DIY Desktop Fume Fan - The Learning Circuit

Solder fumes can be harmful to your health. Luckily, Karen has a solution. Build a desktop fan that keeps solder fumes away. You can salvage any old fan, as long as it’s DC, for this to work. To build this circuit, you’ll also need a nine volt battery or a twelve volt power supply, a power switch, an LED, and a resistor. You’ll need the resistor to power the LED, which means you’ll need to know the resistance value. Karen goes over calculating the resistance value to use either the 9 volt or the 12 volt power supply. Visit The Learning Circuit: bit.ly/2vqYYnn
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To build this circuit, you’ll also need a nine volt battery or a twelve volt power supply, a power switch, an LED, and a resistor. You’ll need the resistor to power the LED, which means you’ll need to know the resistance value. Karen goes over calculating the resistance value to use either the 9 volt or the 12 volt power supply.
To build this circuit, you’ll also need a nine volt battery or a twelve volt power supply, a power switch, an LED, and a resistor. You’ll need the resistor to power the LED, which means you’ll need to know the resistance value. Karen goes over calculating the resistance value to use either the 9 volt or the 12 volt power supply.
The resistor will go in line with the LED. Since this fan is rated for a voltage equal to or higher than the supply voltage, I don’t need to add any more resistance. I also want to be able to control the speed of my fan. This would normally be done using a 555 timer or another chip using PWM. To keep the circuit simple, we’re going to use just a potentiometer instead. It’s not the most efficient way to build this circuit, but it works. Potentiometers are variable resistors. If put in line between the battery and the fan, by adjusting the resistance, we also adjust the amount of voltage supplied to the fan, making it go slower or faster. If we put the LED indicator in series with the motor and potentiometer, it would also be supplied a varying voltage, which would cause it to burn out. We don’t want that, so here’s what we’re going to do.We’ll use a DPDT switch which will put the fan and the LED in parallel. The switch will be supplied the 9 or 12V on both poles. The resistor and LED are in one circuit while the potentiometer and motor are in another, both placed after the switch. This way, when the switch is turned on, both circuits are supplied the 9 or 12V.

[@klappstuhl4370]

Is it just me, or are flux fumes *always* homing in on the face?

[@jaybrewster2475]

Nah its not just you.

[@NERO-ez1mn]

just don't breathe

[@joshuainder2241]

Believe it or not research has been conducted and written to find out why 😂 It was concluded that the positioning of our arms cause this extremely annoying thing

[@TefCom12]

The right eye, always in the right eye.

[@wagnerthomas6780]

Because it's alive and wants to get inside you.

[@uwezimmermann5427]

nice project, but some comments: a) there are no toxic fumes from the solder metal itself at the temperatures used during soldering. b) LEDs are not "rated for voltage" - they have a certain, varying voltage drop at a certain current passing through. It is therefore we use resistors: to limit the current. c) you can safely use the same resistor (I would have chosen 470 ohm or even 1 kohm) for both power supplies. Doing the calculation backwards shows you that assuming 2 V drop over the LED and 470 ohm will give you 21 mA for a 12 V supply and 15 mA for a 9 V supply - you will probably not even be able to tell the brightness difference by your eye. d) yes, speed regulation with a small carbon track potentiometer is not a good idea. ...and finally I would probably mounted the filter mat before the fan to keep the blades free from condensing flux

[@tseckwr3783]

"regrettable acting" is always appreciated....

[@felixconf]

This was the best electronics tutorial I’ve ever seen. Thank you.

[@oscarmarfori613]

Bought mine in Aliexpress complete with stand a shroud and a filter and it’s really cheap saved me all the trouble of assemblies

[@craigs7181]

Excellent tutorial! Thank you 😊

[@tomtenberge]

You can just use a 1 pole switch, and tap it off between the switch and the pot, furthermore, i would have chosen to panelmount the switch, pot and led. The led will also light with 330 ohm, abeit a little less bright.

[@xFuaZe]

Meh just hotglue the switch & LED (or get one of those LED integrated switches off ebay) to the side, good enough :p

[@jonmoore1614]

This was really educational! I loved it! Maybe you can get Element14 to send you a parts box so you dont have to hack it together

[@ccedraro3878]

What a great idea, your videos are the best!

[@Alan_AB]

I've been soldering components for nearly 50 yrs. Whenever I make a solder joint I always blow gently on it while I'm applying the solder so that the fumes disperse away while I'm working. (Notice I used the word "gently". I do not blow so hard that it would affect the temperature of the work. Just enough to disperse the fumes).

