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How to Reuse Washing Machine Motors (2)
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- Опубліковано 30 бер 2016
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Paypal-Donation Link: goo.gl/wq74oG
Wikipedia Article "Revolutions per Minute"
en.wikipedia.o...
Source for cheap wire wound potentiometers:
www.pollin.de/s...
Hey guys, new episodes about this topic are now online:
Salvage a washing machine motor+transmission:
ua-cam.com/video/H_JV7jTH4wU/v-deo.html
Inside a Washing Machine Motor:
Pinout, Teardown, Explanations and Experiments:
ua-cam.com/video/CtulRqznbzI/v-deo.html
where is the AC video?
Hi,
I love your videos, they helped me a lot.
I too have a motor (from a Siemens washing machine) like you showed.
I opened it to determine the windings leading to the pins and identified them.
However, when I wire the field and rotor windings in serie and apply 12V/4A from a lab power supply nothing happens.
I read thyt these motors start running alredy from 4V upward.
What am I doing wrong, eg., how do I have to connect the motor to make it run (ultimately , after testing with 12V DC on 230V AC)?
I want to use the motor to power a wheat grinder.--Is such a motor actually suited for this purpose, or shoud I rather use another kind of motor (vacuum cleaner motor or a induction motor)?
PS
one of the brushes of the motor is quite worn low, but it is still touching.
Does this affect the behaviour in regards to the afore said?
The Post Apocalyptic Inventor
This is a way to recycle metal sheets from the side of an old washing machine: technorattuf.blogspot.com/2018/11/good-way-to-recycle-washing-machine-and.html
I found an interesting patented very easy design, (3.848.168) from Friedrerich Hornung, for torque and speed control. Ten components, no chips.
This brings back memories of my early tech training.
There I learned about series and parallel motors, and the wondrous beast typically used in trains, a compound motor.
The series motor, as you have found, will keep on gaining speed until it either self destructs or reaches a friction/load limit. It has very high torque and is how most starter motors are configured in cars.
The parallel motor can be used for "running at speed", and is perhaps a more suitable configuration for speed regulation? (ie field winding in parallel with armature winding)
The compound motor was where the old speed control lever found in electric trains was found.
The speed control was actually a huge switch which used changed motor configuration from series configuration for excellent starting torque then as the operator advanced it it became a combination series/parallel configuration (somehow), the the final position was a parallel configuration for normal running (without incessant acceleration!).
You may recall the jerks if you ever rode an old electric train (mind you German trains are far superior to our trains downunder!)
So to cut to point, have you tried using the windings in parallel?
I also believe reversing by swapping the field connection would still work OK with AC.
+Ray Jones I would imagine that the field winding in these kind of motors would saturate the stator iron and overheat itself with full line voltage applied. Half voltage ok, perhaps?
love your videos,, studied electronics in college and your videos make more sense, and the intro is so awesome.
I'm hooked. What I like is that you explored an idea, measured your outcome, realized where you needed to redo things, and moved forward to refine your solution.
Love your in-depth videos! You always include the right answers to the questions the viewers might have and it's very obvious that you spend a lot of time and effort in trying different approaches to every problem. Herzliche Grüße aus Schweden!
Thank you for going to all the trouble to test out various circuit designs and, importantly, telling us why they didn't work, or didn't work well enough. You have put a lot of work into this project. I look forward to seeing your control circuit using the TDA1085C.
Very good, I didn't have a problem with RPM vs Frequency of Rotation but I can imagine it was a little confusing for some, at least now everyone should understand it.
I'm wondering if the motor would be easier to control if it was running on DC?
+James Lamb I remember that DC series-wound motors had serious problems with overspeeding when used in railway traction (with rheostatic control) until the introduction of thyristor choppers.
To regulate the rotation of the motor, you need to read back the voltage sent by the tachogenerator built into the motor. Then, you need to compare it to the reference voltage, and integrate the output of this comparator with respect to time. And lastly, control the firing angle based on the integrator output. Very simple ;)
PS: Also, you CAN get the frequency of revolution of the tachogenerator using a single schmitt trigger, fed by the output of an inverting BJT amplifier. And you can convert this frequency into a voltage, with relative accuracy with an integrator and a peak detector.
