How a washing machine door interlock with time delay works. (not a wax motor)

Like most of the components used in home washing machines the door locking mechanism is ultra cost optimised and refined for cheap and easy manufacture. Yet it performs three separate functions. Locking the door, enabling the machine when the door is fully locked and unlocking the door after a time delay to allow a spinning drum to come to a halt before it can be opened.
This particular lock is used in many European machines including Hotpoint and Indesit.
On the basis that these assemblies are mass produced I suppose it makes it viable to use them in other applications where you need the same interlock and time delay feature. The use of a PTC heater probably means that the mechanism can accommodate a wide voltage range.
Failure of these door locks is fairly common, especially if an attempt has been made to force a door open prematurely. They're fairly straightforward to change if you're technically inclined. Some may just require removal of the top of the machine, but some may require removal of the front too, sometimes including the sealing ring which is often held in place by a spring tensioned wire.
If attempting to replace a lock then make sure you get the exact replacement for your machine's brand and model number. Also make VERY sure the machine is unplugged before attempting a repair. Traditionally washing machines were a significant cause of electrical accidents because they are an essential item in the home and can cost quite a lot to have repaired, which encouraged DIY attempts. The older machines had a lot of exposed live metal components in them due to greater mechanical complexity than modern units and cost-optimised nature of the design. Add the fact that you are reaching into a cramped metal case with wet hands and repairs posed a major electrocution risk to the unwary. Especially when the power was repeatedly turned on and off during testing and then accidentally left on.
Modern machines are much more sparse inside, but still pose a significant shock hazard due to the fact that you're reaching in amongst grounded metalwork in a wet environment.
Modern machines are very modular, so if you are technically inclined and use common sense then you can often repair them yourself with components easily sourced online.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
www.bigclive.com/coffee.htm
This also keeps the channel independent of KZbin's advertising algorithms allowing it to be a bit more dangerous and naughty.

[@A_Casual_NPC]

You're the only man on the internet that can make me watch a 20 min videos about a washing machine door lock timer out of choice.

[@dj_paultuk7052]

Same here, i was hooked.. Haa Boom !.

[@tubularap]

True, same for me. Bigclivedotcom is such a pleasing narrator that these videos should be broadcast in hospitals to sooth the patients. And I'm not even joking.

[@tubularap]

I'll add to that. I can see Bigclive doing inflight airplane videos, taking apart a jet engine and telling how beautiful designed it all is. You know, to calm the passengers ... ;-)

[@LMacNeill]

Right?! And not only watching it, but *looking forward* to watching it before even clicking on it. "Ooh -- I wonder what amazing, interesting thing Clive has found for us today!"

[@urbanweekendwarrior7238]

Whaaat? I click EVERY washing machine door interlock I can find. Who's this clive guy?

[@johnbouttell5827]

Civilization: 1. Fire 2. The Pyramids 3. Washing machine door interlock with time delay

[@oldblokeh]

In the case of Hotpoint and Indesit: ... 4. Washing machine door interlock catches fire.

[@darylcheshire1618]

I saw another version. Man 1. Discover fire 2. invent wheel. 3 Build server

[@SteveBrecht]

"There's only so far a digital zoom can go"... haven't you watched CSI? Enhance... enhance...

[@sebimoe]

1. You laugh 2. AI laughs

[@MrHack4never]

I hate movies etc. that do that, it makes explaining computer problems/errors/weirdnesses so much harder to inexperienced computer users

[@gcewing]

Resolution of digital zoom in TV shows is limited only by quantum effects.

[@kazumahikineet3090]

I hate movies and shows in which every action on a computer makes some kind of noise! For instance when they open up a picture or file and it beeps, would make you go crazy in real life.

[@tubularap]

@@kazumahikineet3090 -- Indeed !! The "enhance, enhance" nonsense is just that; nonsense. But the stupid noises for each digital 'movement' are utter irritation. Reminds me of automatically sliding doors in old space/scifi movies always making electronic sounds to let us know they were there. But at least that has gone now, since we have them in the present.

[@peterweingartner4364]

I've been fascinated by how everyday things work since I was a little boy, so I love your videos. There's so much hard work, expertise, and just plain cleverness squirreled away in the devices all around us we take for granted. Thanks for posting this... and all your other videos.