[@northwestrepair]

Killer thumbnail

[@narwhalking2788]

I love the extra explanation for newbies. many videos sseem really fast and I haven't done electronics. This helps so I do it right fro the long run of a project I want to do.

[@shaunasilver9545]

if i use silver or gold solder paste for jewelry i would be using a tiny bit but i do notice a small amount of smoke, would an open window or regular fan work for ventilation since i am working in my kitchen?

[@SwapPartLLC]

I made mine out of an old broken electric heater. it had a 115v fan in it so it could plug right into the wall with no adapter. I cut it down and reshaped it so it's about 6" wide by maybe 8" tall and about 4" front to back. I had a lighted on/off switch i'd took out of something else, so I used that. Charcoal filter was for an range hood, and that's the only part I spent money on. Works great.

[@lukasperuzovic1429]

You are awesome Karen.

[@codewizstw]

great video. perfect pacing. Educational and entertaining. I watched this a couple days ago, but I felt compelled to come back and leave kudos

[@WallStreet749]

I love the way you show all the steps of what you do. What a cool Lady! I learned something :)

[@eduugr]

Awesome! This will be my first project. I'll try to do it with a PWM. THANKS !!!!

[@BarefootBushcraft]

Like 539 :) Yet another awesome video! I love the humour! I'll be making one of these for sure. I've pretty much got all the components lying around from old salvage jobs :)

[@aiyubthanksforexplanationc4046]

Extremely explaination I like your teaching I want to learn basic components from you

[@philtobin9510]

A handy little fan for removing flux smoke from the work area....Nice, but....There's always a but. The foam "filter " is just defusing the fumes and not filtering them, you may want to look at an activated carbon filter for that. As regards to toxicity, if you're soldering every day then maybe look into wearing latex gloves so you're not in contact with the solder wire, if you choose to use leaded solder. (Filter wise, I have found a 4" hydroponic carbon filter works perfect and you can find them for around £25. Yes they are large and may seem OTT but they will last a lifetime with a suitable RPM fan. Keep on with the cool videos.

[@briantamburelli7573]

I was looking at these fume extractors on Amazon but after watching this, maybe I'll make my own . I don't have a fan but, I would even consider ordering all the parts just to make it for fun.😊

[@MAYERMAKES]

that was also one of my first projects! so much cough cough memories...

[@HIEPPIEFUSARO]

Diy soldering station? or a foldable soldering setup or something to make it easy to wanting to make electronic projects.

[@nickayivor8432]

Thanks 👍

[@ghulamdastgeer8439]

Good job very nice continue this work

[@reasonablebeing5392]

Awesome video. Adding a charcoal filter (like from a fish filter) in place of the foam filter helps to absorb the smells.

[@lukasperuzovic1429]

That was a carbon filter she taped to the fan.

[@robertnussberger2028]

will more ohms equal less voltage to the led? Or does it need less ohms to lower the led voltage. I still don't understand ohms. I just thought one 1 volt would be -1 ohm, and -1 volt would equal 1 ohm. I would like to try this project because things like resisters and leds are cheap online.

[@mhlevy]

Was it something that I missed, or was the schematic incorrect, where it looks like the connections were between vR pins 1 and 3, with pin 2 not connected? Wouldn't that have turned the pot into a static resistor, rather than being variable?

[@brandishwar]

In this instance, you'd likely want to actually use a larger fan that pulls a lot of air at a good static pressure -- i.e. not an 80mm computer fan. I have something like this at home that uses two 120mm Corsair SP120 fans. Ideally you'd probably want to use a 180mm or 200mm case fan - or two - to really move the air. Only issue is finding filter material that large in one sheet.

[@kylek29]

brandishwar Agreed. I built one that uses a single 120mm*40mm server fan. Can move a lot of air, so I don't have to shroud it.

[@TortureBot]

Buy a Walmart Lasko box fan and tape a cold air return filter to it for about $15 total and have tons of fume-sucking power for minimal time/$.

[@MrMega200]

You just have to find a good source of carbon air filters and many hepa approved air purifiers have them, so it is probably be better for your health to make a filter box that your filtering material goes into(carbon sheet filter for smells and HEPA approved filter material for trapping flux) that you mount to the fan with a shroud to make sure all fume smoke go into the filter box. If you want to use a small fan then the Vantec Tornado is the way to go, just make sure you use a fan control circuit or a potentiometer to keep it undervolted or it will move on it's own under the air pressure.

[@leisergeist]

I bet one of those beefy 2U server fans would be great for this

[@gwbenites]

The carbon filter is only to remove odor from the fumes, but the actual harmful particles from the lead and flux fumes have to be filtered through a HEPA filter!

[@hannescamitz8575]

Seriously I like the scent of soldering, I know it's not healthy and I'm looking into building my own fan.

