High Voltage Ionizer Teardown: Design Flaws & Electrical Analysis

[00:00:00]it's time to look at another ionizer a pink ionizer obviously and one that is slightly perplexing because normally an ionizer works by applying a high voltage charge i'll just dump that out the way complete with instructions are just stereotypical it doesn't mention anything about its operation it just basically says if it bursts into flames unplug it something like that but an ionizer typically when you plug it in usually has a little tuft of carbon fibers pointing out the front or metal spikes point at the front and it puts a high negative voltage on those spikes or fibers and it puts electrostatic charge into the air and that results in fine dust precipitating out there this is odd because when you plug it in the bristles are actually pointing directly at the wall which means it's about that far from the wall and it is effectively going to just basically create an ionic short circuit to the wall that could have unusual extra effects that might be quite useful now let me bring up the hockey the hoppy is still here i just want to reassure people that because uh i got another one that was supposed to be the more accurate version but they've sent me the wrong version and since it's aliexpress there's no chance of ever that getting that sorted plugging it in it says 77 milliamps 0.6 watts uh it's not even on the moment there's a button this is pointless in an ionizer you press the button the green light gently goes up and it theoretically starts ionizing let me just double check that it is ionizing the way to find this out is to get a meter set it to about 20 volts stick the uh one of the lead to ground well i'll stick it onto the soldering station here and stick the other lead in front of that little tuft and you should see a high negative voltage and well it's pretty much off the scale it's pretty good actually that's pretty good uh you're seeing quite a high negative voltage without me even touching the fiber emitter because it is basically creating electrostatic charge in the air good results so far uh power factor is 0.034 which is terrible that actually suggests the capacitive dropper all the button does is off and on with a it just gently positive modulates that light just ramps up and switches the ionizer module on enough let's open it that's what you're here for suitable screwdriver screw number one and screw number two i did get it in fetching pink just in case it is dangerous uh the whole reason for the pink is just because it's quite funny when things are electrically dangerous and they're pink it just adds an element of amusement to it the front has fallen off with its little captive button here is the circuit board with a big fat capacitor suggest the capacitor dropper with the high voltage output right against that i don't really fancy that much um right tell you what i'm going to take a picture of this there's a little ionizer module right i'll take a picture of this and we'll reverse engineer it and see what the circuitry is like one moment please resume with exploring this very long thin circuit board so things worth mentioning on the back of the circuit board are a fusible resistor 20 ohm we've got the dropper capacitor which has been grossly oversized at one micro farad to give it a wide voltage range so it can be used all around the world in reality that's putting a lot of stress on the little zener diode here but i'll cover that in a moment the module is just stuck in the back there is a little electrolytic 470 microfarad capacitor and the connections this case has just the metal pins going in and to connect onto them is not soldered directly they've actually used these little connectors that are designed to go in a circuit board and when the circuit board is put into the case it basically slides over those pins but instead of that they've soldered wires on press them over the pins and then they've hot melt glued them in place it's not a bad thing the incoming supply goes via that resistor over to the bridge rectifier the live goes via the capacitor in the back with its discharge resistor and that gives the rectified output which then simply goes across the electrolytic coupler capacitors and the zener diode w8 senior drive rated 0.2 watts but actually being used at 0.4 watts which is not so great gets quite hot that then provides a stable 5 volt-ish supply for everything including the little microcontroller and the module that is in the back but actually connected with these two connections here that there's not much else to say i shall show you the schematic for this that's the best bet so here's the supply come in there's a drop capacitor if you have one of these and you lived in a 200 upwards volt country i'd recommend changing that from 400 from one microfarad to 470 microfarad because that would result in much less dissipation from this little zener diode or zener diode as some people prefer here's a 20 ohm fusible resistor draw a little line through that because it is kind of fusible as well as the resistor there's a bridge rectifier there is the power supply which is just two ceramic capacitors a electrolytic capacitor and a 5.1 volt zener diode there's the mysterious microcontroller it has the button input connecting to the zero volt rail when so when you click it it just basically pulls that pin low and it's got the little led that does the fancy thing it's the most fancy thing it does it ramps that little green led up it's got a 470 ohm resistor in series which i calculated gives about 5 milliamps through that then this splodgy mess here is because i thought that it was just going to be an npn transistor because this module only takes 20 milliamps i've tested it in reality they've used a mosfet here just possibly what they had they could have used a generic npn transistor strange that they've used that but it's also got a foreign resistor which also alludes to it being an ordinary npn transistor there is a zero ohm link i'm not sure why they have a zero ohm link there strange there is there and it's going from between the positive rail and that maybe it was to tame it down in some way or maybe they i don't know why they used that and then there's a 1k resistor across the module the high voltage module and then it's just a little spike with the negative ionization i'm not sure what the 1k resistors for is it to provide a stable load for the transistor given this is a pulsing electronic load shouldn't really be needed or is it a little uh decoupling resistor across that for back emf spikes which i wouldn't really expect because the first thing that's you're going to hit in that module is a capacitor probably maybe even via a diode very strange lots of little extra features but this zener diode gets up to about 67 degrees celsius which is quite hot i mean it's not mega hot but it's still hot enough the 20 ohm resistor at the input got up to 41 degrees celsius this resistor here which is a fairly generous size got up to 470 should i say not 470 degrees celsius 45 degrees celsius which isn't negligible it's fine also worth mentioning the discharge resistor is a good high value across that capacitor and it's a fairly big beefy one for surface mount aspect so it's not too bad let's take a look at that in the flesh yeah it's quite big they've not used the tiniest they could as many others do so that's it to be honest they could get rid of all that they could just got rid of that and they could have just slapped that straight across the supply and uh it because you don't need to turn an ionizer on and off you plug it in the wall and you leave it on now here's an interesting thing if you have well i'll just i'll doodle this on another page turn the page over and doodle so at the moment and i shall zoom out for this if you have this plugged into the wall you would normally if this is the wall i'll just draw it like that a general ground plane even if it's plasterboard or sheetrock it will still be relatively well grounded so you might have a socket on the wall and this is plugged into it and then here is the ionizer module normally you'd either of the bristles coming out the top or usually out the front so to put the negative charge into the air but the fact they've actually got it just protruding out the back creating a dead an ionic short circuit uh to what is effectively a grounded surface even if it's a insulating material at the voltages we're talking about the ionization it will have that effect i'm just going to tame this down a bit but what that does pose an interesting thing here because it does create an ionizing short circuit you might get a slight corona discharge on these needles because of the high current flow and that will result in trace levels of ozone as opposed then that if this thing does warm up very slightly it's not really going to warm up that much but it could create an airflow past and that could just basically add a tiny trace of ozone into the room it's odd it's a strange design it's almost like they just copied things and did what they thought was the right thing and it's just odd definitely the on off button and a microcontroller just basically to turn this on and off and like an led just seems odd because really you should just unplug it from the wall when you don't need it but an ionizer draws so little power that you can just leave it plugged in all the time the module itself i'll get the kink calculator for this i measured it at about 22 milliamps 0.022 milliamps at 0.022 amps 22 milliamps times the voltage it's operating at is 5 volts the module itself only draws 0.1 of a watt so uh by the time they've finished with it the zener diode is dissipating a lot more than the module itself can significantly more that's very strange but then again this is no surprise strange pink things from china but there we have it uh a strange ionizer that points the wrong direction and has an on off button for no good reason that is it quite interesting a fairly neat design inside but seemingly completely and utterly pointless