[@kooseerden3767]

@Joe T the only big problem is the availability of parts, especially for cheap devices. You can replace a lot of electrical stuff but if some mechanic components fail you are screwed most of the time.

[@mauricedaniel7930]

@J0e T as xd

[@lordsummerisle87]

I don't know if you've seen them, but look at "The Secret Life of Machines" with Tim Hunkin. Proper 80s/90s British "I've made this in my damp shed using a mig welder and the contents of the bin" documentaries.

[@GordieGii]

The dark metal piece that sits on the adjusting screw is the bi-metal strip. It arches its back when it heats up.

[@throttlebottle5906]

yep :)

[@johncasor9698]

WOW... i work on washer all day and wonder how these and why they work. and i see now why i have to wait a min or two for the lock to cool down to unlock. safety first on the spinning to stop all the way... and yes renters of homes break off the handle of door or damage the door lock because the think it is stuck shut... and they just pull until something breaks... i repair these doors every month someone gives me a job... Haha... another great video... thank you...

[@stiffcookie]

KZbin: We highly recommend this video. Me: I don't think so... Also Me: Clicks anyway. ... Me again: Well played KZbin....

[@mangamaster03]

Big Clive is great! I love listening to him. He's got the same peaceful relaxing voice Bob Ross does

[@spikekent]

That realy is a genius design. I always though the delay was created by some sort of slow discharge capacitor. Thanks for the explanation Clive

[@stevedavis770]

I always assumed that it was capacitor discharge that controlled the release. Mine (Bosch) take five minutes to unlatch.

[@v8snail]

Fisher and Paykel use solenoid locks but if the mains power is cut while spinning they generate their own power through the direct drive stepper motor. It's a fascinating design when you look at how they do it on the main board which dates back to the 1990's.

[@Kineth1]

Amazing design! A great example of how spending more per unit on design can drop your materials bill and lower your per-unit cost.

[@devttyUSB0]

This was great. I always wondered what sensors would prevent me opening the door of my washing machine when its display said "-0-". It indeed takes about a minute, and is acompanied by a loud CLUNGG sound. Fascinating! No moisture sensors, movement sensors, just a bit of bi-metalic and a piece of plastic.

[@stargazer7644]

Not even a piece of bi-metallic.

[@DavidBrown-nd9mf]

I looked for an email address to send this to, but alas I had no luck. I just wanted you to know how much your channel means to me. A little over two years ago I went through four horrible life changing events. 1st was a terribly nasty divorce from extremely difficult and equally hateful ex-wife. 2nd was finding out I had colon cancer about the time the divorce was being finalized. 3rd I had reconnected with an ex-girlfriend that I had always held a special place in my heart for. She got really close to my mom while we dated and put on the best show of fake emotions I had ever seen. Little did I know the entire thing was just a very well planned and executed plot of revenge. 4th I had moved in with this chick(her idea by the way). The only reason I even agreed was because my parents were moving to the coast to get away from the mountains where we lived for close to 20 years. The day before my first chemo treatment she came home and told me that I needed to get a storage unit and move out right away. Mind you my parents had already moved 4 hours away from me and there was nothing I could do about it. Since the time of these unfortunate events I have been done with chemo for over a year and a half. I've been living on the coast with my parents for almost 2 years. All that being said it brings us to the immense value your channel holds for me. I've always been a tinkering guy that has always been interested in how things operate and function. After those tragic events I developed a sever case of PTSD, anxiety, and depression. I can't leave the house without someone being with me because I will suffer a crippling panic. Since I really haven't been able to leave the house very much I've started tinkering pretty heavy to keep myself busy so keep my mind off every thing that's happened. Your channel gives me me the same thing every day. I appreciate you and your channel. Keep up this great content and keep it coming.

[@bigclivedotcom]

I've noticed a pattern of cancer being associated with a stressful life. You may have made the right move. Don't underestimate the freedom of single life.

