Great video once again Vince :) 6:25 this is a filter capacitor to avoid adding noise to other equipments connected to mains, it is required by EU laws (you can remove it thow, it will work but you'll be feeding noise to other electronic equipments). The resistor is meant to discharge the capacitor, otherwise you would get a shock if you touch with your hands on both plug pins. Inside basically you have a heating resistor that is divided in at least 2 parts, to create a voltage drop, this voltage drop is then used to feed the bridge rectifier that feeds power to the motor while is being heated up. The motor speed can be set by getting a heating resistor windings ratio or it can also be made by passing current throw a diode, making a voltage drop (0.7V), slowing the motor down, it depends how it's made, but usually is made out of the heating resistor windings . 12:50 the problem might be with dust in these contacts, which will make it to have more resistance, and it will heat up faster (more resistance = more heat), making it break the circuit. 26:41 You can't redo them, they will break, also you can't touch this resistor with your hands, you will put oxidation on it and it will break a few uses later. You can climp it thow, that's the only way, never tried it but it probably would work. Also you need to have careful about cutting this since their total resistance interfere with the total power, if you make it shorter, you'll make it heat up more, burning down the house :) also you have to make sure the windings are not touching, otherwise you will create a short. 37:19 *if you reduce the resistor, you'll increase the current since the mains voltage remains the same, and you'll put more or less voltage to the motor, not because of the total resistance that has changed, but because of the voltage drop across the resistor split has been modified, so if you decease it in one side, you might end up adding more voltage, but if you decrease it on the other side, you'll end up removing more voltage, it's all about the ratio.
Great fun putting a device with a HDD for instance next to something completely unshielded and pumping out a lot o' dirty rays hehe And people with pacemakers used to be the thing to watch for as unshielded devices used to send 'em off heart racing which is why up until not so many years ago you had to turn your mobile fones off in hospitals, and petrol pumps as in the right weather ambience your fone could spark off a treat from the pump earth...
The big fat diode is being used to block the AC when it's going in one direction, so only half the power (when it's the correct polarity) will get to the heating coil.
Once had a clothes dryer that the large heat coil would burn into. I would put the wire back together with a small wire connector and wait until it broke again. After 6 connectors, it got replaced. Great videos you do. Thank You...
I took out the heating element on an old hairdryer during the hot months and just put in a switch with a 12v power supply, so I could have a handheld fan :)
Hey Vince, Just a suggestion. I think you should try to repair a damaged laptop one day. I know you already repaired a DVD drive on a desktop but a laptop is kinda cool inside. I really like your work and I enjoy watching you more than TronicsFix because you go through the process. Thanks for the hard work and keep it up
I second that, and a HDD, I was watching a bloke do a micro SD card on a HDD repair channel and he has a soldering iron Vince would love with a very very small but powerful curved tip abs spot on for PS4 and other console repairs.
@@frenchfry7631 Um wtf.. Tell me, how am I begging for likes? (Or how is anyone replying to me begging for likes?) I bet you 20$ you can't tell me how I am begging for likes, pins, hearts, or replies?
@@Mymatevince not sure if you fancy a look but my mother in laws Denon DVD player has developed some odd intermittent faults, like the image shuddering and randomly fast forwarding the entire film. Drop me a message if it's of any interest Keep up the great work.
I've just gotten one of these fantastic mats for Christmas. It's pretty slick, quite substantial and really cool to work with. I was pleasantly surprised at the magnets located at strategic locations. My wife is a clever girl. Cheers, mate!
@@mlight6275 Vince appears to be the S-160 version (300mm). The link below has three sizes. One smaller than vinces, on larger, and one the same size as vinces. Kaisi Heat Insulation Silicone Repair Mat with Scale Ruler and Screw Position for Soldering Iron, Phone and Computer Repair Size: 21.6 x 13.8 Inches www.amazon.com/dp/B07DGTJ463/ref=cm_sw_r_cp_apa_i_KDwdEb5FRR23B
This is what I remember about how the different heat settings work. You are correct in there being two different heating coils. The first heat setting only powers one coil which is usually shorter and therefore less resistance for heat to be created from. The second heat setting should be only powering the second, longer coil which has more resistance and can create more heat. The third heat setting is activating both coils at the same time which creates the most heat. The key is the switch and what coil is being powered. The reason the one coil was working was that it had its own power supply which was fed from the switch on the low setting. This can also vary from blowdryer to blowdryer but I think that is what is happening here.
You are right I can confirm this, also adding that the small element his the contact for the fan motor. So if you disconnect the small element, the big one will still work on setting "2" (lets call it 1-2-3) But by disconnecting the small elements the blower fan motor wont spin :P
Thinking about it, it's probably that switch you were looking at!! It's a bimetalic switch probably - to cut off if too hot. Something important I should say - When plastic mounts are broken on something like that 2nd one, I wouldn't tape it up and use it that way! It might be OK as a quick temporary thing, but tape can break / lose its grip with heat etc. I would hate for someone to get injured (or worse) by it coming apart whilst in use! The other point related to equipment with heating coils - if something bad does happen, and someone dies, or your house burns down - your insurance may try and blame you! I thoroughly enjoyed the video as usual!!!! =D It's a bit different with other electrical products as generally they aren't dangerous products - eg. PSU in a PS4, protected by fuses - user cannot get near the components. But electric fires, irons, hair dryers can be lethal, as its easier for the user to come into contacts with elements etc! With regards to safety of a short hair dryer vs long neck one, I think its fine tbh! My understanding is because its blowing outwards it would be hard for hair to go inside it, and you need a complete circuit - the hair is only going to contact 1 side of the connection, and hair probably isn't conductive the same as skin. One other problem you can have when you are missing part of an element - it will lower the resistance of the remaining element, meaning that can go hotter than it was perhaps designed for. (I think - I could be mistaken)!
