Exploring a popular Japanese air purifier.
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- เผยแพร่เมื่อ 6 ก.ค. 2020
- This device is hugely popular in Japan and India. It claims to clean your home environment by creating charged molecules of hydrogen and oxygen from water in the air, that are then surrounded by water molecules until they find airborne contaminants like spores and viruses, and by extracting a hydrogen atom from the target they disable it, converting back to water in the process.
Sounds wonderful, but is hard to prove without a hugely complex lab. What I can prove is that they produce trace levels of ozone. But I'd like to stress that the levels produced are very low and diffused thoroughly into the air by a powerful fan system.
These are most certainly not in the league of the ionic breeze type air purifiers that put out undesirably high levels of ozone. I'd describe the plasmacluster units as putting out a level on a par with natural outdoor air.
Many of the marketing videos show excitable Japanese youths running around in white overalls demonstrating how the units can remove strong odours applied to thin fabric sheets, defeating the smell abilities of tracker dogs. There are also timelapse videos showing things like a piece of bread remaining mould free in a sealed container with a plasmacluster emitter, or a setup passing a mist of flu virus through a chamber with a plasmacluster emitter and showing reduced petri dish growth.
But as I demonstrated in the video, that is partly - if not completely down to the smellable ozone concentration in an enclosed space. (You can smell ozone at just 0.1 parts per million.)
The construction inside this unit is amazing. Totally over-engineered to the traditional Japanese levels that we'd expect. From the power supply and control PCB to the breathtakingly beautiful emitters with their strangely retro, but time tested circuitry - everything is just well engineered for reliability and safety. Although made in China, it's definitely made to strict Japanese standards.
The fan is a low voltage electronic unit. Most likely brushless with four connections for power, control and probably feedback. It also has a thermal fuse which breaks power to the fan and plasmacluster emitters. It's surprisingly quiet, even at full power which it ramps up to in distinct steps. It pushes through a huge volume of air to diffuse the treated air into the room.
The emitter units are very intriguing. There are a multiple of modules used per unit, probably according to the space it is intended for. In this unit there are four modules, but it alternates between two pairs at a rate of about 1Hz. This may be to spread the duty for longer emitter-needle life.
The emitter circuitry is powered at 12V and has polarity protection. Internally the voltage is stepped up in two stages, firstly to about 100V where it charges a capacitor until the threshold of a SIDAC is reached, whereupon the capacitor is dumped through a high turn ratio high voltage transformer to step it up to a level where the ionisation/corona can occur at the needles.
A particular oddity is that there is no reference to mains ground, but instead the metal rings in front of the needles are connected to one end of the high voltage winding and the two needles each have their own high voltage diode referenced to the other end of the winding in opposing polarities, so that one needle is active on the positive pulse and one on the negative pulse. This does result in a separate positive and negative charge appearing in front of the emitter units simultaneously, but probably as alternate high speed bursts.
The needle in front of an opposite polarity ring does predictably result in a slight corona discharge and the resultant low level ozone production.
So my thoughts on this unit? It's really well made. The circuitry is formal and there's a surprising amount of protection built in. It's very hard to test whether the unit does produce the plasmacluster effect they describe. My own thoughts are that it is a well engineered ozone generator that produces a level of ozone similar to normal outdoor air.
Ozone occurs in nature and has an important cleaning effect in the environment. In a sealed building with no natural airflow, any ozone that enters with outdoor air is quickly absorbed by contaminants leaving the air "stagnant". As such I approve of ozone production at naturally occurring levels, and the use of a powerful fan stirring that into the air is a good approach.
Sharp may be trying to avoid the attention of the faux medical "experts" who like to loudly announce that everything causes cancer.
These machines only create naturally occurring levels of ozone in the air.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
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This also keeps the channel independent of TH-cam's advertising algorithms allowing it to be a bit more dangerous and naughty. - วิทยาศาสตร์และเทคโนโลยี
I love circuit boards that label everything.
