Fixing a fart-extractor (with schematic)


108 Tsd. aufrufe5

    An inline toilet fan with timer that was sent in by Will (physicmad).
    In the UK we use toilet/bathroom fans that have a continuous and switched feed. When you turn on the light in the room the fan starts, and then continues to run for a fixed time after the light has been turned off again to purge any aromas or excessive humidity.
    The circuitry is usually very minimalist, using a current limiting resistor that is sometimes prone to cooking to the point that it can sometimes short out in some brands, with undesirable results.
    It's been pointed out that the resistor may double up as an anti-condensation heater to keep the enclosure dry.
    This unit has an intact resistor, but Will said the timing started getting shorter and shorter and the fan would sometimes struggle to start, even though it was free to spin.
    Can you guess what the fault was?
    The easiest fix for some of these is to remove the PCB and add a bit of terminal strip to run the fan off the switched feed. Just remember to leave the light on for a while after a bath or shower to remove the humid air.
    If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
    This also keeps the channel independent of DEfasts's advertising algorithms allowing it to be a bit more dangerous and naughty.

    Am Vor 10 Tage


    1. Apurva Bahadur

      Charging a 470 uF electrolytic capacitor from CMOS gate output? Is that a good thing to do?

      1. bigclivedotcom

        The internal MOSFET tends to have enough resistance to avoid problems.

    2. LegoTekFan486

      An interesting setup, but the problem with this is when the fan breaks and starts sounding like a cat being tortured, you have no way to turn the f*$%#ng thing off, thus your upstairs neighbor hates your guts because the god#@%$m light is also on a motion sensor so you can't walk into the bathroom without starting the stupid fan. You send the apartment people one maintenance request, but of course, it's been a few weeks and nothing has been done yet. So you duct tape over the motion sensor, but the apartment complex notices the sudden absence of noise complaints from your upstairs neighbor and sends maintenance to see what you did. They see the motion sensor taped over, and that ends up counting as "unauthorized electrical modifications" thus getting you evicted.

    3. Chris Scogin

      Well I put off watching this one because i was thinkin?? Fart extractor? Why would I want to extract them when they are so much more fun naturally.. but then

    4. Zune

      Where's the stripper? 😁

    5. Derek Reeves

      I like how Will put his name on his fart extractor. Like "Will's fart extractor"

    6. A Wilson

      16:36 With a Circuit Board that thin, the only real choice they had was: Do they cook the diodes, resistors and capacitors or do they cook the logic chip? Which set of components is more prone to heat related failure? Personally, I'd have made the Board at least 3 times wider that that one and split the one resistor into multiple High-Watt Resistors in Series across the top edge thus spreading the load out and ensuring each resistor generates less heat to avoid cooking the rest of the Circuit...

    7. A Wilson

      My first guess would actually be either a bad fan bearing or a bad motor winding... My second guess would then be a bad component in the control circuit... And I don't think this was designed as a Fart Extractor, I think it was intended as a bathroom fan to exhaust the hot, moist air from a shower... Extracting Farts would be an unintended side effect - or if it was an intended effect, it's unlikely any of the Designers would ever admit it to their Bosses... EDIT: It appears I should avoid a career as a Circuit Diagnostician... That's OK, I MUCH prefer a Career as a Circuit Blower-Upper...😈😈😈 😁😂🤣

    8. Trey Cook

      I must confess: I clicked because "fart".

      1. bigclivedotcom

        It's always worth doing.

    9. S. Kraus

      Like the Hopi tester. Looks like it is only available for GB/US outlets. Do you think the outlet could be changed to another (like Schuko)?

      1. S. Kraus

        Just found your video on that matter--- everything is crystal clear now :-)

    10. Jason Wilde

      12:37 'It's not Ideal". That's my line! I use that all the time! Do I own the term, no. But I use that phrase almost every day, for example. "How is the weather for painting outside today?" "It's not Ideal". I'm soo glad I found this channel!

