There has been an evolution of the revolution. This is a ambi pure. Well, it's procter gamble. I think make this it's pro.

Yes, it is procter gamble. It's an air freshener. Well, they say an air freshener, it aromatizes the air and it takes these little bottles. They're.

Quite stylish, i have to say you basically unscrew the caps of each one making sure you don't get in your finger because it's incredibly unpleasant and it has what they call complementary, smells very hard to tell difference. And in the case of this new unit, you slot it in like that and it alternates roughly 45 minutes per aroma, but when you plug it in, let me just plug this in right now, you'll see the leds, they are going through a little sequence and then It stops on one now. This claims to have smart programming. The smart programming, as far as i can see, simply relates the fact that it has a facility to detect that the cartridge is missing.

It's got a little switch in here and it might be able to detect when it has been changed, but does it have memory backup inside or something like that? Certainly if you plug this in with nothing plugged in it just carries on as normal. It presumably heats. The chamber, so i thought maybe there's a some memory system that uh, if you unplug it holds a charge for a while. So when you unplug a car, you can plug it in it.

Uh knows that there's a new cartridge and uh, it just stores at the memory for long enough to charge low enough to detect that. But it also says this thing lasts for 90 days, if you only use it for 12 hours a day at the low setting. This these aromas, and that means it would be off for quite some time. So how is it actually storing that memory? Tell you what, before going, if i'm going to get these lids back on, because the place is absolutely stinking of spiced, appley type, aroma type stuff there we go.

I have contained the spiced appley aroma. I mean it's, not bad. It's vanilla-ish it's odd, but the only way to find out is to pop the lid off these. So i shall open this new smart programming one and we shall explore.

What's inside, i have a drill. It's heat stick together by the way you can't just unscrew it. Oh, i think i may have overdrawed that one and that one, i'm being very, very reckless, as if i just don't care, also making crunching noises. I think it may be ambipure sad programming there.

Oh, what do we have? What do we have? Here's? The switch that toggles that here is a little plate inside where's, something to lever and hack at that with. Is this going to come off? What holds this on? Oh, i think it's coming off. Oh that's! Uh held on by these rivets that i completely failed to drill out properly. Oh that's going to be allowed right.

What do we have? We do have a little switch here right. Let's investigate this right, tell you what it's photo time. One moment please wow! This was interesting to reverse engineer. It does have a memory courtesy of this little capacitor here.

So it knows if you take that unit out the wall even for a prolonged period of time and then remove the cartridge, it's very clever, to reset the timer when it's powered up again, so this side of the circuit board. I flip the image over. So it correlates to what the other side it has the power level setting of which it's got three positions, but only two actually signal to the processor. If it detects that neither positions are selected, it goes to the highest setting.

It has a 40 milliamp quick blow fuse. It has a couple of current limiting resistors for the low voltage supply, which is around about 5 volts. It has the half wave, rectification, diode and i was expecting thyristors, but it's actually got transistors here. It's interesting to note that it pulses if you select the lower power setting the fill setting.

Just has them on all the time, but sequence sequences through them, 45 minutes roughly each. But if you set a lower setting it pulsive modulates at only about eight hertz. So it's just pulsing them continually at low speed. It's quite interesting and we have the leds up here and we have the switch.

The switch that up in the cartridge is inserted, is normally open, but when it's a out like this, it actually shorts. So that switch is shorted right now. The other side circuit board shows a second diode. So that's the in-going diode, then a second diode in series, just a belt and braces approach, i'm guessing, and then that feeds this of what you might call the high voltage bus for the heaters, but then also goes through those resistors over to a zener diode based Uh power supply over here to feed the chip - all that's really in the back here is uh the transistors and a couple of resistors per transistor, one resistor per led which are independent and then the clever bit of circuitry down here.

So if you want to take a quick snapshot of this, it's not going to be easy to reverse engineer in the sense that the tracks are quite hard to follow because they're quite thin, but let's bring in the schematic of the unit. And it's clever. I like this, is this a bit too glarish? No, it's not too bad incoming supply via the two diodes uh feeds that common uh unsmoothed bus for the heaters. The other connection goes via the 40 milliamp fuse, and it's actually affect the common zero volt rail.