Sorry to sound like a scaremonger btw - great video, I just had to point out those things!! The last thing I want to hear is some terrible accident happened! I can just imagine the episode now - "How to fix my wife after she got electrocuted by the hair drier - boy shes mad!"
You're right. The less resistance between the endpoints of a coil, the more current will flow through, as per Ohm's Law: I=V/R (current = voltage / resistance). So if originally it had a 100 Ohm resistance, and lost 10 of it, it would go from 240/100 = 2.4 A to 240/90 = 2.667 A. And that means that the wattage would increase from 576 W to 640 W. And more wattage means more heat. However, the switch may play a role as well. If it reduced its own resistance from 16 to 1 on high settings, that means that the total wattage on medium and high (with the reduced resistance) is 240/106 = 2.26 A = 543 W and 240/90 = 2.667 A = 640 W, respectively. Almost a 100 W difference! And that's another 100 W that will generate heat! And that's per coil for the high settings, so a total of 1280 W of wattage vs 543 W for medium (if the coils are run in parallel instead of in series). Bonus Calculation: Originally then, if we assume the resistance between the coils was 100 each, and one was active on medium settings and both were active in parallel on high settings, that means that: Medium: 240 / 116 = 2.06 A = 496 W High: 240 / (100*100/(100+100)) = 4.8 A = 1152 W. The resistance formula for two parallel resistors (or coils in this case) is used and is (R1*R2)/(R1+R2). Otherwise you just take the reciprocal of the reciprocal sum of all resistors, in this case it's: 1/((1/100)+(1/100)) = 50 Ohms. It would not be viable if they ran in series, because we'd get the a lower heat dissipation per volume of coil for double the volume of coil, so the same amount of heat (plus some due to the resistance loss in high settings): Medium: 240 / 116 = 2.06 A = 496 W. That can be used as the thermal dissipation equivalent for one coil, which means 496 watts equivalent. High: 240 / 200 = 1.2 A = 288 W. 288 W * 2 coils = 576 watts equivalent thermal dissipation, so merely 80 watts extra in thermal dissipation (assuming the calculations and theories are correct). EDIT: Added information about how resistance is calculated for two resistors in parallel. EDIT2: Tidied up the spacing between paragraphs... I hope.
Not scaremongering at all Chris. All very valid comments and worth pointing out. I added a warning at the beginning of the video just to reinforce viewers NOT to copy the technique used in the video. I just wanted to prove the fault. The workings of it were more interesting than I thought they would be even though they are designed as a throw away item. Never be afraid to point out stuff in the comments that were done in the video whether dangerous or just done wrong. It helps us all :-)
It has a thermostat with bimetal plate (strip) that bend and cuts out when it overhead in the path of heater element, and when it cools it make contact again. The problem comes with ageing and constant heating it can't return to its original shape and cuts out earlier. It's main function is to protect melting of plastic if the hairdryer overheat. You could adjust that thermostat but the plate already loose its properties so you can just short it or remove it, but you have to watch for overheating. The speed is controlled through heater windings, different configurations provide different resistance and speeds on motor or use diode to partially rectify the AC which lead to dropping voltage to half. If you draw a schematic of this hairdryer you will understand everything. You can't solder Canthal wire (that's the name of heater wire) but you can wrap it or squeeze brass metal tube on two contacts you trying to join, but shorting the length of it will lower its resistance and will burn easyer. Yes you can add another pice to sustain the proper resistance of it.
Brilliant technixbul. Your comments are always so knowledgeable and helpful. Thanks for taking the time to share them with me and everyone else. Cheers mate :-)
Vince.. if you ever suspect a "Heat sensitive breaker switch" connect your continuity tester across the suspect breaker and then use your heat station to heat the breaker up, if the circuit opens with very little heat applied to it, you need to replace it. BTW.. To clean coil resistors "Heating Elements" I used a basting or small painting brush.. Hair dryer Elements here in Australia can cost "$30~$50" so it's cheaper to buy a new and what's more better quality hairdryer as it seems over the years they have dropped dramatically in price..
Somebody else mentioned that electric hairdryers sold in the EU need to have a filter capacitor to reduce the amount of electrical noise fed back into the electrical supply, I may have understood the post incorrectly. Do you know if this is the case with hairdryers sold in Australia? I ask because for Christmas in 1989 Mum got a hairdryer, about a month later I was lying in Mum and Dad's bed listening to the radio and Mum was drying her hair in the en suite bathroom, the radio reception was completely obliterated by interference from the hairdryer, the clock radio was set to FM. and it was making a horrendous noise.
Bi metal strip is the cut out switch by fiddling with it you may have cured it for a time. The diode is a half voltage cut so is your speed switch The capacitor in the front is for noise reduction on the line. Also it blows out the front so it will not suck hair in the front. The wire you can get an apprentice to solder them together, was an old trick played on the uninformed
I think you got it in one with how the three heat levels worked - there was only a single difference between levels one, two, and three of that switch, the only difference between one and two - level three was the same as level 2 in terms of resistance, but obviously also added the extra coil on top of it.
The same thing is in kettle switches. Ours started overboiling. It was just the bi-metallic had some corrosion on it. Listen and you can hear the little click after a few seconds when the kettle has finished, that's that same little strip.