This and many japanese products are well thought out and clearly labeled. If it is meant to be repairable, circuit boards are often labeled to prevent ambiguity.
You'd probably hate most of my quick one off PCBs I get made for various projects :P
@@jagtan13Helps that random Tech in the field.
If you want to be sneaky (insert fruit-based tech here) just label everything wrong.
Is kinda like coding everything is better when is labeled so is easier for other people to decipher. I agreed!
As an automation lab tech by education my relatively educated guess is this: The coronal discharges do generate charged ion radicals in the air, which will attract water molecules around them because of water's dipole moment. By having both needles sufficiently far apart and isolating the positive and negative discharges with some distance between them, the flowing air current from the beefy fan will prevent immediate recombination of the naturally reactive positive and negative ions and giving the water molecules enough time to cluster (at least somewhat) around them. This is clearly meant to be operated in environments with (very) high relative air humidity (which is the case always in Japan). Of course, a coronal discharge doesn't discriminate against what molecules it attacks to create the radicals, and you will therefore end up with trace amounts of ozone as well when it ionizes O2 which can recombine with another O2 molecule to form O3, even though that would not be its primary goal. I'm not sure off-hand of the reactivity and attractiveness of O2 versus water molecules to the ions created. I'd assume that in dryer climates, the O3 production would also be higher -- how humid is it in your area?
He's off the coast of Britain, so very wet.
That's an interesting read though mate.
Would've been a good idea to have a chamber with water that the air would run through then.
That is the most beautiful PCB that I have seen in a long time.
That´s what I love about Sharp. Not all companies work with the same level of care.
Thought so as well. It looked so nicely old fashioned, but at the same time very clean, tidy, beefy and reliable. It looks aven like something worth reparing instead of throwing away.
That is more the reliable technology that took us to the moon than the one that drives us around every day now. Back then we relied on the technology, looking at modern cars, technology makes you rely more on the AAA or ARC ;)
Even allowing easy disassembly with all the plugged connectors and only the replacable clusters beeing throwaway items as they are designed to be consumables.
I guess alot other companies would have saved a lot of money by getting rid of most of the connectors, especially the ones in the potted cluster modules.
Yep would agree.
Exposed gold surface on the PCB is a guard ring. Essentially the idea is to keep the voltage around the very high impedance charge sense "antenna" roughly the same as the antenna voltage itself, but at a much lower impedance. That way the leakage from the antenna section to other parts of the design is reduced significantly, and results in more accurate sensing.
I was going to post the same thing.
@@Graham_Langley Worse yet I said the same thing before scrolling down. Well, you guys are smart!!! ;-)
Dang it...
I remember the last time I forgot to replace a worn plasma cluster module.
The deathstar was lost that day.
HA! Thanks for that!
I know that feeling.
My whole ship was killed by a cadmium radiation leak caused by a poorly replaced plasma cluster module. Just as i was explaining to the captain why i hadn't replaced the plasma cluster module correctly.
Yea you need to keep on top of this to prevent a fluxed capacitor ;)
These aren't the diodes you're looking for
I got stranded in the Delta Quadrant for a decade.
"Mini avalanche of components" Finally the correct name for an phenomenon I encounter so often.
As someone living in Japan I can tell you that these things are super ubiquitous. Almost every place that has an air purifier is this sharp one
The op-amp:
The ring that's run around the input pin (non-inverting) is called a guard ring. The op-amp is set for a gain of one. The output is the same voltage as the input. With the output (via a 10k) surrounding the sense input pin it creates a very high input resistance, and the guard ring prevents the sense signal from leaking out.
They might be running the HV and sensing the amount of ozone created. When the ozone gets too high, it shuts off or alternates the modules to discharge the ozone.
That is exactly what i wanted to say. Looks like "gold" antena checks the output performance of ionizing cluster. Maybe for maintenance reasons, or maybe to check if the ozone level is not to high, so device schut down cluster for short time. Efficiency of ionizing devices warious for many reaosns, so maybe device is trying to maintain ozone level on safe level.