[@DavidBrown-nd9mf]

@@bigclivedotcom Very true. I'm sure the stress probably has allot to do with it but I was a master automotive paint technician and transitioned to painting airplanes and helicopters. Supposedly the chemicals and paints I had been using caused it. All I can do now is live the best life I can for myself how ever long that may be. Plus single life isn't so bad anyway. If I want to start my day off with a beer and continue that trend until I go to sleep at night no one can tell me any different. Being of German and Irish decent I don't even have the slightest problem with that.

[@DarrenDignam]

Make the ultimate HOPI meter, with no visible multiplexing, and all the read outs you're most interested in. Pink deathdaptor interface optional!

[@DryLog420]

How about a Hopi Quiktest, that could be verrrrry useful for clive :)

[@DanielA-yt8nq]

Thank you for this detailed explanation. You saved my day. I finally fix my wash machine.

[@dtgoodwin]

It's red hot. Grabs it again, still hot!

[@justvb2]

Absolutely amazed Clive is the best Clive to see. Great engineering, no matter how simple the item is still marvelous to see.

[@_Ben_T]

You have about 70% of all my household electronics questions covered here on YT. Good job sir.

[@MegaVoltMeister]

I love the fact that you said that no one would take this apart to fix it, but of course you did, as would I. Thanks Big Clive ! Love your videos.

[@Hidden8Knowledge]

So glad i found your video!!! I've tried everything to open my washing machine door, the nylon string trick, the credit card trick, the tapping on the door trick , the green tab (which i didn't have ) but all i needed was to push the wee tab back in thank you 🙏 now to replace the lock 😀 👍 You need to do a short version for people this would save a lot of money and stress

[@daleyurk4369]

How can you turn a boring washing machine door lock into a fascinating dissection? You are an amazing man in a lot of ways!

[@herenow2895]

Thank you Big Clive. I had an issue with the door interlock on my machine and after listening to this video, I cleaned the PTC and associated contacts. Job done, all sorted. Many thanks.

[@rogerbradbury9713]

I repair the washing machines at a local launderette. Most of the machines are the 1980's Electrolux Wascator W74, if anyone knows what that means. With these, the equivalent part of the machine has three microswitches, all normally open. Two are closed by prongs when the door is shut. The third is closed when the locking lever is moved over by a solenoid, preventing the door catch from releasing. All three have to be closed for the machine to run. The delay circuit is a large capacitor and some resistors.This is energised while the machine is running, and feeds the solenoid. When the machine finishes and the power is off, the capacitor discharges, and after about 30 seconds there's a clunk when the solenoid can no longer hold in. Then the customer can open the door. The aluminium door catch and locking lever eventually wear, then you get customers pulling the door open before the machine has finished, and issues where the machine will stop part way through the cycle. The machines are cleverly designed and easy to work on.

[@Miata822]

I love efficient design. Channels like this one go a long way towards sowing the public how things work and the effort that goes into designing even the smallest disposable components. The world would be a better place if more people were curious about the things they touch every day.

[@EggBastion]

"The world would be a better place" it probably would.

[@relph3]

I have been a subscriber of yours for a number of years now. Thank you Clive for videoing this. My Hotpoint 520 uses a similar interlock which seemed to have gone faulty after about 14 years use. I had no clue how the interlock system could be removed from the machine until I watched this video. Also I managed to repair it after understanding how it all actually works. Repairing it was just a case of carefully opening up the solenoid module attached to the interlock and spaying the moving parts and springs with silicone spray. On a side note: I looked after my mum & dad throughout 2022. My dad suffering from Alzheimer's and my mum bed bound, your video of you telling the story of you and your brother Ralph looking after your mum helped me so much mentally. Thank you again.

[@Xaltar_]

Thanks for the video, managed to fix my interlock which had come apart (slammed door) thanks to your teardown 😎👍 Ingenious little mechanism indeed. My PTC thermister had come loose and fallen down into the bottom of the casing along with 2 little brackets. It's only a tiny savings but it saved a lot of complaining while waiting for a replacement 😂

[@Mackinstyle]

I repaired my own dryer a few months back. I was so delighted by just how electromechanical everything was. No electronics. Just big obvious stuff. My cottage oven was the same way.

[@mahmoudbitar6571]

amazing content sir ,, you are the only one on the internet who showing the power consumption of the lock ,, thank you !!