[@firebird8600]

Great acting, Karen!!

[@pegroj]

Nice content

[@oskar20086]

Thanks, and Let's do it!!!

[@rrcczz]

I'll be your fan.😀

[@PhattyMo]

I'd stick a transistor in between the fan and supply,and use the pot connected to the base of the transistor,to control it. Might be less likely to fry the pot that way.

[@NaoPb]

I love this video. Thanks Karen! But where do you get those push pins to install the cover on the fan? I have a few from computers I've taken apart, but I'd really like to have some more. Since they're a quick way to install a fan without having to tap the screws into the fan.

[@maker_karen1785]

It was already on the fan I used. Must have been salvaged with the fan when it was pulled from the PC tower. So basically, "Sorry, your push pins are in another tower."

[@NaoPb]

Even though you couldn't really help me, your answer did make me smile. You're one of the reasons I want to start soldering again.

[@KaroKoenich]

The regrettable acting is still there. Awesome!

[@BuckWezr]

I love big stitches and I cannot lie lol

[@HS-eq3gk]

nice video

[@Ksreddy440]

mam... please explain about LINE FILTER , and EMI & EMF

[@NERO-ez1mn]

wait wait where did u get the 0.02 amps

[@shrutimali5561]

Is there any difference if we use 555 timer?

[@MrCardeso]

Thanks, Karen!

[@alfredoghost2306]

What ohm range was that potentiometer? I've learned in trying to build this that a 5k potentiometer is not usable. (I should've done the math first but y'know). With a 5k it basically goes from off to full blast just right at the edge of the full swing. Rip

[@NERO-ez1mn]

where do you get the 0.2amps to be divided by the 7 volts? please clarify

[@kacperfilipek8461]

Probably a bit too late, but diodes have a tendency to "consume" too much current if you don't limit it. The voltage on the diode is about 2V, and the rest goes around the resistor. The current at any point in the circuit is the same so the current running through a resistor is the same current running through a diode. Most of the diodes burn out when the current is above 0.02A, so that's the limit you have to put to the diode.

[@NERO-ez1mn]

@@kacperfilipek8461 so what does it mean? 0.02A is the the standard amp? for the limit? tnx for the reply. iwas planning to start my electronics journey on this day & i think buuilding an extractor is the best 1

[@JPKB36]

more filters, maybe with a workspace in a transparent case, should be nice

[@TBSxDRUMS]

Might be a silly question, but can I just use a regular battery-powered or wall-outlet-powered fan and place a filter on it? Rather than assembling all these parts. I feel like the answer is a self-explanatory "yes," but I just want to be sure since I'm new to electronics and soldering. If I need a fume fan to avoid solder smoke, I don't necessarily want to solder and breathe in the fumes in order to create the fan lol. Awesome video, and a cool project to practice skills. Entertaining presentation as well!

[@Retroaria]

Nice Idea. I will make one using rechargeable cell phone battery.

[@TheDc1984dc]

Damn. Got that dank on hand?

[@devdeque7846]

Karen hot boxin' it up in the thumbnail :D

[@hlavaatch]

What the Heck, dual pole switch? Why?

[@scotttovey]

She chose the dual pole switch to make it easier to utilize the two different voltage sources. The 9 volt requires a smaller resister than the 12 volt to power the LED without burning it out. Yes, you could utilize a voltage regulated supply that outputs the same voltage regardless of it's input. But bear in mind that Karen is teaching basic electronics in this series and going to the more advanced circuitry limits the knowledge being disseminated and the skill building that is needed at this level.

[@MaxWattage]

Erm no Scott. To be fair, she probably just used whatever switch she had to hand, but if you check the schematic, you will see that a SPST switch would have done exactly the same job. The PSU is wired into the common terminal on the switch, and so both outputs of the double-pole switch are ALWAYS at the same voltage, so the second pole is entirely redundant.

[@arnab_blue]

@@MaxWattage WTH... I thought the schematic is wrong... But her PCB soldering also wrong... so confusing... So the battery is actually useless...!!

[@TheMixmastamike1000]

Where did you get.02 amps for the ohms law equation?

[@NiHaoMike64]

Rating of the LED. Some LEDs are actually too bright at that current, so use a larger resistor.

[@TheMixmastamike1000]

NiHaoMike sooooo in the data sheet?

[@CreepebrineMC]

Lol I NEVER use such a fan. Instead I open the window next to my desk.

[@YugoZex]

It's nice and entertaining but I think after putting air filter you should increase fan speed not decrease it with pot totally not needed and you are probably not going to solder so close to the fan. So more speed for larger distance and some direction like hose is better for sucking fumes. This is nice for education that are starting to learn soldering. Nice job but need part 2 for improving this idea...