I use a hairdryer because of my style of hair and I been using them for some time now and when a hairdryer does that it's usually because while the blow-dryer was on somebody covered the part where the hot air comes out causing the thermostat to become faulty
You can save the winding to make yourself custom high current resistors, the winding is already being used that way you only need to shorten it to a measurable point in ohms that you want. I also recommend to save the heat resistant tower and sleeve, it might handy if you want to test the resistor quickly before you make it more permanent.
You could test the bimetalic strip by touching it with your soldering iron and watch it ping, you can check the temperature by gradually increasing the soldering iron temperature.
I don't think you can solder a broken heating element, I think you'd need to tack weld it back together because solder would probably just melt once you turn the dryer on.
Yeah, without that the only thing you can do is do a mr. twist and hope it won't break once those wires heat up. Not sure if it would really just melt away but i would not risk it (since hot msolder in hair is not fun)
That component in grey box at @5:18 ( and at @6:40) is a class X suppression capacitor, you can find out more about them on google, typing EMI or RFI suppresion capacitor.
It is possible to replace elements yourself. Just purchase some Nichrome wire the same gauge and wind it to the same diameter and resistance value. But you have to use crimps instead of trying to solder them to the wires. Do this at your own risk of course.
Metal expands when heating up, which is why you need the heat resistant string within the coils. Without the string the coil will start sagging, thus shorting out with the next coil. The coil wire has a specific resistance per meter. That means if you are shortening the coil it will have a lower resistance which draws more current and gets hotter.
Please could you tell me the name of this material? I am trying to order I already found the Nichrome 0.1mm for the small coil but it also has that little (nylon) string inside it and I wonder which one to buy, if you could help it would be amazing, thank you !
Not only the diode, but also the heating wires are connected to the mains voltage. So, yes hairdryers can be potentially dangerous, especially near water. That's why your need a good earth leak switch in your home.
You can keep the heating wire to cut plastic and foam stuff. Just connect a piece of the wire to your bench power supply. The wire is made of constantan, which is a nickel-copper alloy. It has a positive temperature coefficient, which means its resistance goes up with temperature - so it protects itself from just burning up - as it heats the current goes down.
BI-Metallic strip is the heat limiter maybe some more up market hair dryers can be using electronics to control temperature, the hair dryer is like a low tech version of your hot air rework station without electronics.
The diode on the heating element is used to halve the power. When the diode is switched in series with the heating element it will only allow half the AC cycle to pass trough, blocking the other half.
Wont it get really hot taking in account the power that goes in it? Usually for good hair dryer 2200W 230V. And then the poor diode is blasted with hot air. That should be the first thing to fail. 🤨
2200W @ 230V is about 10A. With a typical diode Vf of 0.7V that makes 7W. However, the diode only conducts for half of the AC cycle so it'll dissipate 3.5W. So, nothing a plain 5W diode can't handle. A decent design will place the diode in between the blower motor and the heating element, causing cold air to be blown over the diode, cooling it rather then heating it.
@@unimportant5122 The problem (especially with the small pink one) is that it's directly in the firing line of the hot air blowing past it. And I'm pretty sure the heat from the coils that heats up the air is going to affect the diode sooner or later. And the diode of the pink hair dryer is indeed right in front of the outlet end of the airflow - the designers weren't particularily clever about its placement. 😒
That one big fat diode is a half wave rectifier. A full wave bridge rectifier has four diodes with all the bands pointing to the positive side. Great video, Vince! Curiosity is a great teacher. :) Your caution makes that you're probably not a contender for the next Darwin award, but stay safe any how! :)
Depending on the raw wattage you could possibly make a new coil. In China you can buy anything in component form from simple stuff like bespoke capacitors to heating elements, element coils and all sorts if you don't mind wading thru hundreds of pages on Alibaba and the forty thieves. These things are super cheap as a unit whole and tbh its better not to risk it, if it was on 110v it wouldn't be such a disaster but 240 angry pixie power running through your hand to ground is very dangerous. 1970's hairdryers were designed to be fully servicable, 2010's ones unless they are top tier professional ones are designed to be thrown away.
it will be, one coil for the first setting the other coil for the second setting and both coils for the third setting. The heat difference between the coils is caused by the resistance of the coils.
@@Mymatevince I missed the part at the start of you looking at the second hair dryer, In which you say that the first heat setting is cold. If it is then it is just, First setting no coil, second setting one coil and third setting both coils. The cold boost button will spin the fan/motor faster. The capacitor limits spikes to the voltage when you use the switches. The impedance of the motor causes the voltage to spike when you first apply the voltage to the motor. Putting a capacitor across the motor or in that case the supply to the motor smooths the voltage line and greatly reduces spikes.
On the hair dryer on that mains cable going in to it there's a filter capitor and a discharge resistor across it the hair dryer has three elements the first and second have wires inbertween to give the right heat mode then four third speed there all powerd giving more heat
The initial fault might have been that thread (fiberglass) that herds the nichrome coil into a somewhat linear coil as it sags after heating, might have just broken due to vibration and fatigue. It is supporting a longer proportion of the coil and is at a terminus. String snaps and that section shorted. Plausable?
YES!!! Its exactly what his happening inside the one I am fixing right now, the little white thread inside the coil his broken in hald and because of that the little coil his sagging (loose) and burnt in some areas because it shorted together, so that string his fiberglass is it? Im searching to order this material, I already got the Nichrome 0.1mm to redo the coil. But could not find what that little white string was, thank you I might find it now, I also notice that there his kevlar string for sale that can resist up to 800 degree F, wondering if it would be better or too much.
