Let's take a look at an eBay or indeed AliExpress skeleton Shaver I Don't know why I ended up buying this I Think it just popped up with some other listings and I thought that is super stylish I like the fact that it's all exposed for easy cleaning maintenance. Now one of the problems with razors that I normally have, this one is rechargeable instantly USBC with a little button to turn on and off. One of the problems I normally have with them is that uh, I've got very, very fine here because sometimes I stream my head and uh, this, that's the ultimate test. So I'm about to just take the beanie off and let's shave my head.

so I'll uh, bring it in here. Not bad, not bad. Okay, yeah that that is working, that's pretty good. Uh, so I'll get the rest of that later on.

Otherwise I'm going to look extremely odd something out the window. It's going to end up covered in here. So so far so good. I Want to point out I did put some oil in this before using it because that is what you're supposed to do with uh with Shavers Now how does this come apart? I See, it's got Springs here.

Let's lift the springs and does this lift off at that? It should lift off. It does pop off like that. It's good for good for Access I'm going to take these screws out now. Where's our suitable driver? here? Is a suitable driver? Maybe that's not a suitable driver.

Let's not chew the screws up. I'm hoping they've not glued everything into the interior of this because it's going to make it very hard to get out. Um, if I'm very lucky they'll have used a a technique with a sledge of plastic sledge that goes through and is being held in by these two screws. but it is the moment of truth if that is the case or not because otherwise it's going to be very hard to get this out.

Possibly hopefully this will release everything we shall find out in due course. Uh and I chose this one instantly because it's a picture of the guy with the Uh with the big beard. It's quite stylish. Is this going to push out? Is this going to push out? Oh, it's not.

It is not necessarily going to push out. I Can see it's got a split case that looks as though it is kind of designed to grip in with friction. Uh. I Like anything I can slide over this.

Um. I shall just take a hunt for something and see if I can find something one moment please. Oh, this isn't going to plan I shall use some heat in this and some air perhaps drizzle some solvent down? I'm not sure I'm guessing there's an 18650 or something in here I'm going to have to proceed with caution here. don't want to damage the battery.

Um, but I shall pause while I do this because I'm not sure how long it's going to take and then I'll get into the reverse engineering one moment please and resume. let's Zoom down a little bit. So the first thing I actually did with this before opening it was I rebuilt it and shaved the rest of my head. Since it was doing such a good job, it did a very good job.

It stalled a couple of times when being shoved into the hair too hard, but other than that it was perfectly fine. However, getting open turned to be quite difficult. I thought that this was going to be a plastic carrier all the way through and that by releasing the screws as you saw earlier that the whole lot was going to slide out. That did not happen.

It turns out the motor is actually in a plastic housing and it's kind of. The plastic housing is a little split in it here, a deliberate little slot and in the process of manufacturing they basically Ram the Mojo hard into and it wedges it out against the side of the case. Very hard to remove without using a hammer and probably wouldn't go in very well again afterwards. So I left it.

I Initially in my process of discovering that decided to heat the whole thing up after solvent is approval. alcohol and a bit of locally applied heat did not do much. so I put it in the airfryer at low temperature. It turned out to a slightly higher temperature.

It came out very hot to the point I was thinking, well, this contains a Lithium cell. This is not good. It didn't help anyway. What did help was just being.

Reckless You can see the slight scuff marks here and pulling the bottom cap off and that revealed this circuit board is loose and well, it's actually screwed into this cap. and then there is an 18650 stuffed up there with a capacity of approximately one amp hour as you might expect. And it's notable that they've soldered directly onto the ends of both ends of the Lithium cell, which is a bit naughty. The Lithium cell also has a sticky pad for insulation nutrient which is okay-ish I Guess as long as it doesn't get rammed down too hard because there are the motor connections sticking out the back down there.

Um, let's go to the circuit board which is this which is surprising. it's not what I was expecting. It's a bit kind of. Yeah, it's a bit silent.

Interesting, it's it's not a good charge secretary as such. Uh, it is very odd. Uh, it is based around a little microcontroller which you'd expect. It has a diode capacitor across the motor and the motor is Switched by an A2shb mosfet which has a 10K peel down resistor on its gate and a 100 ohm going to the processor to actually turn it on.

There is a decoupling capacitor and that's all that's in this side of the circuit board. This side is flipped to make everything sort of correlate. so that's one side of the soccer board. I'm not sure why they put well.

I'll show you another side. It's kind of strange. uh oh Thing's worth of note: they've just bonded the identification pins of the USBC connect together. no resistors.

plenty of room for them, but they didn't put resistors into signal. You know that it was a charging device and this is the other side flipped, which is why everything is in Reverse It's got a 100 ohm resistor, a J3y transistor, and a red and a green Led the USBC connector and it's got the clicky button and then this strange link. It doesn't need that. It's because like it only really needs one connection.

but that's strange how they did that because they are kind of tied across anyway. like these are two are tied across and they kind of screen printed there and they've just put I've got the pad sitting on the screen print. It's a bit of a strange circuit. Let me show you this schematic and uh, those of you who have a nervous disposition might be concerned that the charging socketry the charging circuitry is this transistor which switches the 5 volt down to the positive rail the Lithium cell.