[@tonygibson1671]

I replaced a lid lock on a top loading washing machine that used a pulsed latching solenoid. The solenoid was pulsed to lock the lid before the spin cycle, and then pulsed again to unlock the lid once the tub stopped spinning. If the machine was unplugged during the spin cycle, the machine would remain locked until it was plugged back in and the cycle finished or canceled.

[@yLezTilez]

I blew the plug by my washing machine long ago and have been using a thick cord from a close receptacle. I always leave it plugged in after its done because I thought it needed the power to open, and sure enough, last night, you're video is correct. Awesome video

[@muaries12]

I indeed changed this very same locking device of my washing machine a few months ago. It lasted more than 10years! I opened (obviosly) and the ptc was desintagrated. It was rated for 16A so i thought the entire amperage of the machine was flowing trough this litttle device and deduced had some thermal mechanics (well i was a tiny bit right) Great video man!!

[@mda99das]

I have a bosch washing machine that displays door error and I came across this part DM070 and I had a good look and now I find you actually made a video on it!

[@Suresh-bx4rz]

SIMPLY Awsome!! Well explained, Very clear audio and video, Very Systematic approach, From the basics (including bimetal physics) to the details!! Great job!

[@dsloop3907]

Mother had a Kenmore washer that she bought in the early sixties, and still used it in 1996, when she passed. Had to have the belts replace one time, no other problems, EVER. You could run it with the lid open, no safety interlocks back then. We had more sense than to mess with it while it was running. duh. A clothesline was the only drier.

[@boonedockjourneyman7979]

A sort of physical-thermal analog of the molecular complimentary of enzyme active site binding. Brilliant.

[@simontemplar404]

Nice exploration and explanation of the safety interlock Mr C. It is very useful understanding how a thing works when you are faced with fixing a broken one. I note for those with locks that do not open reliably that the fixes from the comments seem to be : Remove the plastic sliding strip. Or increase the size of the hole in the sliding strip. Or remove the lock pin. Or bypass the lock by rewiring it to disconnect the PTC and permanently apply power to the machine. Or buy a new lock and replace it, they are inexpensive. Note that the machine model name and number needed to buy a new lock are on a sticker on front of machine inside door. To get your stuck door open use plastic cord/fishing line wrapped round door, pushed in with flathead screwdriver - to tug towards hinge side of door on latch. Or slap panel hard to reset lock. There are other methods in KZbin videos. From other videos the method to fit the new lock is : undo the clip round the rubber door seal and push the seal back inside the drum. Undo the screws holding the door lock and fish it out from the gap between the drum and the front plate. Unplug old lock, plug in new lock. Screw new lock back in behind panel, replace door seal, refit clip. My lock is sticking and I will probably buy a new one when I get tired of opening the door with fishing line. Stay Safe :-)

[@seangreaves9069]

Great video, really helped me out when my old interlock switch fell apart on opening. Just couldn't figure out where one small piece of metal went. Even though my switch was slightly different the principle of operation proved the key.

[@victorr.5782]

genius design or not the time lock was so annoying, making me forget about the clothes so often i came here and learnt how to slice out that bitch little piece of plastic. such a relief, thank you Clive

[@maxruff7645]

Better design than my recently failed 'outwardly identical' unit. Mine had PTC & wax in a tiny bellows button (wax motor). Bellows ruptured and wax extruded. No bimetalic strip. Thanks for the dissection.

[@johnsalmons9222]

was thinking that could be done better /simpler with a wax motor. Had to laugh, not at your misfortune Sir, that they managed to shittify that too, thanks for your post, FIYAFE!

[@markflack9191]

Some machines also have an air hose from the water level sensing system to stop the door being opened if the machine has water left in it.

[@ironnam8107]

Luckily mine just turns off the motor, and applies a break to the drum. If i see something i forgot i can open it, and throw it in.

[@erikjohansson1814]

Some machines heat the water too up to 90C.

[@28YorkshireRose12]

My old Zanussi has that! - So is a four way interlock. Five, if you consider that as the water level operates two hydrostatic devices, 1: A hydrostatic mechanical blocker on the door interlock, and 2: a hydrostatic switch that only connects the system controller to mains when the water reaches a specific level, ergo, the machine won't start unless the door is closed, AND, the drum contains sufficient water. Similarly, the door doesn't open if there is water in the drum (power or not), and the system controller is "off-lined" if the drum should lose its water, e.g. a torn hose or bellows connector, or any other cause of leakage, e.g. user drain plug is not fully tightened.