A "kit for young kids"...build your own mains powered hair dryer, what a great idea....can't stand kids. Seriously that pink thing looks like a bloody death trap, don't mean to scare you but cheap electrical goods and kids...Hmmm, I think I would be happier if the kid had the bigger better built one. But I guess they've been using it for years, so no problem yes ? maybe ? but those coils aren't far away and they're at mains potential, it looks like a toy, which it aint...just sayin. Your spot on with the "Bimetallic Strip" That sort of stuff I tend to treat as "disposable" I no that's not good practice what I mean is I would use the bits and bobs elsewhere, like the motor and switches then just buy a new one for the family....I was writing this as I was listening and its great ! you were saying all the sensible stuff that I was thinking, clearly you have no intention of using them again just another great video, thanks and a great new year to you all.
when theirs a resistor on a switch weather its a light or a motor lower resistance will allow a motor to go faster higher resistance will make it slower same applies to potentiometers for volume and brightness
hi vince this comment is unrelated to this video but i wanted to ask because i can trust your opinion, i was finding a short in my playstation 2 yesterday, i removed a chip and tested the caps around it but the short was still there, so i put the chip back on the board and took off an electrolytic smd capacitor, but the short was still there and the cap was testing fine, BUT...putting the cap back on the board with hot air.. i applied a little pressure to the top of the cap to make sure it had a solid connection and it blew up in my face.. could you shed a little light on what i did wrong so i dont repeat the mistake in future lol its made me nervous to try again... again sorry for the unrelated comment
@@Mymatevince The only substance that most people come across that has negative thermal expansion is water, between 0 degrees C and 4 degrees C. That's why ice is less dense than liquid water and so ponds freeze from the top.
I would imagine a room heater isn't likely to pose the same danger as a hairdryer used by someone with wet hair, wet hands, maybe in a steamy bathroom with humidity up.
Or you can get "that winding" for free. They are used in public restroom hand dryers. Cameras in restrooms are forbidden so you could easely kick one off the wall and take the coil home. Then you can measure the resistance and cut it at the needed lenght. You can easily calculate the needed resistance with Ohm's law. You know the voltage and power of that unit. 😂😂😂
I've never understood why electric hair dryers are so terribly noisy, is it because they have such a small fan that spins at a high speed? Is it because the fan moves air at a fast rate? Why are they so loud?
They use cheap universal motors, mainly made of light, vibrating plastic. The fan in your computer is brush-less. That means no carbon brushes touch the rotor. So, this fan is more quiet. Of course the high speed also plays a role.
you only got a bit of hair off the fan now if you did manage to separate the fan blade from motor you would have found the hair tightly wound round the spindle cos the motor should rotate more freely than that yet its not hence why the thermal cut out activates more than it should
Great video once again Vince :)
6:25 this is a filter capacitor to avoid adding noise to other equipments connected to mains, it is required by EU laws (you can remove it thow, it will work but you'll be feeding noise to other electronic equipments). The resistor is meant to discharge the capacitor, otherwise you would get a shock if you touch with your hands on both plug pins.
Inside basically you have a heating resistor that is divided in at least 2 parts, to create a voltage drop, this voltage drop is then used to feed the bridge rectifier that feeds power to the motor while is being heated up.
The motor speed can be set by getting a heating resistor windings ratio or it can also be made by passing current throw a diode, making a voltage drop (0.7V), slowing the motor down, it depends how it's made, but usually is made out of the heating resistor windings .
12:50 the problem might be with dust in these contacts, which will make it to have more resistance, and it will heat up faster (more resistance = more heat), making it break the circuit.
26:41 You can't redo them, they will break, also you can't touch this resistor with your hands, you will put oxidation on it and it will break a few uses later. You can climp it thow, that's the only way, never tried it but it probably would work.
Also you need to have careful about cutting this since their total resistance interfere with the total power, if you make it shorter, you'll make it heat up more, burning down the house :) also you have to make sure the windings are not touching, otherwise you will create a short.
37:19 *if you reduce the resistor, you'll increase the current since the mains voltage remains the same, and you'll put more or less voltage to the motor, not because of the total resistance that has changed, but because of the voltage drop across the resistor split has been modified, so if you decease it in one side, you might end up adding more voltage, but if you decrease it on the other side, you'll end up removing more voltage, it's all about the ratio.
That correct
Great fun putting a device with a HDD for instance next to something completely unshielded and pumping out a lot o' dirty rays hehe And people with pacemakers used to be the thing to watch for as unshielded devices used to send 'em off heart racing which is why up until not so many years ago you had to turn your mobile fones off in hospitals, and petrol pumps as in the right weather ambience your fone could spark off a treat from the pump earth...
The big fat diode is being used to block the AC when it's going in one direction, so only half the power (when it's the correct polarity) will get to the heating coil.
half wave rectification , used to do it on older soldering irons to save the element
FixDaily, this is brilliant. Thanks so much. Let me try and pin this comment :-)
Once had a clothes dryer that the large heat coil would burn into. I would put the wire back together with a small wire connector and wait until it broke again. After 6 connectors, it got replaced. Great videos you do. Thank You...
I took out the heating element on an old hairdryer during the hot months and just put in a switch with a 12v power supply, so I could have a handheld fan :)
Hey Vince, Just a suggestion. I think you should try to repair a damaged laptop one day. I know you already repaired a DVD drive on a desktop but a laptop is kinda cool inside. I really like your work and I enjoy watching you more than TronicsFix because you go through the process. Thanks for the hard work and keep it up
I second that, and a HDD, I was watching a bloke do a micro SD card on a HDD repair channel and he has a soldering iron Vince would love with a very very small but powerful curved tip abs spot on for PS4 and other console repairs.
would be nice and if he needs help , I would help him anytime
@@StevenShaw I also recommend him (ERS) to Vince ... probably half year ago
Yeah yeah keep lying begging for likes and pins and hearts and replys
@@frenchfry7631 Um wtf.. Tell me, how am I begging for likes? (Or how is anyone replying to me begging for likes?) I bet you 20$ you can't tell me how I am begging for likes, pins, hearts, or replies?