    11. mrhockeyhead83

      I'm an electrical engineering student and I learn more from clive than any of my teachers

    12. Logan Mailandt

      oh man those 4xNOR chips bring me back to digital electronics class in high school. honestly, they probably did it that way just so they could get away with one logic chip on the board.

    13. Boeing 747-8

      I present to you, the Fart X-Tractor 2002!

    14. Christopher Dyrlich

      So.. If i get that right.. The Fan itself runs at 240 Volts AC Main Voltage? Because i'm thinking about using a more logical approach and let an Wemos D1 decided when to turn the Fan on or off so i have to scrap the whole Circuit and build my own one because it would'nt fit otherwise.

      1. bigclivedotcom

        It does run at 240V.

    15. Eric Davey

      Considering all the problems people have come up with using these things with noise and so on, I still prefer the better method, where possible, of just opening the window for a while.

    16. siraz shaikh

      That Scottish accent

    17. MrCalldean

      You can see the board is browned where it's being warmed up all the time.

    18. William Steele

      You'd think that the designer would have realized that the resistor could have been easily cooled by the big fan it's running!

    19. Iris

      Not sure if the one I have (it's meant for constant ventilation for the room I am in since it doesn't have a very good circulation otherwise) is supplied with this circuit, because I've had two and while looking similar, both of them suffered broken bearings (we found out after opening the first one they are not ball bearings, so that obviously does not help). Most common thing that starts to give them away when the bearings start to go is the thing making an awful screeching sound.

    20. Geoff Hilton

      The capacitor cooking resistor is built in obsolescence ie. it will fail after the 12 months warranty.

    21. Justin McCowan

      Here in the states we could use a fart-extractor with all the Taco Bells, Taco Tuesdays, things with beans, eggs, and all that jazz at every loo after all the things we eat!

    22. Blondie SL

      Funny title. I nickname my EX that. LOL But I digress.

    23. RSWingman71

      1:35 - This guy really knows his schmitt!

    24. pprecuero

      You should be a professor. I am a mere mortal who has interests in the whole electronics thing and I actually understood everything you said about the circuit. Oh, and keep in mind that my major is Advertising and Marketing!

    25. smeezekitty

      A 16 volt capacitor in this application is way too close for comfort.

    26. Против Глобал

      Clive, why not get a proper LCR meter? I have DER EE DE-5000. It has amazing specs for the price.

    27. Против Глобал

      16V capacitor for 15V. Very naughty. :I

    28. toxin liquid

      Instructions not clear , pluged in my anus to extract farts

    29. Gustaw Napiórkowski

      Wow, just a day after this video I noticed my vacuum cleaner struggling. I opened it up, it had a similar circuit. I changed the filtering capacitor and it now works like when it was new! Thank you for those videos they are awesome!!!

    30. neilw2O

      Stripping wires with the cutters? Holding it the way you do looks right, but try the cutters flipped over and see how much better it works, Explained to me years ago by an adept engineering acquaintance. Easier than desoldering braid: Stainless steel tapered spike. Melt, poke, done. Solder braid often makes the pad lift if PCB quality is low, as it usually is.

    31. Alex C

      Those M-Testers are brilliant. I wouldn't trust them for accurate, but it's impressive they can test so many different components AND VALUES using just a handful of digital IO pins. BTW it's some open source design that everyone rips off of, everyone has a different version with different component support

    32. Alex C

      0:45 - my guess is bad capacitors, one in the timing circuit and one connected to an AC motor. Very odd that they would fail at the exact same time, but maybe they're from the same batch. Let's see if that's right...

    33. BlackIce504

      ceramic resistor would have been better too, that is really bad stinky design, it might get rid of farts but you will smell baked PCB. what where they thinking indeed.

    34. Joe Billard

      That is the most complicated bathroom fan I have seen. why so much technology? Our bath room fans in the USA are simple. Just a motor and wire. Literally. Great Video!

    35. Emad Iskander

      Is the fan spinning in the right direction?

    36. thomasking55

      Good fix, bravo!