[@TurboTel68]

The old Hotpoint 95 series had a pressure operated interlock that only locked electrically when the drain pump operated and they used to make a weird buzzing noise

[@AngDavies]

@@erikjohansson1814 Clive should get a thermal camera on that strip- at 90c the door might not open either way because of the temperature

[@just_noXi]

Need this exactly today. Thank you so much.

[@hannahranga]

Always cool to see cost optimised safety critical stuff, my day job is railway signalling so also safety critical but anything but cost optimised.

[@MrBobWareham]

Very simple meck one bimetal strip, one heater, one microswitch so simple a clever fellow that designed it we used to replace loads of them when I was a white goods engineer Indesit were always going wrong people would phone up to say I can't get my washing out help nice video as always Clive

[@rameg7]

Thank you Very Much Steve, I had resolved my washing machine door lock issue.

[@bigclivedotcom]

You're welcome Betty.

[@Witheredgoogie]

Some people appreciate fine paintings, I appreciate fine mass produced engineering ..even some beautifully made nuts and bolts can bring me joy... thanks

[@singeslayer8367]

Damn, Clive is good at making mundane stuff look interesting!

[@dan_]

I'm quite scared that Google decided to recommend me this video the day after I had a fight with a washing machine door that wouldn't let me access my clothes. Somebody hold me.

[@SigEpBlue]

Safety interlocks are usually one of the first things I defeat on new appliances. :)

[@ColinTimmins]

Thankyou for explaining this mechanism Clive, I have a better understanding on how it works. Useful knowledge...

[@davepusey]

This was very interesting. Have always wondered how it stayed locked and then unlocked itself, even without any power. Had never considering the spinning drum issue either, had always presumed it was just to keep the water in.

[@gravey07]

‘Lock’ ness monster being drawn. Couldn’t un-see it! 😂

[@wannabetechnician7451]

clives videos are edutainment in the best possible sense

[@johnsalmons9222]

beat me you bugger!!! touche sir

[@starfox6335]

Listening to your voice through Bose speakers makes my desk vibrate like crazy lol

[@4833504F]

Great topic! I always wondered how the door opens with the power to the machine unplugged

[@johngraves2755]

Often wondered how these work it astonishing in its simplicity.

[@SoddingaboutSi]

Its a brilliant and yet frustrating device. That says is for your own safety. Very interesting.

[@SpotTiger]

Modern, more expensive washing machines have drum brakes and an electronic lock that is opened by the onboard computer. When power fails, the washing machine is permanently closed, until you go into the service door and pull an unlatching handle. The problem with these heater mechanisms is simple. When power fails, it'll unlatch, even if the washing machine is full of water. You'll 100% not notice in the dark and open the door. As to failure modes in this mechanism, it's the ceramic block. It will crumble over the span of 10 years (average washing machine lifespan), collect electrical arc marks and stop heating up enough to latch.

[@ElectroXa]

I wondered how the lock system was made, now I know how it's made :-) Thanks BigClive for this video

[@TRX450RVlogger]

I tried to by pass mine one time. I fucked it up and some how fried the damn Circuit board.... luckily I found the part replaced it and then called to have it warranted and they never even noticed I was in there lol. The guy was like “Yeah some how the Circuit board that shorted out”. 🤣

[@ehsnils]

The amount of annoyance that timer has created compared to the few Darwin award candidates that had put their appendages in a spinning machine is incredible.

[@jeremyvoshage2410]

Finally a yoga block being put to proper use

[@turboed350]

i was wondering if maybe the ptc lost connection from that bimetallic strip since it had that other strip it kinda hooked down to but glad you showed at the end what was going on i was kinda lost thinking the strip bent the other way before that point lol. also iv seen press or punch press video that showed them mass producing little spade ends and electrical connectors for relays and stuff and the amount of steps they go through to get the end part is crazy and just how accurate the little parts are amazed me. after seeing the inside of that kinda made me think back to how all that stuff is made. its very thought out and just so crazy how fast they can make that kinda stuff.

