Wireless telephone, decafeinated coffee, alcohol-free beer, vegetarian burger, what next?

[Madmax]

Look at the manual: https://photos.app.goo.gl/VHYgaq2GQSZk5CLN7 What do you see? (drumroll)
Yes, you are absolutely right! Sensor-free dosimeter is the next. Welcome to the new era of radiation detection technologies!
Best Chinese developers worked hard for years to get this beautyful product, cutting-edge technology and breakthrough the limits of classical science.
But first it needs to be charged. Plugging it into USB...



Built-in CHARGE LED is visible through the plastic, any holes are eliminated to increase protection level. Very nice design! Charged - consumed only 170 mA*h from USB.
Now it's time to switch it ON to enable all it's magic.



[*] No reaction to radioactivity, no worries in any conditions
[*] Fights radiophoby
[*] (most loved by customers) Cheaper than sensor-based radiation detectors!
Please note speaker symbol in the up-left corner of the screen.

Let's look inside...What we see?



First seconds after opening, We can see pure Chinese philosophy, escaping out of the cramped cage of reality and spreading it's wings bearing to the blue sky. Diameter of holes in back cover is properly calculated to hold all the philosophy and magic inside, very good job.
After the smoke cleared, we see a PCB without any sensor, only an imitation - simple two glass tubes glued to the PCB. No HV, no speaker (remember speaker icon in the up-left corner of the screen?). Pure zen!
Let's try to remove the imitation of Geiger tube, just in case.



The glue is very easy to remove, good find for engineers. Yes, we were right - it's only imitation, made of high-quality glass tubes from nearest scrapyard. Red wire broken automatically during the glue removal - very nice design to prevent fire.
Let's see what's on the other side of the PCB:



Nothing interesting...Nothing?
No. Who can tell me how many and what parts can be abandoned without any changes in device's work? There are some, sure.
Who can mention them all?

Seriously, I think that production and selling devices like these is very close to criminal offence. Using of such fakes can be dangerous for health or even life. But who cares in China? They are 1 412 000 000 and still growing...What do you think?

That's all, folks! :)

[NuclearPhoenix]

Maxim,

love your post and your excitement for this type of Chinese innovation! I already knew of that device, but it's interesting to see that you can consistently get one of these (saw a bunch of people already reporting on this), so it's not a fluke. Obviously an arguably intricate scam and they can afford to do it, no chance of getting any legal hold of them whatsoever in China.

I'm suprised they went to all the effort to populate a bunch of components and even faked a GMT tube so that wary customers that open the case and have a look are deceived as well. That probably helps a lot to avoid any "undesired" refunds and I'm guessing most people that buy this kind of stuff have no deeper understanding of radiation detection and just want one for some kind of nuclear disaster/out of fear. Meaning most likely no way to actually test the device, so a nice green backgroung reading is all they need apparently :)

How much did you end up spending on this "experiment"? Maybe you could reuse the display and the LiPo battery at least.

What I'm curious about is that the PCB really looks like it came from some sort of GMT detector at one point. I've seen some with more soldered components to the back side, and at a quick glance it looks like there would be an HV supply if you mounted <all> the components? The software doesn't work obviously, but it would be interesting to see if the PCB was at least designed correctly. Looks pretty easy to reverse engineer.

Best,
Matthias

[Madmax]

Hi Matthias, Thanks for the reply.

Checked: CPU outputs 10 us long pulses to the gate of SOT23 MOSFET, it's drain connected to footprint for a transformer. On the output of voltage multiplier there is a place for voltage divider connected to the CPU, when I apply +3.6V to this point generation of pulses stops. So, under some conditions, it will generate HV. When pulses applied to the "after Geiger tube" point readings increased slowly. You are absolutely right: it's easy to reverse, maybe this is the only advantage of this device. OLED and battery are useless: it's Chinese nonames without any guaranteed parameters...
Cost of experiment was zero: seller refunded device's price after playing fool for some time. Almost all Chinese sellers on eBay behaves the same way: playing fool and trying to fool their customers. They trying to communicate like this is the first fail, all goods they sold before were excellent quality. Good indicator is seller's nickname like HoShiMin7895.