Build an Ioniser in Under $10(amaldev.blog) |
Build an Ioniser in Under $10(amaldev.blog) |
https://en.wikipedia.org/wiki/Air_ioniser#Adverse_health_eff...
Personally I don't see the benefit over a HEPA filter on a standard electrical fan, or a commercial unit with a similar design. Yes, replacing filters is annoying/has a cost, but there's no health downsides to the design and it is effective at removing air particulate. Building one requires an off the shelf HEPA filter, an off the shelf fan, and a couple of rubber bands. It isn't "sexy" or technically sophisticated, but it works. Want it improve effectiveness? Increase the surface area/make it bigger/increase the airflow.
Let's also consider what both devices (when working correctly) do. An Ioniser gives particulate a charge causing it to be attracted to and stick on surfaces. A HEPA traps particulate within a filter membrane. Or to phase that differently an Ioniser causes the particulate to dust onto every surface within range, causing dirt buildup/stains, dust blooms when disturbs, and people may still contact the air contaminants (since they still exist, now on surface rather than in the air). HEPA allows you to simply remove the particulate from the environment, Ionisers just move it from one location (air) to another (surface).
(time-linking since the ioniser part was sortof hidden within a video debunking himalayan salt lamps)
They then proceed to build a device that will, if anything, exacerbate this exact issue.
If the dust is airborne, it will naturally spread everywhere before it eventually settles. Making the dust settle early minimizes spread.
I don’t find that at all. The dust that sticks to surfaces in my apartment can’t be moved even by forceful blowing on it. It has to be wiped away.
Also, I notice that when I brush stuck-on dust off a surface (e.g. my coffee table), it’s still ionized—so it just either gets pulled back to the sides of the table, or to the floor.
An ionizer doesn’t need maintenance, but that’s because it deposits all the gunk nearby. Eww.
Also lots of hand soldered MLCC caps are high potentials. They like to crack and explode if you do that. They need to be machine soldered really.
Edit: also the design doesn’t use proper voltage rated resistors on the output. I haven’t checked the other parts but it’s probably marginal. You’ll get home one day and find your house burned down.
You will be able to smell if you are producing ozone, which you don't want unless you like permanent lung damage. The smell is sharp. like around electric sparks. If you get that, the voltage is too high. Just leave off a few voltage stages.
Also, the health claims of ionizers are dubious. False claims about them (and ozone) bankrupted The Sharper Image
That's a good one, thanks!
However - DON'T DO IT. Many ionizers generate ozone which is unhealthy.
Also if the goal was merely to combat dust settling on the floor (rather that health), it will only make the problem worse.
Crop burn pics: https://www.theguardian.com/world/2019/nov/08/indian-farmers...
https://www.eurekalert.org/pub_releases/2019-08/imaw-atb0807... suggests there are better alternatives that will yield better returns for the farmers; but I gather some UK farmers want to return to burning as it - in their eyes - reduces weeds and provides ash for tilling in to the soil. It's not a simply equation though, eg https://www.researchgate.net/publication/230319729_The_effec....
Still a small cost ($0.52/yr in the US)
what about "manual" solder paste reflow ? I think I saw a few vids where people hinted at the fact that it's uneven heat and physical stress from handling that caused damage
Those needles connected to active make me uncomfortable, though there's a 10M resistor, I'd have an isolating transformer on the mains - not an engineer though.
Isolation transformer is not required if the enclosure is better. It also doesn’t help you if you stick yourself across it somewhere, only helping yourself with respect to ground. If you’re testing it or doing development with it I would use one. But I wouldn’t build it.
I used to hang around inside old valve radios when I was a kid. You learn respect for high voltages very quickly.
https://hackaday.com/2016/05/11/looking-mains-voltage-in-the...
The output resistor need to handle potential to ground so say 7kv across output to ground. Resistor is rated for 200V working voltage. Usually you use a chain of many smaller resistors here.
I haven’t reviewed the design entirely but the main problem is the enclosure and mains connection and the component choice. The mains connection should be clamped in the enclosure and either spade connections or screw terminals or ferrules. The enclosure should be double insulated. As mentioned a fuse would be a good idea as well.
Always design for worst case with these things.