There is no specific current limiting I think they're relying the transistor for that. It gets wormish. It gets got up to about 30 40 degrees Celsius and that is turned on by a 100 ohm resistor from the 5 volt Supply which then relies on the processor actually booting to be able to actually control the charge. Um, it's very strange.

Not sure what they were thinking of here, but let's come back to that in a moment. The Lithium cell is here. It's got a decoupling capacitor. It's got the maker controller.

the microcontroller has current limited outputs. Um, it has a button going to the zero volt rail. That's the clicky button that turns it on. Uh, and it's got the two LEDs red and green.

It's notable that uh, this pin is very capable. It's actually monitoring. it knows when there's a USB Supply is connected because uh, it's abusing it big time. It's just a bit weird.

Uh, the mosfet is here. It's got is 10K cooldown resistor for stability. It's uh, A2shb A2 S H B which is empty's favorite tiny little high current mosfet 100 ohm resistor to the gate from the processor and that switches the motor which has a little tiny decoupling capacitor across it for noise reasons and said anti glitching of the transistor. that's that little capacitor there.

plus this diode which is also across the motor to absorb the to basically shunt the back. EMF Spike when it's disconnected and the magnetic field collapses. Um, getting back to the charging circuitry. So very oddly I connected.

Uh, another battery to it that was in a low state of charge 3.15 volts and it charged at 150 milliamps. The only thing that's really limiting the current is this transistor here. Not sure what's going on here. it charged it up to four volts at four volts.

The red LED light to show its charge. but um, though, sorry, the red LED lit to short was charging at four volts. it stopped charging lithium cell um and but it still kept the red LED powered and the current from the Lithium cell actually showed current flowing to feed the circuitry. So minus eight milliamps was at that point which was basically just powering the red LED Then it dropped slow back to 2.97 volts.

Then it changed to green and at that point it dropped at minus 4.3 milliamps. But uh, that's only when the LEDs are lit because it can detect that it is connected to the 5 volt. Supply via this line, they've they've been cheating big time to get this. Um, even when it had fully completed charging, the circuitry was passing 38 milliamps on the USB Supply because effectively, to turn the transistor off, it only has to pull it roughly a wee bit below.

uh, the this rail here. Even pulling it to this rail would turn it off because the base of that transistor, which is an Npn transistor, has to be 0.6 volts above that rail. So it pulls it to the zero volt reel and that effectively turns it off. But there's a fair amount of current flowing through that resistor and through the processor and to the zero volt.

Rail And it doesn't. It's not a decisive. it doesn't pull it down to zero volts, it's just basically biasing it. so it's somewhere between the plus reel and the minus Real.

So the processor was actually getting warm at that point. Very strange. Um, other things worth mentioning about that. Yeah, theoretically there's going to be a diode, a anti-static protection diode there, which would compete with the diode in the transistor, so it's very much just delicately balanced.

That might be why the transistor didn't turn on fully and acted as a current limiter during the charging. It's very strange, peculiar, peculiar circuitry they've I mean it works. It stops charging it four volts. So the actual Lithium cell is theoretically going to last a good length of time because it's not really being.

it's not being charged to the full 4.2 volts. It still has plenty of Shaving power. Even it's a half charge. Um, and not there must I presume there's a lower limit that the microcontroller will just shut the mosfet off as well to show that uh, it's uh, detect that the battery is low air.

that or you'll probably hear the shape are getting low speed and it will start stalling quite a lot when you touch it. It's doubly here, but that is it. It's very peculiar. It's the weirdest charging circuitry I've seen a long time and I've seen some weird charging circuitry.

so these are things are quite stylish. There are a few Oddities squirmy bits, just the usual scoring bits you'd expect from Train Easy type products. It is mass produced to the hilt and the price varies dramatically. Some people are designed selling this as a designer accessory I Don't know if there's a designer brand that is expensive and then a cheap knockoff, or if it's just people price gouging it I think people are Drop Shipping these from China on eBay from AliExpress but uh, it's quite stylish.

Also, the logo. The popularity the logo determines the price the more. This one has the bearded guy with the sun glasses and the Cutthroat razors and the crisscross skull and crossbone style. This one was more expensive because obviously it's more popular for that image than the others because it's a trendy sort of uh, tattoo industry.

Barber industry types of designer steampunk accessory, but that is it. I Will put this back together now being careful about the placement of this lithium cell with its little sticky pad. um, and I'll probably use it because uh, it did an extremely good job of trimming the hair. Um, it's not bad at all in that regard, so it's weird, but it works.

It doesn't really ridiculously overcharge the cell in any way, but it's just weird circuitry. But to be fair, it does work and it's a decent shaver. It's the eBay AliExpress skeleton shaver.