The coil itself is live at high voltage not only the diode.
Keep up the intresting videos Vince!
Thank you :-)
@@Mymatevince not sure if you fancy a look but my mother in laws Denon DVD player has developed some odd intermittent faults, like the image shuddering and randomly fast forwarding the entire film.
Drop me a message if it's of any interest
Keep up the great work.
I've just gotten one of these fantastic mats for Christmas. It's pretty slick, quite substantial and really cool to work with. I was pleasantly surprised at the magnets located at strategic locations. My wife is a clever girl. Cheers, mate!
where did she find it, and details ?
@@mlight6275
Vince appears to be the S-160 version (300mm). The link below has three sizes. One smaller than vinces, on larger, and one the same size as vinces.
Kaisi Heat Insulation Silicone Repair Mat with Scale Ruler and Screw Position for Soldering Iron, Phone and Computer Repair Size: 21.6 x 13.8 Inches www.amazon.com/dp/B07DGTJ463/ref=cm_sw_r_cp_apa_i_KDwdEb5FRR23B
This is what I remember about how the different heat settings work. You are correct in there being two different heating coils. The first heat setting only powers one coil which is usually shorter and therefore less resistance for heat to be created from. The second heat setting should be only powering the second, longer coil which has more resistance and can create more heat. The third heat setting is activating both coils at the same time which creates the most heat. The key is the switch and what coil is being powered. The reason the one coil was working was that it had its own power supply which was fed from the switch on the low setting. This can also vary from blowdryer to blowdryer but I think that is what is happening here.
Perfect explanation. Thanks Sarah1390 :-)
You are right I can confirm this, also adding that the small element his the contact for the fan motor. So if you disconnect the small element, the big one will still work on setting "2" (lets call it 1-2-3) But by disconnecting the small elements the blower fan motor wont spin :P
I think that little one is a bit dangerous with wet hair....you are spot on
Hi Vince, you can get brass crimp barrels to repair Resitive wire ,but it needs cleaning first before crimping.
Thanks for the info Scott :-)
Another nice video Vince, and thanks for the safety advice about fixing hairdryiers.
Thinking about it, it's probably that switch you were looking at!! It's a bimetalic switch probably - to cut off if too hot.
Something important I should say - When plastic mounts are broken on something like that 2nd one, I wouldn't tape it up and use it that way! It might be OK as a quick temporary thing, but tape can break / lose its grip with heat etc. I would hate for someone to get injured (or worse) by it coming apart whilst in use! The other point related to equipment with heating coils - if something bad does happen, and someone dies, or your house burns down - your insurance may try and blame you! I thoroughly enjoyed the video as usual!!!! =D
It's a bit different with other electrical products as generally they aren't dangerous products - eg. PSU in a PS4, protected by fuses - user cannot get near the components. But electric fires, irons, hair dryers can be lethal, as its easier for the user to come into contacts with elements etc! With regards to safety of a short hair dryer vs long neck one, I think its fine tbh! My understanding is because its blowing outwards it would be hard for hair to go inside it, and you need a complete circuit - the hair is only going to contact 1 side of the connection, and hair probably isn't conductive the same as skin.
One other problem you can have when you are missing part of an element - it will lower the resistance of the remaining element, meaning that can go hotter than it was perhaps designed for. (I think - I could be mistaken)!
Sorry to sound like a scaremonger btw - great video, I just had to point out those things!! The last thing I want to hear is some terrible accident happened! I can just imagine the episode now - "How to fix my wife after she got electrocuted by the hair drier - boy shes mad!"
You're right. The less resistance between the endpoints of a coil, the more current will flow through, as per Ohm's Law: I=V/R (current = voltage / resistance).
So if originally it had a 100 Ohm resistance, and lost 10 of it, it would go from 240/100 = 2.4 A to 240/90 = 2.667 A. And that means that the wattage would increase from 576 W to 640 W. And more wattage means more heat.
However, the switch may play a role as well. If it reduced its own resistance from 16 to 1 on high settings, that means that the total wattage on medium and high (with the reduced resistance) is 240/106 = 2.26 A = 543 W and 240/90 = 2.667 A = 640 W, respectively. Almost a 100 W difference! And that's another 100 W that will generate heat!
And that's per coil for the high settings, so a total of 1280 W of wattage vs 543 W for medium (if the coils are run in parallel instead of in series).
Bonus Calculation: Originally then, if we assume the resistance between the coils was 100 each, and one was active on medium settings and both were active in parallel on high settings, that means that:
Medium:
240 / 116 = 2.06 A = 496 W
High:
240 / (100*100/(100+100)) = 4.8 A = 1152 W. The resistance formula for two parallel resistors (or coils in this case) is used and is (R1*R2)/(R1+R2). Otherwise you just take the reciprocal of the reciprocal sum of all resistors, in this case it's: 1/((1/100)+(1/100)) = 50 Ohms.
It would not be viable if they ran in series, because we'd get the a lower heat dissipation per volume of coil for double the volume of coil, so the same amount of heat (plus some due to the resistance loss in high settings):
Medium:
240 / 116 = 2.06 A = 496 W. That can be used as the thermal dissipation equivalent for one coil, which means 496 watts equivalent.
High:
240 / 200 = 1.2 A = 288 W. 288 W * 2 coils = 576 watts equivalent thermal dissipation, so merely 80 watts extra in thermal dissipation (assuming the calculations and theories are correct).