    37. Willopotomas

      You're pretty good at this sort of thing. Should maybe look to make a career out of it. hahah. (Check yer e-mails, bud. Sent you something you may be interested in)

    38. alun roberts

      Some I have seen have a idle time and run time so when the light is on it hangs on counts then runs so if some one just having a wee wee the fan don't run.

    39. Sherlock Ohms

      Nice repair, Clive👍 ...but this size of fan is useless, it couldn’t blow a candle out. I had to upgrade to 6” ducting & inline fans with 12” blades- supply & extract. If you ever went to the bathroom after my ex had been in there you’d know why I went to such trouble.

    40. hadi reg


    41. Adam Jones

      Fart extractor LMAO

    42. Damaged Provider Module

      So people fart into the fan or what?

      1. Damaged Provider Module

        @bigclivedotcom that's insane. I'd have to carry that thing everywhere I go and I'd probably break it by farting too much. Good luck with your flatulence fan.

      2. bigclivedotcom

        Yes. It attaches to the rear trouser port with a flexible pipe.

    43. deslomeslager

      Drill a small hole on 2 places, such that air is as well sucked through the box containing the pcb and the hot resistor.

    44. Matze_ Stuggitown

      Literally clive has 4 hands 🤗

    45. cull510ender

      Flux on solder wick? Going to try that! Thanks.

    46. David Reynolds

      Im not an expert on fart extracters butt that thing looks like it would hurt your arse! I didnt have the courage to watch the installation of the unitinto the...unit

      1. bigclivedotcom

        You have to use lots of lube and relax.

    47. muzikman2008

      I had visions of a decade worth of miscellaneous dried up fart powder blowing in your face when it came back to life lol :-) I'm sure a 555 timer would be more cost effective?... I have changed many fans over the years with failed control boards, they're just as you say cheap and designed to fail after a few years.

    48. Mitch

      Thanks Clive! Another great video!

    49. Paul Stubbs

      What an absolute crappy way of deriving a 15V rail from 220V, they should be shot

    50. James Bowie

      If the designer/manufacturer had actaually given a damn, they could have provided through flow ventilation of the power resistor via the fan itself.

      1. bigclivedotcom

        I think it's doubling up as an anti-condensation heater.

    51. James Bowie

      That's not a TRIAC, it's a gate turn-off thyristor. TRIACS can't be switched off via their gates.

      1. bigclivedotcom

        Definitely a triac. It can turn off at the zero crossing points of each cycle.

    52. James Bowie

      No farts were extracted during the making of this video.

    53. S H

      Great video - thanks for also checking the faulty cap with the component tester, just to go full-circle :)

    54. mark layton

      the postage costs of sending to you - then sending it back - is it cheaper to buy a new fan ?

      1. bigclivedotcom

        It's cheaper to watch a DEfasts video and then try fixing it yourself.

    55. GreameCheese

      Ah yes the fart fan, the most noble of fans.

    56. Latticewood Spobiance

      No need for such complexity for a vent fan. The use of electronic components is just asking for problems.

    57. lordfly911

      I hope you washed hands before and after.

      1. lordfly911

        @bigclivedotcom second hand fart. Hehe. Stay safe

      2. bigclivedotcom

        Yes. Although I did eat a sandwich while I was handling it.

    58. Shawn Frizzell

      ok caps and i would suspect the mechanical part first within the circuit for example the pot.

    59. Shawn Frizzell

      can i fit one of these to my trousers ?

      1. bigclivedotcom

        Yes. But make sure you put a finger guard on it.

    60. Graham Langley

      Has the hallmark of being designed by someone with little experience. Why is the one input of the gate after the timing cap connected to 0V? Why isn't the spare gate connected in parallel with the TRIAC gate driver to share the gate current? Why weren't the last two gates converted to a Schmitt with the addition of two resistors to give a better switching action?

    61. Paul McCoy

      I would have just opened it up and changed all of the capacitors without thinking of how it was making the circuit misbehave.

      1. Paul McCoy

        Yeah but it’s so elegant when you do it.

      2. bigclivedotcom

        Which would have worked.

