3 ms·

I know that footguns are broadly "on-brand" for the flipper zero ecosystem, but exposing high-voltage leads like that without any warning whatsoever seems a bit

I know that footguns are broadly "on-brand" for the flipper zero ecosystem, but exposing high-voltage leads like that without any warning whatsoever seems a bit much.

superxpro12 1y ago
Is there a schematic? How high we talkin?
- colechristensen 1y ago
  Hundreds of volts
  - leshenka 1y ago
    but how many amps though?
    - hgomersall 1y ago
      How many is safe? I don't mean that facetiously - do you have a good understanding of a safe power limit on a source at hundreds of volts?
      - vlovich123 1y ago
        Depends on the specific conditions but less than 2mA for AC should only be a tingle and closer to 5mA for DC will be a slight tingling.
        JohnFen 1y ago
        > less than 2mA for AC should only be a tingle Yep, and even with AC, it depends on the frequency. There are a ton of variables affecting how dangerous electricity is to people, so it's hard to make general statements about it.
      - vegadw 1y ago
        There's a really good video on this: https://www.youtube.com/watch?v=BGD-oSwJv3E https://www.youtube.com/watch?v=BGD-oSwJv3E But even beyond that, the maximum power output will still be pretty limited. If you short the HV rails, it will almost certainly start to drop in voltage and raise in current quickly, but only to the limits of the resistance from other elements in series and the power source's output ability. I strongly doubt you could even make something dangerous from the Flipper, at least unless you attach a large cap, let it charge slowly, and attach a taser module.
      - OkayPhysicist 1y ago
        Talking a bit out of my ass here as someone whose EE experience ended at graduation, but a good general rule is if you stay below 5 mA continuous, it is rather difficult to injure yourself. For extremely short shocks (like you get when you discharge a capacitor across yourself) you can get away with a lot more than that, though. I would be rather surprised if a device that is powered off a lithium ion battery like the one in the Flipper Zero managed to seriously injure someone.
      - idiotsecant 1y ago
        Yes. Someone else already did the hard work for us on that. GFCIs commonly trip at 5mA. Pretty hard to really hurt yourself below that.
      - superxpro12 1y ago
        15mA is the limit in my brain. Im sure someone will chime in with a different number but its around here. The thing to remember is the output impedance. You can have 1000's of volts at a node, but its sourced by a VERY high impedance output. so when you touch it with your hands (which is like 100kohm on a dry day), the voltage collapses because of the voltage divider your hand created. But if the output impedance is low (transmission lines), well its game over.
ooterness 1y ago
Geiger counter with built-in taser. It's a feature, not a bug.
- wellthisisgreat 1y ago
  Fallout vibes
JohnFen 1y ago
I don't know about the details of this device, but in general, simply being high-voltage doesn't automatically mean it's dangerous. One of the machines I work with in my day job has probes that put out around a thousand volts, but it's totally safe to touch them with your bare hands. You won't even feel a tingle. That said, it's always prudent to treat any live electrical line as dangerous unless you know for a fact that it isn't, of course.
- giveita 1y ago
  Why is the 1000v safe? My guess is energy released is small e.g. a small capacitor. Or internal resistance is high so it becomes much less when you touch it. Or you mean touch one end and it is DC.
  - JohnFen 1y ago
    I'm no EE, but my understanding is that it's partially because the amperage is very low and partially because the signal is AC operating at a frequency that causes a large impedance mismatch between the probe and people. It's counterintuitive enough that the probes actually have an "anti-warning" label to inform people that they are safe to touch.
CamperBob2 1y ago
About the same voltage as a carpet shock.
emsign 1y ago
I'd highly recommend printing an enclosure for it.
burnt-resistor 1y ago
Chinese Geiger counter kits sometimes include a single piece of plexiglass or nothing at all. I have one I only use when placed inside a plastic bag, so it's not going to be detecting any α. I haven't yet put it up against my CDV-717.
madaxe_again 1y ago
Current kills. Voltage just makes it possible for the current to get into you.
umvi 1y ago
High voltage means nothing if the power source can't deliver the current. You could use a transformer to step up a AAA battery to a billion volts and it wouldn't do anything because a battery can't actually push out 1B/[your body's resistance] amps. With low voltage battery circuits the main thing you have to be wary of is capacitors because those can push out a lot more current than the battery itself. Usually you can judge how much a capacitor would hurt if you touched it based on its size. If you have a device with 20 batteries charging a baseball sized capacitor, be very cautious (like the DIY gauss guns/rail guns you see on youtube). Even a thimble sized capacitor will jolt you surprisingly hard. One time I touched the charged capacitor of a disposable camera and the discharge gave me quite the zing.
- jcalvinowens 1y ago
  > High voltage means nothing if the power source can't deliver the current It can still be dangerous though, it can trickle charge an output capacitance which will deliver the current to hurt you. A small battery only charges it more slowly, the end result is a function only of voltage (assuming the battery has sufficient capacity to completely charge the capacitance).
  - giveita 1y ago
    Did you just invent a taser :)
numpad0 1y ago
I believe it also doesn't make a lot of sense to have a real Geiger tube and have it exposed. For the sexond, Geigers are binary, they only report detection events, not types. So you don't want it to be triggered on non-X rays like interferences from computers around, and you might also want to be able to occasionally remove surface contaminants from the equipment. Both of these are easily achieved by giving it a durable opaque case which is how everybody do these. And for the first, I believe a modern photodiode taped over is by itself more sensitive than Geigers, even more so if coupled to a scintillator crystal(salts that glows in x-rays), not to speak of spectrometer based systems that can additionally tell energy levels therefore types and biological damage levels of incoming rays. The real Geiger tube running on display is cool, but that's strictly it. I believe.
deleted 1y ago
[deleted]
GuB-42 1y ago
It is significant though? The suggested board is powered by USB, that's 5V 500mA, so, 2.5W. Let's say the tube is run at the recommended 380V, at 2.5W, that's a current of 6.5mA, which is barely painful, and not dangerous. I guess that with that power, if the circuit really wanted to hurt you, it could boost the voltage in the 50-100V range for a ~30mA shock, which is definitely painful and the start of what is considered dangerous. Electric safety is complicated, there is so much to take into account: current, voltage, frequency, location, presence of water, etc... Skin resistance is far from constant. Maybe it could do more if it disregards the 500mA USB limit to the full 1.2A that the Flipper Zero can deliver, or with capacitors, but it doesn't seem to have enough of them for a significant power reserve. If it could do that, I would also worry about plugging it to my Flipper Zero or to anything of value out of fear of damaging it, as it would have to be of pretty terrible design, but well, that's AliExpress after all.