N
@@piotrrasz But that doesn't measure ozone. What it does measure is ion-balance. The real question is, WHAT GOES BAD WITH TIME? Why does the module need periodic replacing?
Sharp makes some amazing home comfort appliances. My Sharp 11,000 BTU portable air conditioner is an amazing unit and it purrs like a cat at 40 decibels. They use truly high grade plastics and internal engineering. This is way better than most portable AC units made in China that use the cheapest plastics.
I didn't know Sharp was still in business.
I really like the stuff they made in the 80's.
Aurthor Thing They make microwaves, fridges, air conditioners among other things.
They are still strong in Japan. They make phones(really good even if they are based on other brands) they also still developing new technologies(first company thay created bezel less phone) their smart TV are also good quality and simple. Also they still do all rtv/agd stuff.
They are still active because they have lots of their own patents and technology so they can keep up with others on Asian market.
Ghetto blasters of the 80s were great! Sharp, Aiwa and Fairmate were the brands of the period.
@@jurivlk5433 yeah, the small boombox is what I remember the most. I wish I still had one.
@@paranoiia8 I don't see them anywhere where I live in Oklahoma. This place is stuck in a bad place.
This is safely designed, but remember most Japanese outlets are ungrounded, and many Japanese devices draw high amps because they run at only 100v. Cables come with ground leads, but hardly anyone connects them. Not to mention half the country is on 50hz and the other half on 60hz.
I never really paid much attention to it, but I live in Japan and just looked up at my aircon and sure enough it's got one of these integrated.
Thanks for the great video!
The one time you saying taken to bits was extremely accurate 😂
"This is thunderf00t territory" you're the man Clive. I thought i was already subscribed, turns out I wasn't. Fixed that. Cheers
I love thunderf00t.
I have one of these I bought off eBay and refurbished. They are good at gently eliminating odors, and are an alternative to UV-C based purifiers, or activated carbon. The ozone production is not significant. It removes odors and kill viruses by indirectly producing hydroxyls. Very different from the standard negative ion generators out there.
The engineering behind this product is astounding in how thoughtfully it has been put together and how well it works.
Damn, I do enjoy your videos. Thanks for taking the time to entertain and teach. Love how you explain the circuits in great detail.
The last bit of circuitry you pulled is a very high input impedance buffer for measuring the electric field. The ring around the outside is a guard ring. By keeping it at the same potential as the voltage being measured there will be no leakage currents between "antenna" and the ring. It is there to reduce the effect of any possible surface leakage on the PCB. Download a copy of the Keithley Low Level Measurement Handbook, it has a section on guard usage.
It'll be needed due to the electrostatic nature of the detection and the need for a relatively high impedance.
I feel strangely sentimental about Sharp, for some reason.
One of my first ever cassette-recorders was a Sharp one but I think I really started to appreciate them back in the 80s/90s when they produced some really well-made VCRs.
Same here! :D
Same, and it was awesome quality.
I believe they still make good quality stuff. They are still one of the biggest manufacturers of LCD and OLED panels as well.
They also sponsored man utd
@@JG-nx3jg Well, nobody's perfect.
I like the quality of that PCB. Labled to the end.
5:52
I once took apart a 90's Mitsubishi ECU, they used a few satellite boards. Good to see Japan is still designing/making stuff with such quality.
The protection ring on that opamp sensor board is pretty nice looking.
Interestingly enough my washing machine does the same cycles: short cycle CCW, short cycle CW, then halts, then centrifuges in one direction, repeat short cycles and centrifuges in the other direction.
That has a clear purpose though, to mix the clothes on inside to outside or shift them a bit, to get as much water out as possible.
finally a circuit board that looks organized and not with the goal in mind to make it as cluttered as possible
The fascinating world of ferocious Big Clive. Love your videos and the information!
I generally have no idea what you’re talking about but you say it in such an interesting way that I just continue watching.
I would love for you to do a teardown on an Oster Blender, the kind with 10 buttons on the front. The motor has multiple windings but the button control has some magic in it. The buttons are mechanical but manage to hold hidden state. Amazing.
