Is there a maximum level to the measurement? Asking for a friend… “3.6 roentgen. Not great, not terrible.”
Why did I see graphite on the roof?
Flipper Zero Geiger Counter
81–86 of 86 posts
Re: Flipper Zero Geiger Counter
#82I 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 .
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…
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.
Re: Flipper Zero Geiger Counter
#83Earlier quoted context omitted.
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 c…
> 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).
Did you just invent a taser :)
Re: Flipper Zero Geiger Counter
#84Earlier quoted context omitted.
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…
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.
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.
Re: Flipper Zero Geiger Counter
#85I 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 .
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.
Re: Flipper Zero Geiger Counter
#86Earlier quoted context omitted.
I would really like to have a geiger counter that I can put on the wall and connect to Zigbee/Z-Wave/WiFi and tie into Home Assistant. I've considered building one with the cheaper tube and ESP32, but I'm surprised that for Radon and radiation, it seems like something like AirGradient, but for radioactivity, doesn't exist.
You might be interested in RadiaCode (full gamma spectrum) and RadiaCode Python Library - https://www.radiacode.com/ and https://github.com/cdump/radiacode For Radon detection options are * direct alpha detection via wet film + process (slow, and day turnover physical processing) OR optical scintillation of filtered air, or * stochastic gamma detection via a full spectrum and a formula to identify and divide out main…
I did this with radiacode and that library. I had chatgpt put together a quick little server that pushes from cdump/radiacode into MQTT for home assistant. I'd be happy to release it if there's interest.