    62. no last name no panic 666

      My toilet fan never worked so I took it down clean the dust out of it and even inside the pipe then I took the fan apart and it was burnt inside all the wires were cooked so I went to hardware shop and got a new metal toilet fan and I put it in my bathroom and it works like a dream

    63. Allan Copland

      Having always used CMOS on a 5V supply I've learned from this. Cheers Clive.

    64. fontik

      It's worst product in home industry, loud 🔊 and inefficient, we changed fans to big 12volt computer ones and it's even powerful, quiet and safer for bathroom with water, no risk of shock with 12 voltage ⚡ and low current. Ac to DC power adapter outside bathroom.

    65. Hal Ucigenia

      And I just replaced the fart-extractor in my bathroom the other week, if only I had known.... The circuit was quite a mess as it had had water leaking through the fan, and I had refurbished the fan previously so it was probably best to have replaced it anyway. Next time I get in the loft I will have to make a u bend in the conduit and a small hole and container for any condensation to flow out before hitting the fan.

    66. Brad ൠ

      ridiculously smart how he always knows exactly which part to replace first try 😂

    67. Steve Leahy

      What would happen if you used a ceramic capacitor instead

      1. bigclivedotcom

        These days a MLCC type capacitor could be used.

    68. smart hound

      Fixed, with Clive's coveted "Fart-B-Gone" warranty.

    69. Jim Pugh

      what about drilling a little hole in the fan surround to suck out some heat

    70. Ragnar8504

      Not sure how common they are in the UK but on the continent you can easily find external timers for fans. They work exactly like this one but they aren't internal to the fan. You'd typically fit them into a junction box somewhere near the light wiring so you've already got the permanent and switched live at hand and only run a 2-core to the fan.

    71. o

      Wait, you guys are using it in bathrooms (Crying in WIDE ARSEHOLE)

    72. mike hughes

      Fartastic jobie Clive, well done.

    73. Hunter

      Clive, you have a way with words. I’m really enjoying and learning from these videos. Who would have known whats inside all those electronics. You should do more MRE reviews because people really enjoy watching those. 👍⭐️

    74. TechyBen

      Hmmm. I wonder if this is happening to my fan. :(

    75. Mārtiņš Belte

      Hmm, this made me think about my home theatre amp. Its volume started to fluctuate as time went on but opening it it wasn't obvious if a capacitor is broken as they all looked fine. Anyone has knowledge on amp troubleshooting which component I should look at?

    76. exi

      I've rewired the fart extractor at my mothers to solely run on switched power because that particular bathroom was mainly used for washing hands and running that annoying fan for 5 minutes after you had the light on for 20s was neither very quiet nor energy efficient.

    77. AdjustableSquelch

      you can build every other logic gate from NORs and the Apollo Guidance Computer only had NOR chips inside

    78. Sidecar Bob

      The main purpose of a bathroom fan is to remove water vapour from showering or bathing so it doesn't cause the wood &c to rot. Extracting odours is a bonus side effect.

    79. Daniel Dulu

      Would replacing that resistor with a ceramic one help?

    80. Erin Ralston

      So this removes a fart from a room, or from the source?

    81. Ryan Olsen

      We must have much larger farts in the us. My fart fan is 3 times bigger than that, and rarely keeps the smell down.

    82. Martin Gannon

      Excellent training knowledge for all new greenhorns. Thanks Clive!!!

    83. Matthew Miller

      Hmm, makes me wonder if I should go over the brain in our oven a bit closer checking out the caps... sometimes it doesn't pull in the relay to turn in the heating...

    84. ableite

      Even though the fan didn't burn, i guess it still smells bad. Lol

    85. Fart

      Leave those farts alone.

    86. Stop asking for my real name!

      I had several pieces of gear where manufacturers have placed the Electrolytic caps in the power supply right next to the regulator heatsink. After the first device failed, I said this is gonna be a problem. Sure enough after the third and fourth units rolled into the shop, I did a field modification and moved all the caps as far away from the heatsinks as I could. The kicker was the designer could've put a stud on the metal case for the regulator and not needed a heatsink.