EDIT: Added information about how resistance is calculated for two resistors in parallel.
EDIT2: Tidied up the spacing between paragraphs... I hope.
@@GadgetUK164 Particularly at a time where RUclips is targeting and removing videos for "harmful or dangerous content".
Not scaremongering at all Chris. All very valid comments and worth pointing out. I added a warning at the beginning of the video just to reinforce viewers NOT to copy the technique used in the video. I just wanted to prove the fault. The workings of it were more interesting than I thought they would be even though they are designed as a throw away item. Never be afraid to point out stuff in the comments that were done in the video whether dangerous or just done wrong. It helps us all :-)
Nice one Operational 117 :-)
It has a thermostat with bimetal plate (strip) that bend and cuts out when it overhead in the path of heater element, and when it cools it make contact again. The problem comes with ageing and constant heating it can't return to its original shape and cuts out earlier. It's main function is to protect melting of plastic if the hairdryer overheat. You could adjust that thermostat but the plate already loose its properties so you can just short it or remove it, but you have to watch for overheating. The speed is controlled through heater windings, different configurations provide different resistance and speeds on motor or use diode to partially rectify the AC which lead to dropping voltage to half. If you draw a schematic of this hairdryer you will understand everything. You can't solder Canthal wire (that's the name of heater wire) but you can wrap it or squeeze brass metal tube on two contacts you trying to join, but shorting the length of it will lower its resistance and will burn easyer. Yes you can add another pice to sustain the proper resistance of it.
Brilliant technixbul. Your comments are always so knowledgeable and helpful. Thanks for taking the time to share them with me and everyone else. Cheers mate :-)
Vince.. if you ever suspect a "Heat sensitive breaker switch" connect your continuity tester across the suspect breaker and then use your heat station to heat the breaker up, if the circuit opens with very little heat applied to it, you need to replace it. BTW.. To clean coil resistors "Heating Elements" I used a basting or small painting brush..
Hair dryer Elements here in Australia can cost "$30~$50" so it's cheaper to buy a new and what's more better quality hairdryer as it seems over the years they have dropped dramatically in price..
Thanks for the tips Koala :-)
Somebody else mentioned that electric hairdryers sold in the EU need to have a filter capacitor to reduce the amount of electrical noise fed back into the electrical supply, I may have understood the post incorrectly. Do you know if this is the case with hairdryers sold in Australia? I ask because for Christmas in 1989 Mum got a hairdryer, about a month later I was lying in Mum and Dad's bed listening to the radio and Mum was drying her hair in the en suite bathroom, the radio reception was completely obliterated by interference from the hairdryer, the clock radio was set to FM. and it was making a horrendous noise.
Bi metal strip is the cut out switch by fiddling with it you may have cured it for a time. The diode is a half voltage cut so is your speed switch The capacitor in the front is for noise reduction on the line. Also it blows out the front so it will not suck hair in the front. The wire you can get an apprentice to solder them together, was an old trick played on the uninformed
Thanks Vilhelm :-)
you always have such intelligent, helpful viewers. i just come here for the music
I think you got it in one with how the three heat levels worked - there was only a single difference between levels one, two, and three of that switch, the only difference between one and two - level three was the same as level 2 in terms of resistance, but obviously also added the extra coil on top of it.
I was given an ionising hair drier that was not working so I disconnected the ioniser part and now it works great.
Heat thing is a bi metallic strip Vince same thing they use in room thermostats and portable heaters too buddy great vid again :)
Thanks Pork Bap :-)
The same thing is in kettle switches. Ours started overboiling. It was just the bi-metallic had some corrosion on it. Listen and you can hear the little click after a few seconds when the kettle has finished, that's that same little strip.
I use a hairdryer because of my style of hair and I been using them for some time now and when a hairdryer does that it's usually because while the blow-dryer was on somebody covered the part where the hot air comes out causing the thermostat to become faulty
You can save the winding to make yourself custom high current resistors, the winding is already being used that way you only need to shorten it to a measurable point in ohms that you want. I also recommend to save the heat resistant tower and sleeve, it might handy if you want to test the resistor quickly before you make it more permanent.
You could test the bimetalic strip by touching it with your soldering iron and watch it ping, you can check the temperature by gradually increasing the soldering iron temperature.
Very good idea. Thank you Thomas :-)
@@Mymatevince better u use ur hot air station ;-)
the bimetal thermostat should switch off the heating element if the fan fails
I don't think you can solder a broken heating element, I think you'd need to tack weld it back together because solder would probably just melt once you turn the dryer on.
Yeah, without that the only thing you can do is do a mr. twist and hope it won't break once those wires heat up. Not sure if it would really just melt away but i would not risk it (since hot msolder in hair is not fun)
Just buy a new hairdryer lol!
Another great video, looks like you’ve just acquired a handheld pcb preheater 🤔
That component in grey box at @5:18 ( and at @6:40) is a class X suppression capacitor, you can find out more about them on google, typing EMI or RFI suppresion capacitor.
bi-metallic strips were used in car wiring for indicators . my 1976 escort often needed one replacing.
It is possible to replace elements yourself. Just purchase some Nichrome wire the same gauge and wind it to the same diameter and resistance value. But you have to use crimps instead of trying to solder them to the wires. Do this at your own risk of course.
Loved the video Vince.
Thank you :-)
@@Mymatevince You're welcome.
Metal expands when heating up, which is why you need the heat resistant string within the coils. Without the string the coil will start sagging, thus shorting out with the next coil. The coil wire has a specific resistance per meter. That means if you are shortening the coil it will have a lower resistance which draws more current and gets hotter.