[@stevefox3763]

I always thought that it was done using a solenoid and capacitors as the lock still functions if the mains supply is removed , nice to learn how its really done

[@NOWThatsRichy]

Thats exactly what I assumed too!

[@m.k.8158]

I'm fairly sure that SOME machines DO work that way...for example Wascomat machines(used in laundromats), show a light on the front panel after the machine stops, which goes out to indicate that the door is unlocked-the light going out is accompanied by a loud "THUNK" sound, which I'm pretty sure is the solenoid being powered off and and the latch releasing. These machines are front-loaders, of course.

[@aaaaaaaaaassssssssdf]

i love taking relays apart and cleaning them up. it's saved me a ton of money keeping 30+ year old nissans on the road

[@simontay4851]

Saved you A LOT of money.

[@aaaaaaaaaassssssssdf]

Simon Tay a ton of Zimbabwean dollars. but really one is an imported Nissan and the door relay is not available in my country at all. would be pricey to ship it from Japan. and good luck finding some of the main relays in a 280z at all

[@dennisjones1961]

Great video , very well explained , good job Sir,👍

[@peglor]

If you can get your hands on the thermal cutoff switch from an electric shower there's a more impressive version of a bimetallic strip. Instead of a strip they use a disk with a slight dome, which pops from convex to concave at a given temperature, which pushes down a button under the disk, which opens contacts to disconnect the power to the shower heating element.

[@bigclivedotcom]

I did a full shower teardown. Including inside the heating chamber.

[@felixcat4346]

I just took mine off and jumpered it out so the microcontroller will think the door is closed this way I can adjust the amount of soap I add and put in extra cloths if I wish. Save us from the nanny state. The PTC thing can also be found in modern fridges. It prevents the compressor from starting until it gets cool.

[@bigclivedotcom]

The PTC in the compressor might be acting as a solid state start winding controller. There's often an anti-stall thermal switch too.

[@felixcat4346]

@@bigclivedotcom Clive, if you cycle the compressor on and off by unplugging it too frequently, the relay which includes the little disk, starts to click but the compressor wouldn't start for a while. Then if you come back a while latter, the fridge is working as it should. It acts as some thermal protection for the compressor.

[@redpheonix1000]

@@felixcat4346 I never knew that! There's often a "quick chill" option on freezers, that when pressed starts the compressor (probably not all it does but it doesn't matter in this instance). Turning it off and back on, it doesn't start right away. I didn't realize that was a PTC too! That's really neat.

[@bigclivedotcom]

@@felixcat4346 The compressors will stall if turned off and on again while running because of the pressure of the gas. They need a pressure balancing time between runs.

[@frankowalker4662]

Brilliant! I thought they just used a solonoid. Live and learn. Thank you!

[@frankowalker4662]

@pmailkeey LOL

[@suadcokljat1045]

Exactly what I wanted to see and learn. Thanks. Cheers! S

[@AntonioClaudioMichael]

Great video Clive

[@abelincoln95]

True that. My front load washer won't "click" to allow opening until after the drum is idle for about 5 seconds. AND, if even while it is just filling with water, you have to press "pause" and wait 5 seconds before you can add more clothes. Genius!!!

[@Thermalions]

Lucky you. Mine takes roughly 2 minutes to cool down*, which is super annoying when the drum resistance means that it stops spinning within 5-10 seconds of being stopped/having power cut. * Ambient is typically 25-40 C depending upon season/weather.

[@cheeto4493]

Glad I watched to the very end!

[@Lyndalewinder]

Interesting and potentially useful video - thanks for posting

[@MrRadioAct]

Many North American models use a wax motor to "lock" the door shut. The time delay created by the cooling down of the wax before the door will unlock ensures the drum has come to a complete stop if it were on high spin when power was lost.

[@Crack84baby]

Very nice video. I always wondered how they made the delay even when it's unplugged.

[@brianallen9810]

I've got one of these things on my top loader. It's a real pain, the washer is micro processor controlled and it has a speed sensor on the motor that senses when the drum is rotating and as long as it's rotating it will not go to the next cycle nor can you open the top. Unfortunately when the motor stops it keeps spinning under it's own momentum for about 5 minutes not including the time delay in the micro processor. I've had the thing apart to try and bypass it, but it's impossible. So I just took the interlock actuator off the door and permanently put it in the switch itself. Now I can open the door whenever I want, no kids in the house, only competent adults, so it's not a threat.