There’s a stamped metal slider also called a gate that runs across all the plungers of the buttons under the cover. When you depress any button, it latches, and then when you depress any other button, it pushes the gate sideways, and the gate is setup so that if it moves sideways, it releases the latches on all the buttons. A little bit of ingenuity ensures that the gate does the releasing only for buttons not being actively depressed. But it’s a rather simple mechanical arrangement and very common in button clusters :)
Clive. Your description box is beautiful! Very well written to!
Thanks. I had more to add, but hit the character limit for the description.
27:15 I was worried that the screws were going to short out your photograph...
Wow, such a high quality bit of kit. Looks like it was made to be repaired, hence the huge self tappers for the plastic screws. REPAIR EVERYTHING!
I think that this is a great and interesting piece of reverse engineering from big Clive, a video worth watching!
I have a much larger and older one of these that has a HEPA filter and a carbon filter in it as well. Works extremely well for removing cigarette smoke and also seems to help during allergy season.
The last pcb is actually the most interresting one.
MiniFig666 is right about the guard ring.
the high impedance input signal is connected on the non inverting input of the opamp.
The output voltage is (Theoretically exact) the same, and is set on the guard ring surrounding the input signal.
Because these voltages are (almost exactly) the same the leakage current is (Almost) 0.
If the output of the opamp is not exactly the same(Input offset voltage), this results in a small error.
Also the Conformal coating does not cover the guard ring. (Mask layer in KiCad)
This is because it is not a perfect isolator, (according to wikipedia) it is
breathable and can allow trapped moisture to escape.
So for preventing these sub uA currents to occur, no conformal coating on the guard ring
and the input within this guard ring.
The gold top layer is for prevention of corrosion of the bare copper.
It seems like the Opamp is type BU7262F is made by Rohm, dual opamp
supply voltage 1.8V to 5.5V Rail to Rail input output, 2MHz GBW opamp, with low input bias current 1pA typ and Input offset voltage max 9 mV
The resistor marked HI and the capacitor in parallel act as a low pass filter.
The 10K to the non-inverting input and the 10K to the inverting input are made the same value to reduce errors in the opamp. (See opamp books) This circuit has gain=1, independent of the 10K resistor value to the inverting input.
The last 10K to the guard ring with the capacitor is also a low pass filter.
This might be helpful too: microchipdeveloper.com/opamp:leakage-currents
The Unity Gain Buffer (with a guard ring)
I am a bit curious if the output signal is just a slow changing DC signal, or if the switching frequency of the Ioniser is visible in the output signal.
It might be as Clive suggested, the program can check by switching the different ioniser modules, if the amplitude of the Ioniser frequency is constant enough to check if one or more modules has failed, and if so, go in some error mode.
Nice teardown Clive!
Thank Clive. Its beautifully put together and quite clever, I'm not totally solid on their description of how it works to me its an Ioniser for sure but the positive/negative charge swooping is quite an odd one, you would think that they would cancel each other out but clearly, it works so not sure. Interesting though.
Hi BigClive!
I have one in my possession and I have had it for some years and it still runs today. I have taken it apart a couple of times to clean it up.
@@alexanderconnell800
???????
@@acmefixer1 I had a similar one (PureMate pm200) and the crap it pulls from the air tends to gather around the needles and the high voltage ring,
At this point you can tell its still working but not as efficiently,
Brushing with a soft brush to remove the 'soot' rectifies this, obviously Sharp don't want you to know this so they can sell replacements, hence the sensing plate and 'replace module' warning light,
I bought one of these from eBay UK after Clive mentioned them on a live stream, so I can wire it into an existing tower fan, search for 'IZ-CA10E' seller is 'amberliekirkham' price £12
It does look like a nicely engineered, if dated design. Even though the IC has a 2009 date code, the design being mostly leaded components seems to be about 20 more years prior - more VHS era.
the pcb silkscreen showed it was made between September 14, 2009 and September 20, 2009
You don't fix shit if it ain't broken tho
@@glennachten6515 Their patent for a "differential ion generator" is 2006: patents.google.com/patent/US20080250928A1/en (edit: application anyway; status says abandoned)
@@glennachten6515 If it works, and if the old style components are still available there is no reason to change the PCB design.
