Inside a smug drugglers secret scales

At first glance, this may look like a car remote control key fob, but in reality, it's actually a disguised set of micro weighing scales, presumably for measuring very expensive powders and resins in the street, but also for spontaneous measuring of the weight of jewelry and carrots. Now, let me zoom down in this and I'll show you how it operates. So to turn it on, you press this button here. It also acts as the tear button. T A R E. That actually supposeding you had a 10 g weight in it. If you press tear, it will remove that from the weight so that any future weights will be based on minus 10 g. Um I'll tear that back to zero. We've also got the M button which selects between the various uh units it can weigh in, including um carrot and ounce. But as it is, let's pop the weights on. Oh, before I do that, I'll just show you that it's got a much darker display when viewed from the front angle than it does directly from above. It looks quite dim on the camera, but that's okay. So, I'm just going to zero that and then press a 50 g weight on. And it shows the 50 g. A 20 g weight shows suspiciously accurate 20 grams. A 10 g weight shows an equally accurate 10 g and a 5 g weight shows 4. 99 which then corrects itself conveniently to 5 g. I get the feeling it's just, you know, cheating a bit for these calibration. However, should you ever have to actually calibrate it, here's how you do it. Press down both the buttons together and after a while it will display well it's displaying five here but you can switch through. So it can be it's capable of doing very accurate measurements apparently. You can calibrate to 1 g, 200 g, 100 g, 50 g, 20 g, 10 g, 6 5 or 1 g. So, I'm going to go to the 50 g option and then press um I'm having to hold it still here. It goes into calibration mode, flashes the 50 show to show that it wants the 50 g weight. You place the 50 g weight on. It pauses, it says pass, and now it's displaying the weight of the weight. Excellent. So, you could actually miscalibrate it if you so desired. But anyway, the bit we're really interested in is what's inside. You see a typical load cell is like this. It's a bit of metal in this case it's an aluminium alloy and it's supported at one end and then you apply weight downwards at the other end and by the measuring the distortion of two load uh strain gauges either side well four actually it gets a measurement and another option for that is this which is a weighing scale foot which is a it's supported at the side and when you stand in the scales it pushes this central steel bit up and deflects it and it can measure that. But how are they doing it in such a small space in this? Especially when you've already got some of the space taken by a battery in the back here, which is a 2032. So, there's not really an awful lot much space left. I can already see the load cell in there. So, let's uh unscrew this. I'll just stay zoomed in, even if it is probably going to be super potato vision at this distance. So, here's one screw. Hoping that this hinge is open. Oh, maybe there's another screw underneath that quantity control sticker at the back. Hold on. I'll soon find out. I shall rub the quality control sticker. Anything underneath? No, there's nothing underneath it. Excellent. So, let's get that screw out. Push these to the side. And then I presume it's clipped together as well. Where is my spudger? There's a spudger. This is where it never weighs accurately again after this. Right. So, the circuit board does everything on it and it's just got a how many wires are going out to the load cell? It's got four wires cell, which is fairly normal. Right, there's a couple more screws I can take out here. And then I'll take a picture. But to be honest, what we're going to see here, the LD LCD display and a blob chip. Maybe a dedicated um load uh sensor load cell chip because it is quite a specialist thing. So, this comes off, right? And I'm guessing now that if I undo these screws, the load cell is going to

come out the front of the unit on the platin. I'll just slide these wires. They've tied them. No, they've just twisted them. Right. I tell you what, let's uh untwist them and we'll thread that through. So, there it is. It's a tiny It's literally It's a miniature version of this. It's just this tiny little load cell with the anchor point at this side from the base and then the platin attached at one end, the other end here. And it's only Oh, no. It's got both. It's actually got them on both sides of that. That's really interesting. Okay, what do we have for the display? I think the display might be still in the unit. Is it? The display is There's the LCD display in the zebra strip. Here is the backlight. I wonder what the little red wires were for. What's the circuitry? Oh, right. Tell you what, there's not really much to see. I'll take a picture of it and show you what it looks like. So, I'm guessing this is based on a dedicated chip. There's so few support components. It may have some element of programmability, but I think it may just go out as it is with a standard LCD driver on board preconfigured as a set of weighing scales. The only resistor in this whole circuit board is the 47 ohm resistor for the backlight. Um, we've got a couple of buttons pulling down to the 0 volt rail. We've got some supply filtering capacitors. And this one is connected between the incoming positive from the uh CR 2032 lithium cell and the 0 volts. And this one is also referenced to 0 volts. I'm guessing there's an internal voltage reference. These two capacitors seem to the connections going straight under this blob where the chip is. And the signals that come in from the uh strain gauges actually just go straight into the chip. So really there's not much to explore here. It is ultimately just a mass- prodduced and dedicated unit. And incidentally, I did uh put it all back together afterwards. And it still reads accurately. Very neat. I love the little tiny load cell. Here, I'll give you a zoom up of the load cell. Look, here's the big one. That's literally what it looks like inside there. Complete with a pairs of holes at the end and the little strain gauges mount to the side, but so much tinier. Very neat. I like that. So, there we have it. Um, what's inside your local neighborhood dealer, jewelry dealer obviously, inside their scales? And the answer is, um, not much. It's just amazing that they've crammed it into such a small space. Now, one thing worth mentioning is that when I was putting this back together again, I did notice the most critical bit here was uh, aligning the plate up because as you tighten the screws, it can take random positions. I think in the factory they probably have a little cup that sits around this just to hold in alignment and in position while they screw it in. And the wires, I like the way that they basically they've got long wires that are tacked to the circuit board, but then they just scrunch up the residual amount on both the backlight and the uh the load cell and they just stuff them into little channels for them. Very neat. Very strangely, bizarrely simple, but ultimately when you know how it works, it's really not simple at all. That's the magic of mass production.