    87. russell zauner

      All this makes me think is that one room's fart extractor is another room's fart injector

    88. C S

      Mr. Clive, some feedback for you :} Since you use a phone for video _(apparently, based on the Tupper-Cam vid?)_, and since said phone also has Bluetooth.... why not get a BT Mic to clip on you, so that when you bend away from the bench while talking, we can continue to hear your ramblings! :D Sincerely, a new fan (but not a fart-extractor)

      1. C S

        @bigclivedotcom Yea, that makes sense. I imagine a lot of those cheaper ones probably don't sound that great... AND admittedly, when you *are* in range of the mic, it does sound very full bodied! If you do try the other one, hopefully it works better. Thanks for the reply and the content!

      2. bigclivedotcom

        I tried a BT mic in the past and it was very "compressed" sounding. I was recently offered one that claims to be better, though.

    89. Toobula

      Nicely done. I was betting on the timing cap. I bet the CMOS NAND gate design was because the chip is basically free, and the inputs to the gates (especially CMOS) are very low leakage so they won't help that timing cap down.

    90. Nathan Lucas

      Considering the price of some of these fans, it's crazy how cheaply built they are. Nothing about them suggests a quality product

    91. Michael Hagberg

      Everyone one else: "Don't do this at home, I'm a professional." Big Clive: "Don't do this at home. I'm an idiot." :)

    92. groove jet

      12:44??....When Clive says.." It gets hot in here! It's not ideal"..? I instantly clicked :comment"...Ha ha ha... But as I was pressing back on video, numerous times, to check a accurate time stamp? I realised.he was.on about pcb! 🤨😂😂 I was so Because I was dying to make.a.comment about his home being like the North

    93. beartastic

      "that's okay, it'll dry up and disappear" ... leaving a sticky mess:P

    94. Tony Mudd

      Helpful video - wish I'd found it a couple of years ago when I did the same fix! The timers on these cheap fans last < 2 years. Last time one went wrong, I replaced the internal timer with a mains relay and timer relay (£2ish each from Banggood) add a box, total about £10 - lasted 2 years so far. My circuit isn't completely correct that the timer starts when the light is first turned on and not when the light it turned off, so no "sitting down" for too long or the fan goes off!

    95. Screwdriver440

      I wonder how much poop there is smeared on the blades

    96. Firestarter

      My toiled seat turns on a fan that vacuums out toilet bowl air through an activated carbon filter when I sit on the toilet and for a minute after I leave. It works splendidly and is nearly silent. When I press the dryer button it spins reverse and blows warm air over my ass to dry it.

    97. amojak

      horribly inefficient as it draws power all the time. a smarter move would be to make the light switch charge up the 15V supply via the resistor and turn the triac on direct. then when the light turns off the 15V rail will drop slowly until the triac drops out. this would eliminate the need for quite a few components too.

      1. amojak

        @Jonathan Schneider you would do this via the supply as mentioned. it means there would be a short delay while the cap charges up form the light before the fan comes on which is probably desirable anyway, then a simple transistor could be use to produce the avalanche trigger to the triac or for the sake of cost just be the diode, R/C and zener to cap the volts to be safe for the triac gate and cap limits, this does not need to be 15V as no 4000 series. The use of the logic chip is redundant. I think Clive should do a build video for a simplified version of this circuit so we can see it in action.

      2. Jonathan Schneider

        Maybe but you'd still need something to feed the triac gate and I haven't quite thought of a nice way to do that

    98. amojak

      I guess you could be ultra modern and replace the resistor with a suitable sized cap to sort the heat issue.

    99. Grant M

      you keep your jobby fan to yourself, Clive

    100. gazzaka

      I thought you'd replace the recistor with dropper cap

      1. gazzaka

        @bigclivedotcom Well, you could have done a combo...resistive\capacitative dropper lol

      2. bigclivedotcom

        The resistor is possibly doubling up as a heater to keep the electronics dry.