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 going out to the load 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,

we're going to see 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 tiny little load cell with the

anchor point at this side from the base

and then the platin attached at one end,

the the other end here. And it's only

got

Oh, no. It's 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 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