For the circuit ref for the circuit reference throughout the whole thing, each heater has a transistor with a 47k pulldown resistor on its base and a 10k resistor to the microcontroller to actually turn that transistor on what are those transistors? Let me just remind myself what they are: mps a44 mps, a 44 400 volt transistors with a gain of about 50 to 200. After the three heater blocks. You've got the two 15k dropper resistors, which will limit the current and then it's capped to about say five volts, but 4.9 volts is what i measured across this zener diode there's a little decoupling, capacitor and there's a hundred mega fired, smoothing capacity to provide us a Fairly stable supply for the rest of the circuitry, the microcontroller controls the heaters, but it also controls these leds independently. That means it can have the led just lit saying this is active, but in reality behind the scenes, it's pulsing the heater for that one on and off to regulate its power and they've got a 4k 7 resistor and series at each just to keep the current Down just so, it's not glaringly bright and also just to because it's a very simple power supply.

The aroma level setting is two pull-up resistors 47k and a switch that goes to the ground. I've just drawn the ground block there in the ground block here. The zero volts and it can switch either between low or medium or in the middle when it's not connected either it's high. So if either of these goes low, it will select the appropriate level, but if they're both floating it goes to the high level.

Now we come to the very clever bit the microcontroller can turn on this transistor. Here i didn't write the value of those resistors in. I should have they're 10k, so it can turn this transistor on and when it does, it connects the top of this capacitor to 100 microfarad 10 volt to the positive rail via a diode and a current limiting resistor. The resistor is there just because symbol, power supply.

Just it doesn't need to charge capacitor very quickly, so that just takes any sort of peaks and spikes of disconnecting it directly away. So this capacitor is charged up, but when this transistor is turned off or when the unit is unplugged, the capacitor can't easily discharge and the capacitor is connected to the gate of this mosfet and because mosfets are voltage driven they're. Not they don't pass much of any current. I mean it will be microamps nano amps picoamps, it's very low leakage because of that, and because the only places that current can uh discharge, this capacitor are its passive discharge current via that diode, but also it would have to be via the transistor.

That's turned off and via the gate of the fet. In reality, this capacitor will stay charged for a very long time. Literally. You could go back to days later so that does allow you to on that allows them to do their.

You can unplug it for half the time each night or turn it off the wall for for half the day, but it will still retain that memory, the point of which it won't retain. The memory is that if you take that cartridge out, if you pull the aroma bottles out, that switch will release and when it releases it will bridge 100 ohm resistor across that capacitor. It will discharge it so that when you plug the unit in the microcontroller first will test a very weak pull up in this mosfet and if it detects the mosfet, is on effectively pulling down. It knows that there's still a charge that capacitor and it knows it's uh - still get the same.

Cartridge nobody's actually pulled the cartridge out of it. Yet after it's done that just make sure that's topped up it will then, after it's done that test. It will then turn on this transistor for as long as is needed all the time, probably just to keep that topped up the reason it's even able to do that in the first place is because it has to test before topping that capacitor up. It has to test it first when you first plug it in, and so that's basically how it's got that memory.

It's very simple, very neat, simply the very low losses of this capacitor and that's how it stores the memory, i'm not sure how long it store that, for it does mean that if you left unplugged for a very very long time, technically speaking, it would gradually reduce To the point that it would say that it would think it's got a new cartridge, but in reality it wouldn't really matter because uh people would detect when the smell had reduced and did check and see if the cartridges were needing replaced. But as it is, it counts when it knows uh when the cartridge is present has been present continually between operations. It also it computes internally from the amount of time the heaters are operated um and it has an average just to basically tell you when the aroma cartridges are likely to be quite low by flashing leds, and at least at that point you could go and buy A new set, if you liked filling your house with stinky smells, but there we go. It's actually a nice design.

It's laid out. It's got lots of logical things to it, uh it scores quite high. As far as i'm concerned, that was really quite nice and this custom structure for the resistors. Those are probably standard, resistors ceramic ones, potted in with more ceramic material into the little heater blocks.

That's very neat, so that is it the uh revolution, the new smart data, one it turns out. It is actually quite smart.