[@Petertronic]

How fascinating! For many years I always assumed it was a solenoid with a capacitor that caused the release delay even when un-plugged. That's why you should never assume :)

[@NOWThatsRichy]

Thats exactly what I assumed too!

[@Petertronic]

Thinking about it, the 3 watts constantly used by the lock is wasteful, considering the millions of them in operation. Perhaps another fail-safe solution should be found.

[@valimakm]

We use Yokogawa WT310e power analyzers for measuring single phase equipment. It can display four different measurements at a time but I think it is in a different price range.

[@johnf3326]

Well I'll be buggered! What I never knew I wanted to know! And a non-LED based video from B.C.

[@GordieGii]

LOL

[@maicod]

he could pimp the lock with one though :)

[@PhilXavierSierraJones]

Some newer washing machines will automatically turn on and apply inductive (regenerative) brakes if the drum is spun and the door is opened. It's quite a clever safety feature.

[@wimwiddershins]

Great stuff. I bet this has many previous iterations that it builds upon. It makes me wonder what these will look like in another 20 years.

[@avejst]

Nice design indeed Thanks for sharing👍😀

[@petroskaneas1880]

the best analysis

[@simhong]

Thank you! Finally I could fix doorlock malfunction of my dumbass samsung washer with your video!

[@monomille1]

Interesting I recently had to fix the switch on my top loading machine. It was also easy to replace by taking out two screws that keep the lid closed and lifting the top of the machine up - it is hinged at the back. The switch just fits into a rectangular slotted hole under the lid (no screws needed) and it is Normally Open and is actuated by a pin when the top closes. No time delay needed. Similar price. Satisfying when you can avoid an expensive visit by the official fixers to do something so simple

[@pareshpatel5690]

Thats very nice informative video Sir, I have a similar problem and I have ordered new switch from Amazon

[@BenCassell]

Great video!! Thankyou

[@floraflex1216]

Hey Clive, you have such a beautiful base-y voice, I surely can listen to this romance all day/night

[@cam2213]

My job is to repair laundry equipment. You have no idea how many people complain about a safety item such as this. One of these to be replaced is about ~$300.

[@kennyatkins6448]

The problem with these interlocks is when they fail in the locked position you can’t open the door and you have to get inside the machine and try and break the lock off. I’ve had to do this many a time. ( I’m a retired domestic appliance engineer )

[@johnarmstrong3782]

I hate the time delay. I never could understand it. The damn door won't open for ages after the program has finished and the drum has stopped. There should be a a way to override it so I can OPEN THE BLOODY DOOR!

[@wktodd]

it also allows the washing to cool to a lower temp , which also extend the door lock time.

[@rlowens]

This video shows you exactly how to do that - just disconnect the heater wire. Saves a little energy too!

[@victortitov1740]

@@rlowens disconnecting the heater won't work on my machine, because it has special contacts to detect if the lock has engaged or not (and it won't start unless the lock is engaged). I had to enlarge the hole in the metal plate to defeat the lock.

[@SeersantLoom]

I have toploader made by Electrolux and it seems to have a latching relay lock. As soons as the machine has done its thing, it simply clicks (more like small bang actually) and you can open it. It would be interesting to see one of those locks dissected. I guess these might have 2 relays inside or some clever way of one solenoid + permanent magnet magic.

[@accardosappliance5440]

If the motor doesn’t have a rpm sensor then they just guess a generic long time. Units with rpm sensors unlock when the drum stops.

[@wktodd]

anyone else screaming "the spring bit is bimetallic":-)

[@WyvernDotRed]

Just wanted to comment that that pushes the copper part on the dimpel which acts like a microswitch. Don't have to comment that anymore, because he edited that in, but I still will :-P

[@whitcwa]

Yes, but I knew Clive would get it right eventually.