Lesson for today: You can't beat yester years quality with today's bullshit work
This really is a fun circuit. Since this video came out I have been messing around with it in a simulator, and boy does the simulator not like it. I had to simplify it quite a bit just to not crash the simulation the first time the blocking oscillator fires a pulse. Playing with the layout a bit I can't help but note the final voltage amplification stage is the solid state version of the same simple LC tank circuit that tesla coil enthusiasts have used for decades. Really good stuff.
Which simulator were you using?
@@cheyannei5983 www.falstad.com/circuit/circuitjs.html - its a fun toy; great for playing with concepts. However, its not too hard to bump into its limits.... case in point. It really didn't like that circuit at all; not until I reworked the oscillator to inject its output into a floating tank. Then, once its working, it kind of sucks because the time between rings is very long compared to the ringing. Makes you want for triggers.
Very nice industrial design, it's quite stylish!
when you watch this drunk, clive-s hand movements are quitre interesting and
and what ?
@@U20E0 Do you really expect me to remember
@@aflockofseacowsesquire that iss stupid
3 months until punchline
lovely design.
VERY nice piece of kit that! Sharp do produce some very good (and surprisingly durable) consumer electronics.
Actual quite good design of the machine itself
For once it’s not a 3 pence pcb from China!! Love it, that board is designed exactly toothe book gotta love the Japanese
The transformer graphic at 5:01 is just adorable.
I tend to ignore all sorts of non-filtering air-cleaners, preferring the ones that pass air through the filter, but this looks quite intriguing. I recall seeing this grape logo used on something in a Japanese hotel, probably on an air conditioner. Online i saw even stranger Sharp "portable plasmacluster ion generators" being sold, the size of a mobile phone. That definitely would be an interesting disassembly.
Air purifiers are common in Japanese hotel rooms, they are usually bigger floor standing units with a big HEPA filter and humidifier function, the Sharp models have the Plasmacluster stuff too.
I just veered off and clicked on the Show more button for the discription. My Lord Clive! You put a lot of work your video's!
Only the squares don't subscribe ;)
You had my attention at "plasma cluster module" ;)
Sounds like they're using a Bose technique of "Better sound through advertising"
As an ex tv repairman (crt and plasma) , thats a thoroughbred sharp unit. The part number says it all on the top right of the componentside of the PCB
I have a multi-function purifier I got from amazon years ago, it has one of those charge needles as well as a PCO segment, hepa filter and ozone generator plate.
I usually only set it for PCO or at most low on the ozone setting- it does help keep down dog or cooking smells in the house- big problem with them is there is nothing to stop someone from using it incorrectly and accidentally poisoning themselves as there is no monitor to shut down if levels get too high.
Basically, If you walk in from being outside and you can smell Ozone AT ALL, there is too much of it, if it smells like bleach you are poisoning yourself.
Fascinating - tempted to buy one.... Knowing how well made these are makes it seem worth buying a used one for cheap!
I'm in the same boat
I have a bunch already and they are pretty good
old scool electronic, LOVE IT !
The opamp monitor circuit shown at the end of the video. There is a guard ring around the sence electrode it is driven by the amp output. This is boot strap function that reduces the leakage away from the electrode. The same technique is used to reduce the screen capacitive loading on a high impedance transducer. The over all gain must unity or less or it may well oscillate.
Nice collection and presentation.
If I may add to page 15:00
It is a fly back pulse oscillator by primary1 and feedback1.
The SEC1 is the fly back winding,
and rectifiers D1,2, PRI2 47n, Zener,47n are used to eliminate negative wave cycles from reaching the SEC2.