I am in california so for some reason your accent just makes you sound really smart. even tho you are clearly a smart guy your accent just makes you sound smarter, I love your channel by the way, I found it completely at random and I am a subscriber now!
Wow! Great video series, very well done. Especially the explanation of physical quantity and units of measurement. I'm going to look for all your videos and watch as many as I can.
Thanks for the video. I am in the final stages of fixing a broken GE washing machine. I is a very complicate machine. The controller uses a pic to control its speeds, rotation, etc. It has a single stage ac motor with 3 leads and a thermistor to protect it from overload. If it becomes too hot the pic turns off the current and issues an error signal. It uses a solenoid to engage the the spin of the tub for drying. The controller has 2 triacs which somehow is used to reverse the the direction of the motor during agitation. One winding on the motor is used for normal agitation helped by the triacs for switching direction. The solenoid is used to engage the tub along with the second field winding to increase the speed of the motor for the spin cycle. The motor uses a bipolar capacitor to supply extra current for starting up the motor. Hope this helps.
Just discovered your web site. Love it. Took German many years ago im Gymnasium and quite enjoy the German translations for technical terms. I only get about half of it, but like challenging my memory and German vocabulary. Keep it all up. It's great!
Excellent caliber of content. This guy is completely correct. RPM is not a unit, its a ratio between a semantic and a unit.
A unit must be the same for any case. In the case of a revolution, the function of revolving might mean 2*pi rad to you, but it actually describes angular velocity. Dividing by a time unit (RPM = angular velocity/time) only gives you a number of something per time. It does not give you a unit of measurement of something per unit of measurement of something. Frequency however describes cycles, with the term cycle describing a reoccurring repetition of an event, at a specific point usually identified by the starting point of measurement. If this confuses you, just remember - revolutions are dimensionless.
This gentleman is being very clear, and correct, about something which many people are confused about. This is the sign of someone who truly understands the concepts at play.
This level of precision and clarity may seem petty and trivial, but if someone is responsible for your life and safety, when designing a bridge or home power plant, you will spend a great deal of time and money trying to find this rare type of person.
love your videos. I have spent every evening this week watching them and I will be watching all of them as soon as I can. I confess to being a "womble" and can't help myself from looking in skips and fixing what I can; tvs, drills, computers, hovers... not because I can't afford to buy them, just for the challenge. if you know of other channels like yours please let me know! Mark
Repost for visibility:
The problem with the thyristor circuit in this video is that once the AC is rectified to DC, there's no way to commute the thyristor off once it has been triggered They simply do not work properly with DC because the current must fall below a specified minimum to commute off. The second problem is that once full wave rectified, there is no simple way to measure back EMF as it is always mixed in with the rectified DC.
A couple of ways to attack the problem is force thyristor communtation by pulsing the rectified DC. Probably would be easiest by ditching the thyristor altogether and switching to an SMPS whose PWM is controlled by the Frev measured by the Hall effect sensor. In essence building a SMPS controlled by Frev.
The other possibility is to switch to a TRIAC before the bridge rectifier and controlling the firing angle using a non zero crossing opto-triac like a MOC 3021 or the like. Since the TRIAC is on the AC side, it'll commute at 100 Hz. And since it's a TRIAC, it'll commute on both wave phases giving the circuit full power once rectified.
The only thing I'm unsure of there is the control circuitry to map the Frev to the firing of the opto TRIAC.
Hope this helps...
Your videos are amazing on several different levels. I know this is a few years old but I've watched this one and all your others multiple times. They're brilliant! Thank you!
At 17:26 it looks like the wire connecting the fuse enclosure to the screw terminal on the protoboard is fully tinned. It's a little hard to tell, but in case it is, please take a moment to read up on why that's a bad idea, especially in high voltage circuits.
Crimping a ferrule onto the end of the wire would be fine, but solder is not a good replacement. It doesn't behave like a typical metal does under pressure. It doesn't push back against the screw terminal with constant force the way that, say, a solid copper core would. The solder will show a little elasticity at first, but it's actually slowly yielding to the pressure, creeping away from the contact point.