I know that footguns are broadly "on-brand" for the flipper zero ecosystem, but exposing high-voltage leads like that without any warning whatsoever seems a bit much.

superxpro12 1y ago

Is there a schematic? How high we talkin?

colechristensen 1y ago
Hundreds of volts
- leshenka 1y ago
  but how many amps though?
  - hgomersall 1y ago
    How many is safe? I don't mean that facetiously - do you have a good understanding of a safe power limit on a source at hundreds of volts?
    - vlovich123 1y ago
      Depends on the specific conditions but less than 2mA for AC should only be a tingle and closer to 5mA for DC will be a slight tingling.
      - JohnFen 1y ago
        > less than 2mA for AC should only be a tingle Yep, and even with AC, it depends on the frequency. There are a ton of variables affecting how dangerous electricity is to people, so it's hard to make general statements about it.
    - vegadw 1y ago
      There's a really good video on this: https://www.youtube.com/watch?v=BGD-oSwJv3E https://www.youtube.com/watch?v=BGD-oSwJv3E But even beyond that, the maximum power output will still be pretty limited. If you short the HV rails, it will almost certainly start to drop in voltage and raise in current quickly, but only to the limits of the resistance from other elements in series and the power source's output ability. I strongly doubt you could even make something dangerous from the Flipper, at least unless you attach a large cap, let it charge slowly, and attach a taser module.
    - OkayPhysicist 1y ago
      Talking a bit out of my ass here as someone whose EE experience ended at graduation, but a good general rule is if you stay below 5 mA continuous, it is rather difficult to injure yourself. For extremely short shocks (like you get when you discharge a capacitor across yourself) you can get away with a lot more than that, though. I would be rather surprised if a device that is powered off a lithium ion battery like the one in the Flipper Zero managed to seriously injure someone.
    - idiotsecant 1y ago
      Yes. Someone else already did the hard work for us on that. GFCIs commonly trip at 5mA. Pretty hard to really hurt yourself below that.
    - superxpro12 1y ago
      15mA is the limit in my brain. Im sure someone will chime in with a different number but its around here. The thing to remember is the output impedance. You can have 1000's of volts at a node, but its sourced by a VERY high impedance output. so when you touch it with your hands (which is like 100kohm on a dry day), the voltage collapses because of the voltage divider your hand created. But if the output impedance is low (transmission lines), well its game over.