Very nice unit
Nice Clean and do I note green water resistant mdf worktop? (aka useful level surface) just needs a skid mark & logo ;)
Clive, could you do a teardown sometime on a radon detector? Do they work similarly to a smoke or CO detector?
That is a beauty of a board layout =D
I just bought a medical grade air purifier from Austin Air called the Healthmate Plus. It's got a 5 year HEPA filter with a carbon filter. Tops of the line
Very retro with that SRBP PCB, none of that FR4 rubbish :)
First off, great work here. You are the only video on the entire internet doing this stuff. This is awesome for curious people. Being an owner of a purifier from Sharp I can definitely say it works and works best when humidity is optimal. When the heater is on and humidity is low, this is next to useless. But with good humidity, it works! There is definitely studies confirming that plasma interaction with water produces ion solvation. That is ions are surrounded by layers of water. This is because the geometrical water molecule produces an polarity on the ends of molecules. This results in a lot of anamolous properties of water.
Also I think your experiment with the box here doesn't include a cooled down air which has more condensed water. I'm assuming there is a certain amount of condensation happening on the metal rings which would definitely explain how the system would work. Your experiment doesn't have any water and straight up ionizes air, which obviously produces ozone
The humidity in that area is always above 70%.
I think the key is to let water condenser on the metal ring or the needle. I have observed some coating on some of the ion units, I don’t know if that is sped up condensation. Can you try with some tiny amount of water in the terminals?
I wish all boards were labeled so nicely...
Maybe the sensing circuit is keeping an eye on the output to let you know when to change the module?
Possibly turning on the LED to the right of the ON switch when they need replacing.
The most important circuit there, Clive always gives them the benefit of the doubt but we all know the cynical money grabbing corpoculture creating consumables from thin air, literally this time
i *think* since you mentioned their claims of less ozone being produced, the rings are there to neutralize the ions again, essentially just having a small bubble of plasma over the needle that the air is supposed to just flow through and any dirt in it be murderized by the ions (and then probably attracted to the needles too) right there, instead of it actually releasing the ions into the exhaust where they would make e.g. way too much ozone.
technically their "water cluster" idea works out since water as a dipole would be attracted to the ions, but i doubt that those ions would do much to the cleaning or ozone production anymore, and it seems more like that's what the rings are for. the water would just literally dissolve the iron and shield it from any dirt to interact with.
22:10 correct me if i'm wrong but "influenza virus ... culture it on a petri dish"? that doesn't sound like a thing you do to vira, more like bacteria or fungi?
It does indeed. I did a double take when hearing culture virus on petri dish. Not sure how you would test effectiveness in neutralizing influenza really.
You can have viral cultures in a petri dish, although I think it's more common to do it in flat flasks/bottles because it's a liquid. Essentially, you have an animal/human cell culture in a liquid and then you infect it with a virus so it replicates in the cells. So I believe you can expose the culture to the virus to see if it was neutralized or not. But it is definitely different than the agar plates used for bacteria or fungi which is what most people think when they hear growing something in a petri dish.
If the ions are neutralized, then how do you explain the charge seen on the volt meter about an inch in front of the needle?
I think the rings are meant to increase the local field strength, like the accelerating anode in an electron gun. It increases the electron emission and speed. The faster they go the more likely they are to cause electron impact ionization of water, which would cause water molecules to break up like they promise.
Power supply is across the top, the right hand side is just a filter comprising of X2 capacitors and common mode choke to reduce conducted noise from the switcher. Nice to see schematics on the silkscreen. I though only I did things like that for ease of servicing.
29:04 would be cool to have a look at what that charge collector module puts out on a scope ❤️
Even if it makes the magic grapes, what is the effective range of these grapes? A 10 centimeter radius around the output of the unit?
It's a differential ion generator.
And yes, O3 as well as nitric oxide is a by product, thanks to the corona discharge off the needle.