If you're lucky the wire just falls out of the terminal at some point, but more likely you will see a buildup of contact resistance over time (hours, weeks, years, it's anyone's guess really) and before you know it you've invented fire.
And that's why you use spring washers when tightening a wire to a wiring post.
I'm from S. Georgia USA and I like your accent, especially when you say "MOTOR"
Great explanation. Also the "RPM" and safety well mentioned. Thank you!
Knowlage is so useful in the electron world. greetings i have learned so much! and descovered an instructor who makes the conection of general familuarty and actual this is how it works easy to understand Thank you
Jd ... USA
Would this circuit or the circuit in the previous video also slowdown a hand circular saw or a miter saw ??? (I'm interested to make the saw go slower to cut metal with metal blade)
I live in Alabama, USA and I appreciate your explanation of RPM and Hz. Thank you.
Diese Upload Zeit... passt perfekt in mein Schlafrhythmus :)
How was I able to translate your comment?
“You can’t use RPM, it’s based off the minute!”
“Frequency is better is based on the second, so metric, much proper”
Diese Waschmaschinen Motoren sind genial. Gerne mehr davon. Da kann man sicher noch was schönes draus bauen.
have you checked with an oscilloscope if the thyristor turns off in the full wave circuit? In the half wave circuit it turns off because the negative half of the AC reverse biased the thyristor. In the full wave circuit the bridge rectifier keeps the voltage in the positive half so it may not turn off at all. This would explain why the control doesn't work.
you did a good job of cleaning the motors! I have never seen one that clean!
seriously how do you keep your laboratory and workbench so clean??
mine it`s 3x messy than that!
He’s German.
For the microcontroller communication: How about using two opto couplers? They offer a decent amount of isolation at least up to several kV and can be fast enough for serial communication and just about any switched mode power supply has them, so you could get them from dead power supplies for free (+ they are cheap).
Is there a way to find an equivalent IC of the TDA185c ?
Nowadays, the TDA1085c seems to be obsolete.
Some motors also have a thermal fuse which monitors the temperature of the field coil windings.
4:30 Now I'm confused. I though Hz was cycles per second, so really exactly the same as rpm (multiplied by 60 of course)??
What are you doing supplying the TIC106 (SCR) with full wave rectified supply to the triggering circuit, while the fullwave circuit is not filtered and some zero crossover may occur and allow the SCR to extinguish current flow there may be enough back EMF voltage causing the SCR to continue to conduct. Lose the rectifier and it might run with a little stability. Better still change the circuit and use a Triac with a Diac feeding the Triac gate and it will be a better control.
If you were to use a gate drive transformer from a 3e5 torroid to drive a high voltage power fet you'd have isolation from a tl494 control circuit and the motor power, you'd need a largeish core for say a 4khz pwm frequency, the feedback generator on the motor can be wired to the input side of the tl494 and also be isolated.
A lm2917 frequency to voltage convertor could be used to convert the frequency from the tacho generator to a voltage feedback signal for the tl494 to create a closed loop speed control circuit.
Probably also a good idea to use another torroid or a rewound mains transformer as a current transformer to limit the max current in the motor.
Thanks for explaining some of the finer points for understanding in this video. This is often lacking in UA-cam videos. I wish you success in your quest to find a good circuit to control the motor's speed, because I have a washing machine motor that I removed from the machine and so I am following this series of videos with great interest.
Thanks also for the advice about reclaiming the more expensive
components of that washing machine controller and disposing of the rest,
and that is exactly what I will do.
It is a shame the newer washing machine motors often get disposed of when they operate perfectly using the proper connections and controller. Like many others, I want to repurpose my motor.
Thank you very much for your useful and informative videos.
I live in India where the mains power is 230V AC. So, I can use your circuits without any modification. Some years back, I removed the motor from my old washing machine (with 5 wires) and my plan is to use it for a bench grinder. I am eagerly looking forward to your final circuit to run the motor.
Me too! Mine has 5 wires + ground wire, but no way to tell which is which...
Sir, you are profoundly gifted for EE
The full wave circuit didn't work because the thyristor doesn't see a proper 0V crossing which it required to turn off. Try putting a few diodes in series with the motor...each will shift up the zero crossing by 0.7V. They will need to be able to support the full motor current.