Please could you tell me the name of this material? I am trying to order I already found the Nichrome 0.1mm for the small coil but it also has that little (nylon) string inside it and I wonder which one to buy, if you could help it would be amazing, thank you !
@@djrival819 I have no idea what material it is. sorry!
Not only the diode, but also the heating wires are connected to the mains voltage. So, yes hairdryers can be potentially dangerous, especially near water. That's why your need a good earth leak switch in your home.
You can keep the heating wire to cut plastic and foam stuff. Just connect a piece of the wire to your bench power supply. The wire is made of constantan, which is a nickel-copper alloy. It has a positive temperature coefficient, which means its resistance goes up with temperature - so it protects itself from just burning up - as it heats the current goes down.
It's actually very close, but it his Nichrome Wire, a mix of Nickel and Chrome :P
Just love your videos Vince :-)
Both of these faults are exactly the same as my 2 hairdryers. So will try and copy.
BI-Metallic strip is the heat limiter maybe some more up market hair dryers can be using electronics to control temperature, the hair dryer is like a low tech version of your hot air rework station without electronics.
A bridge rectifier has four diodes, Full wave rectifier is two diodes, and you can use one diode as a half wave rectifier.
The diode on the heating element is used to halve the power. When the diode is switched in series with the heating element it will only allow half the AC cycle to pass trough, blocking the other half.
Wont it get really hot taking in account the power that goes in it? Usually for good hair dryer 2200W 230V. And then the poor diode is blasted with hot air. That should be the first thing to fail. 🤨
2200W @ 230V is about 10A. With a typical diode Vf of 0.7V that makes 7W. However, the diode only conducts for half of the AC cycle so it'll dissipate 3.5W. So, nothing a plain 5W diode can't handle. A decent design will place the diode in between the blower motor and the heating element, causing cold air to be blown over the diode, cooling it rather then heating it.
@@unimportant5122
The problem (especially with the small pink one) is that it's directly in the firing line of the hot air blowing past it. And I'm pretty sure the heat from the coils that heats up the air is going to affect the diode sooner or later. And the diode of the pink hair dryer is indeed right in front of the outlet end of the airflow - the designers weren't particularily clever about its placement. 😒
Thanks for the info Unimportant and the following comments :-)
The mains voltage is a sine wave. The diode cuts of either the top or bottom of the sine wave, reducing the power.
Another great video as always 👍🏻❤️
Nice mate really like your work :), gonna attempt to fix my iPhone 6 battery tommorow and also fixed my xbox one fan :)
Dummy the title says *FAULTY HEAD DRYERS* NOT *FIXING IPHONE 6 AND XBOX 1* DUMMY
Good job on your Xbox repair and good luck on your iPhone
@@Rvthless__ thanks mate
@@frenchfry7631 DUMMY "people who live in glass houses shouldn't throw stones"
The title actually says Faulty Hair Dryers not HEAD DRYERS
That one big fat diode is a half wave rectifier. A full wave bridge rectifier has four diodes with all the bands pointing to the positive side.
Great video, Vince! Curiosity is a great teacher. :)
Your caution makes that you're probably not a contender for the next Darwin award, but stay safe any how! :)
Thank you :-)
Maybe you could stretch the coil a bit so the broken ends would both slot into the next slot and be held in place there.
Depending on the raw wattage you could possibly make a new coil. In China you can buy anything in component form from simple stuff like bespoke capacitors to heating elements, element coils and all sorts if you don't mind wading thru hundreds of pages on Alibaba and the forty thieves. These things are super cheap as a unit whole and tbh its better not to risk it, if it was on 110v it wouldn't be such a disaster but 240 angry pixie power running through your hand to ground is very dangerous. 1970's hairdryers were designed to be fully servicable, 2010's ones unless they are top tier professional ones are designed to be thrown away.
Thanks Ian :-)
it will be, one coil for the first setting the other coil for the second setting and both coils for the third setting. The heat difference between the coils is caused by the resistance of the coils.
Of course, that makes more sense. Thanks PDS :-)
@@Mymatevince I missed the part at the start of you looking at the second hair dryer, In which you say that the first heat setting is cold. If it is then it is just, First setting no coil, second setting one coil and third setting both coils. The cold boost button will spin the fan/motor faster. The capacitor limits spikes to the voltage when you use the switches. The impedance of the motor causes the voltage to spike when you first apply the voltage to the motor. Putting a capacitor across the motor or in that case the supply to the motor smooths the voltage line and greatly reduces spikes.
Don't the three settings control how fast the motor spins and blows out air not the temperature?? Great Interesting
vids btw
Definitely look into getting new hair dryers would not trust the pinks short Barrel and that problem with the other one seems a fire hazard.
On the hair dryer on that mains cable going in to it there's a filter capitor and a discharge resistor across it the hair dryer has three elements the first and second have wires inbertween to give the right heat mode then four third speed there all powerd giving more heat
The initial fault might have been that thread (fiberglass) that herds the nichrome coil into a somewhat linear coil as it sags after heating, might have just broken due to vibration and fatigue.
It is supporting a longer proportion of the coil and is at a terminus. String snaps and that section shorted.
Plausable?
YES!!! Its exactly what his happening inside the one I am fixing right now, the little white thread inside the coil his broken in hald and because of that the little coil his sagging (loose) and burnt in some areas because it shorted together, so that string his fiberglass is it? Im searching to order this material, I already got the Nichrome 0.1mm to redo the coil. But could not find what that little white string was, thank you I might find it now, I also notice that there his kevlar string for sale that can resist up to 800 degree F, wondering if it would be better or too much.