[@xFuaZe]

I'm still wondering why a DPDT switch is any different from a SPST with both parallel (variable resistor & fan) and (LED & resistor)? The argument for DPDT was because they "shouldn't be put in series", but why not put them in parallel after a regular switch? When you turn the 'lever', but you have both inputs connected to the same line, both outputs are also effectively the same line?

[@scotttovey]

DPDT is an on off on switch. It is affectively two switches in one. So while both sides share the center tap which should be wired to ground, their other pins are wired to the two different power sources, one being 9 volts the other being 12 volts. While you could attach both power sources to the center tap and then utilize the separate throws that then point to the different sized resisters, there is the possibility of moving the switch to the 9 volt circuit when the 12 volt source is connected. This design makes that possibility nearly impossible. This design also allows the 9 volt battery to remain connected when the 12 volt source is connected making it a battery backup.

[@xFuaZe]

Since the poles are one one side both connected, it's no different from a regular switch. The voltage before the rest of the circuit is the same (either both grounded or both 12v), the resistor reduces flow through one of the parrallel tracks, but the switch doesn't have a reverse-protection diode and doesn't really make sense imho.

[@michael.a.covington]

The current through an LED does not have to be exact -- anywhere from 5 mA to 20 mA will generally do fine. So I don't think the resistor will need to be changed for a different color of LED.

[@supersaiyangoku3580]

You can buy a PWM module on Ebay for cheap. Its prebuilt

[@josephciaravino4115]

She’s awesome!😂

[@jayemerd1984]

Project Idea: How about a controller made in the shape of, or made with, a fidget Cube. wired or wireless, You decide.

[@salwaaltahir988]

I had fun :)

[@Samuel-km5yf]

A mechanical switch??? This fan needs voice activation!

[@hlavaatch]

More like cough activated ;)

[@OmairArif]

I did that with a $4 Sonoff SV and a old 200mm fan I had laying around to make a desk fan.

[@supersaiyangoku3580]

Because you people are lazy!

[@certified-forklifter]

alexa, turn on that fan!

[@diegor4966]

Also needs an enclosure I am using a 3D printed fume extractor enclosure that I found on thingiverse works really well and looks nice!

[@AirborneSurfer]

Next episode: "Alexa, turn on fan."

[@TortureBot]

(Alexa immediately turns on a fan and starts pummeling the supporter of Amazon's popular virtual assistant with derogatory remarks.)

[@cryo_life]

Might as well solder in the bathroom. Just turn the fan on without creating a new fan! It's free lol

[@user-pz8fw1ik4f]

I'm your fan

[@murrrr8288]

Watching this 4th time now. Little progress every time :D

[@twycross3]

I like big switches and I can not lie.

[@JMNTN]

I just rely on my nostrils filtering the air

[@mediocreman6323]

You think _you_ are tough? Well, _I_ … live on boiling coffee and raw onions only, walk 20 miles each day to and from work uphill both ways - while dragging a grown tiger with aggression disorder by its tail - when I am at work I forge iron bars wit my bare hands, and I recently moved in with my mother in law. Top that 😄

[@Prosth3tiks]

Just make sure you dont trim your nose hair.

[@jameswaichungo7306]

Nice but bothers me that approx 30watts of power will be lost at 12volts,great video btw

[@oswaldjh]

It would seem that Karen is a graduate of the Ben Heck School of Acting. She has his mannerisms down pat.

[@MightySquirrel724]

If you get a plastic container, cut a hole, hot glue the fan in place, and fill the container with air filters... no fumes at all will go into the air.

[@compelledtohurt]

I guess you let that magic smoke out

[@nasko8605]

Make this with bigger Fan - it's more efficient for this porpoise :)

[@TortureBot]

You're a porpoise?

[@abhishekrajbhar1666]

i Like

[@ricardoricardo3232]

Are the fumes bad for you ?

[@element14presents]

They're at least an irritant, best not to inhale them.

[@MathieuBurgerhout]

499 ohm? That's oddly specific... E1 range?

[@highlander1387]

nice build! ;-) :-)

[@snipersquad100]

You look like Fran with those glasses on.

[@russellesimonetta3835]

Nice simple circuit! You lost me anywa.y

[@helldog3105]

Woah! If your solder is smoking that bad, something has seriously gone wrong!!!!

[@EclipticFactions]

flux core solder makes a lot of smoke.

