn off the electricity and he told me not to bother. He did all the work with hot current running through the wires. I stayed close enough to be able to tell if I needed to call 911 but no closer while he worked.
    - mschuster91 6y ago
      In Germany this is called "Arbeiten unter Spannung" and perfectly legal if qualified (https://de.wikipedia.org/wiki/Arbeiten_unter_Spannung https://de.wikipedia.org/wiki/Arbeiten_unter_Spannung).
      - dhosek 6y ago
        The electrician was Croatian and, I presume, learned his trade there. It still terrified me.
    - 0xffff2 6y ago
      I've done a ton of electrical work for my own benefit over the years and I'm perfectly comfortable doing things like swapping switches with live wires. I've never once had a problem. The one and only time I've fucked up was when I cut a run of romex cable that I thought had been turned off. Lesson learned: electrical wiring is like a gun. Always treat it like it's on, and if you have to do something would be unsafe if the wiring is energized, make damn sure it's de-energized before proceeding. When you're working in that mindset already anyway, flipping the breaker for something as simple as swapping a switch/outlet hardly has any benefit.
      - allannienhuis 6y ago
        I apprenticed with my Dad. The first two rules he taught me have stuck with my my whole life: 1) Treat every wire as if it was hot. Even if you know it's not. 2) A good electrical connection must first have a good physical connection. Not sure why that second rule sticks with me :) but there has been more than one occasion when I'm fairly sure the first rule has saved me from a bad shock. And you're right - treating the wires as if hot means you can actually work with hot wires for a lot of simple things. I still turn off the breaker though :)
        nucleardog 6y ago
        The second rule is a great one that so many people doing their own work miss. The wire nut is only there to stop the wires loosening over time and provide some basic insulation. It is not there to actually attach the wires. When you twist your wires together, they should be attached well enough on their own that you'd be comfortable throwing a piece of electrical tape over them to stop them shorting to the box and leaving it as-is (but don't do that). If the only thing keeping them together is the wire nut and you being very gentle when you manipulate them back into the box, they're not actually connected. The poor physical connection creates a poor electrical connection. A poor electrical connection has resistance which creates heat. Heat creates fires. Even better after a few years when enough traffic has driven past your house and enough people have moved around inside of it and the wires have wiggled to just barely in contact so occasionally when someone walks down the hallway the lights will all flicker as the wires create some pretty electrical arc light shows, adding carbon buildup to the wires and further increasing the resistance and heat concentrated in the one tiny point of the copper where they're still sometimes connected. No reason at all for this rant. Definitely not a real example at all. Definitely didn't waste an afternoon with a toner, a drill with a pilot bit, and a borescope to hunt down the six octagon boxes someone had sealed into the basement ceiling hiding away some of the shoddiest wiring I'd ever seen. Nope.
regularfry 6y ago
Cases can have "case open" switches that tell the machine to switch off. You can't necessarily tell beforehand.
jrootabega 6y ago
Case intrusion alarms (built in or Homebrew)

Splicing into the many wires that is an atx+12v power connector, between the output of the power supply and the motherboard is way more fiddly than just dealing with the hot and neutral on an ordinary $5 PC power cord. You could also never be certain what weird ziptie and cable management system (or lack thereof) might exist in a home built x86 PC case, or if there's any room for hands to work at all... I think the thing I saw is also meant to deal equally well with a commodity x86 PC built from parts, or an Intel NUC size thing, or a corporate desktop machine with proprietary internal wiring like a slimline Dell, Lenovo, HP, etc.

ajross 6y ago

Safer for the operator? Sure. But certainly not for the device, if you're trying to keep it operating. An ATX power supply has 24 pins at 5 different voltage levels (plus any auxilliary power connectors for the GPU and drives, etc...), and motherboards are a lot less tolerant of spikes and transients than the PS on the other side. Dealing with AC power isn't really that dangerous if you're careful.

TheSpiceIsLife 6y ago
Even high voltage and high amperage AC isn’t dangerous. So long as you’re not earthed https://imgur.com/gallery/B2c5FfD https://imgur.com/gallery/B2c5FfD
- dhosek 6y ago
  We had an electrician of questionable licensing do some minor work for us (replacing some switches and outlets). I asked him to tell me when I should go down to the circuit breaker to turn off the electricity and he told me not to bother. He did all the work with hot current running through the wires. I stayed close enough to be able to tell if I needed to call 911 but no closer while he worked.
  - mschuster91 6y ago
    In Germany this is called "Arbeiten unter Spannung" and perfectly legal if qualified (https://de.wikipedia.org/wiki/Arbeiten_unter_Spannung https://de.wikipedia.org/wiki/Arbeiten_unter_Spannung).
    - dhosek 6y ago
      The electrician was Croatian and, I presume, learned his trade there. It still terrified me.
  - 0xffff2 6y ago
    I've done a ton of electrical work for my own benefit over the years and I'm perfectly comfortable doing things like swapping switches with live wires. I've never once had a problem. The one and only time I've fucked up was when I cut a run of romex cable that I thought had been turned off. Lesson learned: electrical wiring is like a gun. Always treat it like it's on, and if you have to do something would be unsafe if the wiring is energized, make damn sure it's de-energized before proceeding. When you're working in that mindset already anyway, flipping the breaker for something as simple as swapping a switch/outlet hardly has any benefit.
    - allannienhuis 6y ago
      I apprenticed with my Dad. The first two rules he taught me have stuck with my my whole life: 1) Treat every wire as if it was hot. Even if you know it's not. 2) A good electrical connection must first have a good physical connection. Not sure why that second rule sticks with me :) but there has been more than one occasion when I'm fairly sure the first rule has saved me from a bad shock. And you're right - treating the wires as if hot means you can actually work with hot wires for a lot of simple things. I still turn off the breaker though :)
      - nucleardog 6y ago
        The second rule is a great one that so many people doing their own work miss. The wire nut is only there to stop the wires loosening over time and provide some basic insulation. It is not there to actually attach the wires. When you twist your wires together, they should be attached well enough on their own that you'd be comfortable throwing a piece of electrical tape over them to stop them shorting to the box and leaving it as-is (but don't do that). If the only thing keeping them together is the wire nut and you being very gentle when you manipulate them back into the box, they're not actually connected. The poor physical connection creates a poor electrical connection. A poor electrical connection has resistance which creates heat. Heat creates fires. Even better after a few years when enough traffic has driven past your house and enough people have moved around inside of it and the wires have wiggled to just barely in contact so occasionally when someone walks down the hallway the lights will all flicker as the wires create some pretty electrical arc light shows, adding carbon buildup to the wires and further increasing the resistance and heat concentrated in the one tiny point of the copper where they're still sometimes connected. No reason at all for this rant. Definitely not a real example at all. Definitely didn't waste an afternoon with a toner, a drill with a pilot bit, and a borescope to hunt down the six octagon boxes someone had sealed into the basement ceiling hiding away some of the shoddiest wiring I'd ever seen. Nope.

regularfry 6y ago

Cases can have "case open" switches that tell the machine to switch off. You can't necessarily tell beforehand.

jrootabega 6y ago

Case intrusion alarms (built in or Homebrew)