[@SirDamned]

Finally something that is relevant to my life

[@28YorkshireRose12]

Mein Gott, Helga! That is a very simplified interlock. You'll have to take my word for it, because I ain't wreckin' me washin' machine just to prove it, but my 25(ish) year old Zanussi has a far more sophisticated interlock than that, though the PTC pill is the same, it also has two microswitches and a hydrostatic blocking mechanism. . The basic principal is clearly the same, but in my machine, the time delay is around 5 minutes before the lock will release, this I assume is because this machine has a "Boil" option, and therefore needs longer to cool down from such a high temperature - with only one thermal interlock, it's a case of catering for the worst case scenario. A very interesting video to see, and quite enlightening.

[@hugogabriel5367]

Muy buena la explicación del funcionamiento

[@garydiver3729]

Superb video, pity I found it after I had the exact same issue with identical door interlock and managed to work it out eventually! Never mind

[@arongooch]

The Secret Life of Machines hosted by Mr Clive

[@RFC3514]

For anyone not familiar with the actual series: en.wikipedia.org/wiki/The_Secret_Life_of_Machines You can find all episodes online, although the links from Tim's official site seem to be broken.

[@tubularap]

@@RFC3514 -- Very interesting series, never heard of before. Thanks for the tip and link.

[@RFC3514]

It's surprisingly obscure, considering how amazingly good it is. I've used bits of it in lectures about digital image processing and software engineering, because they illustrate some key concepts so well. I even tried to pitch a similar show to a producer a few years ago, just so we could try to convince Tim to be a technical adviser. :P

[@tubularap]

@@RFC3514 -- Ha, great idea to get Tim to be an adviser to a revival series. I like older documentairies about technology from before everything is about processors and internet-protocols. The attention is then often truelly focused on the mechanics of the time, and not yet distracted by what's all possible in the digital realm. I found the same in docus about the history of the bicycle. Up untill those from the 70's the docus are about the history much more than the ones from later, that are way more about the new trends that were then coming up, like mountain bikes, new lighter materials, etc. New docus are interesting in their own right, but they have lost that focus of a time when looking back was the (only) thing to do since there were no new trends yet.

[@RFC3514]

It wasn't really a revival series (BTW, TSLoM is not as old as it looks; it _looks_ like something from the 70s, but it's actually from 1988-1993), just similar to it in some ways. What I like about TSLoM is that it doesn't focus on history in abstract ("this is what happened on this date"), it's mainly about how it works, and follows the history of how each type of mechanism was invented (or made possible by another invention or discovery). For example, most people have no idea that the fax machine was invented before the telephone, but knowing what technology goes into each one makes that pretty logical. That (the history of the fax and telephone) also drives home the fundamental difference between digital and analogue processing (i.e., the way digital is inherently more robust and _easier_ to transmit reliably), which, again, is something most people don't understand. TSLoM is mainly about technology and _engineering,_ or at least history from an engineer's point of view. And that's sort of what I wanted to do (adding a "maker's" or "hacker's" point of view at the end) in the new show. But it's really hard to produce independent stuff for TV these days (archival footage can be insanely expensive unless you're working for something like the BBC, that has its own archives), documentaries sponsored by specific manufacturers invariably end up as long-form adverts for those manufacturers, and the History Channel / Discovery / National Geographic / etc., seem more interested in producing bad fiction disguised as documentaries (ghosts, aliens, cursed treasures, conspiracy theories, that sort of crap) than anything educational about science and engineering. I guess they've figured out it's cheaper, and people will watch whatever is on.

[@trey1531]

The Hopi is a hallmark of the channel. You can't get rid of it!

[@hadireg]

simplicity is a resolved complexity

[@kfftfuftur]

good thing you explained the scredriver . . . people might have thought it lights up bacuse your left hand was life and the right one neutral

[@bigclivedotcom]

Could have been a floating earth or you could have been physically live if you touched something that was damaged or defective.

[@WarpRadio]

the bi-metallic strip is the little piece behind the PTC which touches the adjustment screw.. the strip pushes the PTC pallet into the copper spring latch.. this is done for a couple reasons; 1.. allows a safety contact to the PTC and 2.. keeps the bi-metallic piece hotter for longer (but without having the piece get too hot which would melt or deform the plastic housing.. the copper end will dissipate the excess heat and allow for thermal-expansion)