[@MrMonomonster]

Actually you can use a SPST switch if you put it on the low side. I think it's OK to have tutorials like this, however I have a feeling that other followers of the original program, like myself, would prefer to see more advanced designs and builds. Making a portable console that could play Gameboy and GameGear cartridges and stuff like that! :)

[@jorgeszabo1659]

Ben never used a fume extractor lol

[@megan_alnico]

And he used to use his teeth to strip wires... No one can say safety was his top priority.

[@SaiyedR]

😂😂u act funny 👍👍

[@neobikes]

i am so stoned now....

[@jakedjo]

I still don't understand why she subtracted the two voltages in her LED resistor calculation...

[@maker_karen1785]

I go into further detail about Ohm's Law in this video, kzbin.info/www/bejne/oYLSfayVqthogJY.

[@xFuaZe]

I'm thinking: The resistor is used to limit the power going through the LED (P=u*i), so the excess power (the difference in voltage and the maximal current) should be limited? But in this case the maximal power of the LED should match the power (after the resistor), I'm just not quite sure if it will actually regulate the voltage/current (afaik still 9V but just 4x lower current?) Though I'm thinking that the LED has a set current and thus voltage is limited (as in a voltage divider).

[@jakedjo]

That video was no help at all. The reason I'm confused: 12v / 500ohm = ~0.024A . The resistor only affects the voltage, not the current. Also, wouldn't the Potentiometer in parallel affect the current of through the LED?

[@nasko8605]

Nope - this pot is in another part (or circle) of a circuit, witch is closed thought the motor (Kirhof's lows ) . The current is determined by a choose of led , not by the resistor. You are right - the resistor will limit the voltage. Overvoltage on led is not recomended too, like overcurrnet. (See the datasheet of any led). But Caren is in error with determination of resistor - always choose higher stadnarT resistance than calculated !

[@Unordung]

If you look at the datasheet for an led it will have a value called VF or forward voltage. This is the voltage which is needed for the diode to conduct. This varies between different colors etc. To calculate the resistor you need you simply use Ohms law which is V=IR, we want R so it transposes too R=V/I, V= the supply voltage (VCC) - the Forward voltage of the diode (VF) divided by the current you want in this case 20mA. Therefore R = 12v - 2v / .020 == 500ohms

[@michaelhofmann5091]

why not talk about Current when Talking about Led's?

[@vasili1207]

The fumes are still in the room

[@javilarg]

It will never be the same without Ben. 😔

[@surajlal]

wrong station dude this is element14 not the benheckshow ffs

[@ThomasFranksomt]

dpst? you have to be kidding!

[@lukasperuzovic1429]

In my parts bin all I have are DPDT switches, and it use them even if a single pole single throw is needed

[@ThomasFranksomt]

Lukas Peruzovic , yes, I would too, but you wouldn't use both poles when one will do the job!

[@DaveCurran]

Sorry, but you should perhaps run these past someone with more electronics experience first. The potentiometer is unlikely to be rated to handle the power of the fan, and the schematic is drawn incorrectly with the wiper not connected and only the fixed resistance of the track in circuit. Also the double pole switch is unnecessary as it makes no difference the way it is connected. Rough calculations, with the pot at 10%, looks to be marked 1K, so 100 ohms. The fan was rated for 150mA, it's difficult to calculate how much current it will draw, as it depends on the design of the fan, so say it's half that to be generous, 75mA. P=I^2 R, so 560mW. Most potentiometers of the style shown would rated at 125mW max, so it's being run at more that 4 times it's rated power, and probably won't last long depending on where it's set. A wirewound pot could be used, but they are more expensive / more difficult to get hold. Maybe a fast/slow switch with a suitably rated power resistor bypassed for 'fast mode' would be better, assuming a PWM controller or a more complex transistor driven circuit is not an option.

[@surajlal]

you should make your vid eh?

[@ciri151]

420 blaze it

[@alienozi]

regretable acting? well ith still here

[@tookitogo]

This circuit is a hot mess. (Literally hot, in the case of that poor potentiometer!)

[@DacooX360X]

Love this! Advising people to use a 200mW rated Pot (likely) to control a approx 2W load. A very “hot” mess indeed...

[@neosandi6]

funny

[@mujahidtheengineer]

Honest #psa

[@Grizzlybrar]

I swallowed a soldering machine

[@middleway1885]

Boop

[@ItsDextrin]

Tin your soldering iron

[@johnd942]

JUST DO IT! FAR TOO MUCH 'GAS-BAGGING' AT A RATE KNOTS! Where's the fire!?

[@TV3MASTER]

hmmm, ben would have explained what the white wire (fan speed wire) on the fan was used for. even tho they arent using it, it's still good to tell what it does, so people who don't know learn it, like they do it now just makes everyone dumber...