Yes, and plasmacluster eliminate static electricity in the room and make particulate matters in the air clumps together so it can be filtered easily with it's HEPA filter
The bit that kinda convinced me was the negative and positive on the meter. Op amp is interesting though, it sort of adds credence to their claim in so far as feedback, I guess it indicates when maintenance required?
the markings on the back of this PCB look like they really wanted you to take it apart and look at all their nice engineering
That is a very nice well made Circuit board
It is. It's very neat.
@@bigclivedotcom I agree very neet and intriguing
I was hoping you would take a look at one of these, good to see it's not complete snake oil but it would be interesting to see if it has a measurable effect on air quality.
I have a Mitsubishi dehumidifier which has a "silver ion" filter and I'm not entirely sure what that does either - it seems to be some sort of green fabric filter (after coarse plastic pre-filter) that goes grey after time, but can be cleaned a few times by soaking in water. There doesn't seem to be any electrical aspect to this filter. It can operate in "air purifier" mode (no dehumidifying) and at least the pre-filter collects a lot of dust.
Silver is purported to be naturally antibacterial.
I have a larger version of this that has a much bigger squirrel cage blower that can move more air yet moves at a lower speed because of the size of the blower - which makes it whisper quiet on all but the highest speed. I love it. I hate all the new air cleaners and room humidifiers that have small, noisy high speed fans with blades.
What's the best way to remove dust from the air?
I have chronic fatigue and I'm not prepared to use my limited energy on dusting, so I'm looking for a solution to my increasingly dusty flat.
Me too. Also asthmatic. And allergic to dust. Never dust, suck. Use vacuum cleaner wherever and whenever I can.
A fan with one of these ion thingies and a hepa filter should help you both
The alternating drive to the four modules reminded me of the venerable Wimshurst machine with it's alternating brush electrodes for some reason. Maybe there's some relationship there.
"Refreshingly retro, very retro." Sharp products in a nutshell.
I lived in Japan for a few years and these Sharp 'Plasma Cluster' air filters were everywhere in most offices, shops etc near a corner whirring away. For a while they were marketed in the UK so I have one for a quite large room, its about the size of a regular home laser printer.
In Japan in Tokyo the summers are very hot and very humid indeed, if you leave a plate of food out it will very obviously go off (from the smell) in as fast as an hour without one of these going.
They do have a air detector built in that steps up the fan speed if an odour is detected.
The science of the charged particles clustering around dust microparticles, pollen, bacteria etc and decomposing or causing them to fall down to the floor is Sharps marketing theory. It may just be ozone or there is there more to it but certainly they work for cleaning the air in offices etc. Have to wonder at the minimal covid problem in Japan is due to firstly to their habit of wearing face coverings and whether these commonplace Sharp devices played a role too.
When I first came across the plasmacluster name it was in reference to their use in hospitals.
They're powered at seperate times because one is the positive and the other is the negative ions. If you run them at the same time, the ions will recombine quickly and not be spread in a room.
The way to test this would be to take a sheet of plastic, rub it with a cloth, which will give it a static charge, throw some dust or statically attracted particles onto the plastic, and then when you point the ionizer at it, it should dissipate the static charge in the dust and make it detach. That's how these are supposed to work, they get rid of static, causing dust and tiny particles to fall to the ground. They're also used for static removal in industrial equipment.
It turns out that they emit both positive and negative simultaneously.
I bought this guys big brother recently, mostly because it has a big HEPA filter. I think the HEPA filter does most of the work, but it wasn't more expensive than any other filter /humidifier I could find so I figured why not. My girlfriend has a pretty bad dust allergy and this thing has contributed a lot to her night's rest. I think despite the "plasmacluster" more than because of though.
Yes!
That last circuit board you showed us looks kinda like a voltage to current converter. Where does its output go, the microcontroller (through some kind of buffering probably)? What kind of input does that expect to see- digital/analog?
I'm thinking the whole unit's design purpose is to put out equal numbers of positive and negative ions, and that last circuit detects an overabundance of one or the other which would indicate that one or more modules is faulty.
The output on Page 29:00 tracks the plate emf limited by rail potentials. The guard trace around the plate tracks the plate emf by a delay for stability purpose. The pull up resistor value was chosen to delivers a bias current just enough to keep the output within rails within analog range.