A "kit for young kids"...build your own mains powered hair dryer, what a great idea....can't stand kids. Seriously that pink thing looks like a bloody death trap, don't mean to scare you but cheap electrical goods and kids...Hmmm, I think I would be happier if the kid had the bigger better built one. But I guess they've been using it for years, so no problem yes ? maybe ? but those coils aren't far away and they're at mains potential, it looks like a toy, which it aint...just sayin. Your spot on with the "Bimetallic Strip" That sort of stuff I tend to treat as "disposable" I no that's not good practice what I mean is I would use the bits and bobs elsewhere, like the motor and switches then just buy a new one for the family....I was writing this as I was listening and its great ! you were saying all the sensible stuff that I was thinking, clearly you have no intention of using them again just another great video, thanks and a great new year to you all.
Thanks mate :-) Happy New year to you too.
when theirs a resistor on a switch weather its a light or a motor lower resistance will allow a motor to go faster higher resistance will make it slower same applies to potentiometers for volume and brightness
Don't risk it - cut the plug off and treat Mrs. Vince to a new hairdryer.
What type of 'string' is in the middle of the coils?
I am guessing silica, like what was used in electronic cigarettes as wicks.
You do still have a perfectly working 12v dc motor and all those extra components you can use for future projects should you need, so that's good.
hi vince this comment is unrelated to this video but i wanted to ask because i can trust your opinion, i was finding a short in my playstation 2 yesterday, i removed a chip and tested the caps around it but the short was still there, so i put the chip back on the board and took off an electrolytic smd capacitor, but the short was still there and the cap was testing fine, BUT...putting the cap back on the board with hot air.. i applied a little pressure to the top of the cap to make sure it had a solid connection and it blew up in my face.. could you shed a little light on what i did wrong so i dont repeat the mistake in future lol its made me nervous to try again... again sorry for the unrelated comment
That bi-metallic strip - you could test it by pointing a hairdryer...
Oh. Never mind :).
Maybe it was dropped/hit when it was hot and that had broke those wires?
I have fixed it by using small brass/copper tube pieces and inserted both ends into one piece of small tube piececand I used pliers to crush them
Metals expand when they get hotter, not contract- steel does it by less than brass.
Oh yeah, of course. Thanks for commenting on that :-)
@@Mymatevince The only substance that most people come across that has negative thermal expansion is water, between 0 degrees C and 4 degrees C. That's why ice is less dense than liquid water and so ponds freeze from the top.
Hi Vince can you fix a Vauxhall zfira key fob
Lil advice Vince - don't blow into mics (at least if you want to het soume sound of them yet)... It almost teared my heart out. Poor membrane :-)
I had a room heater (fan with heat coils like those) that had the same thing happen i would not trust it and threw it away.
I would imagine a room heater isn't likely to pose the same danger as a hairdryer used by someone with wet hair, wet hands, maybe in a steamy bathroom with humidity up.
@@dodgydruid it made a spark when the coil broke!
Or you can get "that winding" for free. They are used in public restroom hand dryers. Cameras in restrooms are forbidden so you could easely kick one off the wall and take the coil home. Then you can measure the resistance and cut it at the needed lenght. You can easily calculate the needed resistance with Ohm's law. You know the voltage and power of that unit. 😂😂😂
You've been talking to the kids in my town.
I've never understood why electric hair dryers are so terribly noisy, is it because they have such a small fan that spins at a high speed? Is it because the fan moves air at a fast rate? Why are they so loud?
They use cheap universal motors, mainly made of light, vibrating plastic. The fan in your computer is brush-less. That means no carbon brushes touch the rotor. So, this fan is more quiet. Of course the high speed also plays a role.
You can buy heating coils for hair dryers..
you only got a bit of hair off the fan now if you did manage to separate the fan blade from motor you would have found the hair tightly wound round the spindle cos the motor should rotate more freely than that yet its not hence why the thermal cut out activates more than it should
your answer to the shock situation is the air goes in thru the back & out thru the front so there is no way you can get an electrical shock from it
At 11 minutes: . ... cheaper model. More for children... Oh that's hot...
I laughed more than I should have
;4)
Keep the Babyliss for electronics like screen replacements aso
That is a very very very good idea. Thank you :-)
Try get the Percivic corrals on EBay of the model
The motor in that babyliss hair dryer is not a 12 volt dc motor.
Vince i think its time to just break down and buy a new hair dryer that second one has seen better days!
My guess is bad switch contacts
the spots where the heating element was broken could be clamped together
Im not an expert but the hairdryer might be dangerous but it will be blowing so it completely lowers the chances of getting a shock
I would suggest buy a big hair dryer to dry your kids hair just to be extra safe
U can joint them back with a crime coupler
hi vince if you wanne fix it you need to crimpe it soldering want work it will melt in aflash
Thanks Axel :-)
Sweet
Im the first baby lololol
Hahahahahahahahahahhahaahahhahahhahahaha
@@frenchfry7631 Brag much lol
@@Rvthless__ wait i think i saw you on an dropping a iPhone x on a high stairs comment
turning on hair dryer is pressing down L3 R3 on GTA 5
Yes it is un safe
contacts should be cleaned .diodes should have been checked.
Government energy saving feature.
Nuclear explosion at 18:30
Take it down the tip
I bet it your air dryer
Ffs vince throw somethin away lol
Vince that’s your hair dryer not ur daughters 🧐
Remove the hair that is preventing the fan from spinning freely
Z
Hey Vince its muktaar I am a subscriber of you please talk about me and about that ps3 I'm shore to buy a new one
First