ooterness 1y ago

Geiger counter with built-in taser. It's a feature, not a bug.

wellthisisgreat 1y ago
Fallout vibes

JohnFen 1y ago

I don't know about the details of this device, but in general, simply being high-voltage doesn't automatically mean it's dangerous. One of the machines I work with in my day job has probes that put out around a thousand volts, but it's totally safe to touch them with your bare hands. You won't even feel a tingle. That said, it's always prudent to treat any live electrical line as dangerous unless you know for a fact that it isn't, of course.

giveita 1y ago
Why is the 1000v safe? My guess is energy released is small e.g. a small capacitor. Or internal resistance is high so it becomes much less when you touch it. Or you mean touch one end and it is DC.
- JohnFen 1y ago
  I'm no EE, but my understanding is that it's partially because the amperage is very low and partially because the signal is AC operating at a frequency that causes a large impedance mismatch between the probe and people. It's counterintuitive enough that the probes actually have an "anti-warning" label to inform people that they are safe to touch.

CamperBob2 1y ago

About the same voltage as a carpet shock.

emsign 1y ago

I'd highly recommend printing an enclosure for it.

burnt-resistor 1y ago

Chinese Geiger counter kits sometimes include a single piece of plexiglass or nothing at all. I have one I only use when placed inside a plastic bag, so it's not going to be detecting any α. I haven't yet put it up against my CDV-717.

madaxe_again 1y ago

Current kills. Voltage just makes it possible for the current to get into you.

umvi 1y ago

High voltage means nothing if the power source can't deliver the current. You could use a transformer to step up a AAA battery to a billion volts and it wouldn't do anything because a battery can't actually push out 1B/[your body's resistance] amps. With low voltage battery circuits the main thing you have to be wary of is capacitors because those can push out a lot more current than the battery itself. Usually you can judge how much a capacitor would hurt if you touched it based on its size. If you have a device with 20 batteries charging a baseball sized capacitor, be very cautious (like the DIY gauss guns/rail guns you see on youtube). Even a thimble sized capacitor will jolt you surprisingly hard. One time I touched the charged capacitor of a disposable camera and the discharge gave me quite the zing.

jcalvinowens 1y ago
> High voltage means nothing if the power source can't deliver the current It can still be dangerous though, it can trickle charge an output capacitance which will deliver the current to hurt you. A small battery only charges it more slowly, the end result is a function only of voltage (assuming the battery has sufficient capacity to completely charge the capacitance).
- giveita 1y ago
  Did you just invent a taser :)

numpad0 1y ago

I believe it also doesn't make a lot of sense to have a real Geiger tube and have it exposed. For the sexond, Geigers are binary, they only report detection events, not types. So you don't want it to be triggered on non-X rays like interferences from computers around, and you might also want to be able to occasionally remove surface contaminants from the equipment. Both of these are easily achieved by giving it a durable opaque case which is how everybody do these. And for the first, I believe a modern photodiode taped over is by itself more sensitive than Geigers, even more so if coupled to a scintillator crystal(salts that glows in x-rays), not to speak of spectrometer based systems that can additionally tell energy levels therefore types and biological damage levels of incoming rays. The real Geiger tube running on display is cool, but that's strictly it. I believe.

deleted 1y ago

[deleted]

GuB-42 1y ago

It is significant though? The suggested board is powered by USB, that's 5V 500mA, so, 2.5W. Let's say the tube is run at the recommended 380V, at 2.5W, that's a current of 6.5mA, which is barely painful, and not dangerous. I guess that with that power, if the circuit really wanted to hurt you, it could boost the voltage in the 50-100V range for a ~30mA shock, which is definitely painful and the start of what is considered dangerous. Electric safety is complicated, there is so much to take into account: current, voltage, frequency, location, presence of water, etc... Skin resistance is far from constant. Maybe it could do more if it disregards the 500mA USB limit to the full 1.2A that the Flipper Zero can deliver, or with capacitors, but it doesn't seem to have enough of them for a significant power reserve. If it could do that, I would also worry about plugging it to my Flipper Zero or to anything of value out of fear of damaging it, as it would have to be of pretty terrible design, but well, that's AliExpress after all.