Thanks Clive for splitting so many thing so we can se if it's worth the money
An ambient ozone generator, known in the state of Cancer to cause california ;)
Really???
@@WowIndescribable No, ozone does not cause cancer. According to the California Air Resources Board, it also doesn't do anything useful in concentrations that are considered safe - if there is enough ozone to significantly damage bacteria and fungi and remove smells, there is enough ozone to also damage your lungs (my interpretation of CARB's page on ozone generators).
@@daanwilmer lmfao. Did you not actually read the comment!? Hilarious!
Stay out of California, everything causes cancer there!
@@SGcomputing
Absolutely - I know from personal inexperience. 🙃🙃
The lawyers must have come up with Proposition 65, because that's all it's good for: a warning.
A side question that I never took the effort to ask: the two in-circuit resistors: would that be a use for a four-terminal setup in addition to the usual low-impedance measurement?
The rings are connected, so the positive goes to the negative ion side, is that really going to have as big as an affect as it could...
The opamp circuit seems to be a guard ring? They are used to shield a signal with a low impedance version of the same signal. It prevents leakage. Very odd.
Very interesting it has positive and negative discharge
Why does that module require changing after some time? Which part of the circuitry goes bad? Also what does the reset button in the back do? Resetting values/calibration stored in the MC memory perhaps?
It's very interesting to compare this to Sharp's original patent. The original Plasmacluster was a glass tube with electrodes embedded around. Current was applied across the glass tube ionizing the gas inside, similar to light bulbs, thus they named the product a "plasma" ionizer. The product they actually produced from that patent is basically just two regular ionizers that are nothing special or unique.
I Like the nod to thunderf00t
The quick-and-dirty test to monitor for ozone is a rubber band. Natural latex rubber reacts quickly with ozone. It would be straightforward to put the device into a chamber like a large plastic tub along with some rubber bands, wrapped around a cylinder, and see how fast they decompose relative to a control set of rubber bands left in open air. Then run the device in a small room with a closed door, see if the rubber bands decompose any more slowly than in a small chamber. Again, use a control set of rubber bands in a room away from the generator.
In this fashion, one could determine if the device seems to regulate its output based on the ambient level of ozone, or if it just cranks it out at a constant rate.
Yeah it does degrade rubber quickly,
I'm sure that's why BMW puts them in cars, it's not to assist your health, it's to assist their profits when the interior falls apart after about 5 years
Awesome vid, more investigation please, not like a big brand to make such wild claims, would love to know more
Back when I owned a 2008 Toyota, it advertised that it had a "Plasmacluster" built into the HVAC system. I wonder if it is a Sharp module like this.
Very likely, especially if it showed the same grape logo.
two paws up again. as alllways the Big Bearded one provides another great video to watch
shoenice reference?
"lot number Fall 2017..." Things that deal with internal voltage effects are better left unchanged when they work fine.
What goes wrong with the plasma cluster module with usage ?
I have been using a sharp HEPA filter with plasmacluster built in (along with a pollution sensor) for a few years now and it seems the module is not designed to be replaced (FPA80UW). I have heard it buzz like once a second for a few minutes then it just stops. According to the manual, sometimes it happens, sometimes it doesn't (only if it has been unplugged recently in my case)
I have also seen the plasmacluster ionizers compared to ESD ion generators or "balanced ion generators". Dunno if this sheds any light on it at all.
@Wellivea1 if you can see the needles then you should be able to clean them with a soft brush (every 6 months or so) and the needles could possibly be re-sharpened (every year or 2)
Probably your most useful piece of work so far. Pete on the Isle of Wight. LOL
Sharps seem to do well even in small sizes, but I guess it depends on the model
Wow, Johnny 5 lives again in an air cleaner.
"Johnny 5 says "Your Mother was a snow plower," LOL
We had a "portable" air conditioning unit with the Plasma cluster thing built in. It worked great until the condensate pump died last year.