To isolate an Arduino from your high voltage circuit you could use a photodiode/phototransistor combination.
I apologize for any possible frustrating comments you might have with my stubborn people . I enjoy leaning from intelligent individuals like yourself, especially when they have as many skill sets as you have mastered. I look forward to all new post apocalyptic inventor video's . thumms up 👍
SI units are more than metric units. They are a scheme of dimensional coordination to make scientific calculations easier. So that "force varies in proportion to mass multiplied by acceleration" can be "f=ma" when SI units are used.
What about chopper controlling AC through nicely beefy and voltage proof mosfets? Big Mmsfets would require being driven via transistors from an Arduino board, there would be several stages where you could split the higher voltage circuits from the low voltage parts, whack in optocouplers etc. Effectively, you would replace the rectifier diodes by mosfets you control from a low voltage circuit. Like this, one might even be able to eliminate the initial pulses on start up in software by slowly cranking up power via PWM. Looney idea, or would that be feasible?
I like many enjoy your videos a special gratitude and thanks for discussing RPM and frequency. I look forward to the completion of this series if you decide to go forward.
I have access to many of these motors. So, I would like to re-purpose some of them. I would like to make one a bench grinder and two perhaps a low end all purpose saw in a table housing for quick cuts in pine or hardboard. Not much torque needed. Also it is a good learning experience to re-use something instead of spending money on something when you do not have to.
Maybe the reason why the circuit was not behaving as you expected, is because there is no zero crossing for the thyristor to stop conducting even when the gate signal is removed?
Frequency of rotation is the number of revolutions over a fixed period of time. Time is a component. It could be revolutions per second, per minute, per hour, per day, per week or even per year (earth year). This method is easier to understand for non-engineering people.
What you are talking about is angular velocity. Another way of measuring the same thing. Radians per second, per minute, per hour, per day ... and so on. This is more common in the engineering fields.
+Dan Burch Frequency of rotation is the number of revolutions (cycles) per second and its unit is Hz.
The first comment is the way you explain the success and the downfall. you are a good teacher.
Hey, sadly the people who complained about the RPM's are in most cases not smart enough to understand what you explained about the F-Rev... I uses the RPM number for many things I believe it was created for, if I have a bearing shaft I want to turn & the spec's on that shaft say that the bearing will self destruct at anything over 2000 RPM then I need to know the RPM rating of the motor, of course that goes without saying that those RPM's are achieved when the motor is powered up with the proper voltage, at the proper frequency & phase... Keep up the good work....
The other thought I have is whether it is possible to increase current through the rotor windings at a lower voltage by pairing up the commutator segments by soldering a link on the segments outside of the brush running line (2 or even 3 in parallel). The question is whether magnetic timing would be adversely affected, causing simultaneous attraction and repulsion due to the wider magnetic field on the rotor?
I have a large variable speed fan with a burnt out motor, would a washing machine motor be a good replacement?
Can you connect a variable speed controller to a washing machine motor and mount a fan blade on it? Will it burn out because of the speed controller? Will it have enough RPM to blow air? Thanks
Here in the US most of our washers now day follow 2 Topologies either Brushless inverter driven 3 phase motors or Split phase induction motors I don't remember ever seeing AC universal motors in clothes washers I have seen a few in dish washing machines .
you are missing a lot of those links you promised to include in the description. most of which i am interested in watching
the flickering on the screen could be coming from the switching power supply being so close to the tubes while you have it open. also I would check the wiring from the power supply to the boards. you may be grounding out somewhere.
I just discarded an old leaking washing machine last week!
I should have keep some of the good parts inside... :(
Hi TPAI!
I was thinking about a closed loop system to control these motors.
Basically, it would consist of a TRIAC circuit to control the motor, which gets triggered by the output of an op-amp.
The op-amp non-inverting input is connected to a reference voltage set by the potentiometer, while the inverting input is connected to the output of a frequency-to-voltage converter, which gets connected to the tachometer.
I think that it would work fine, with a nice speed regulation.
Alternatively, just search "Hotpoint speed module" on Google Images, some of them can be reverse engineered quite easily and consist of just a few components (BTW, they also work in closed loop and can be found on E-Bay for very cheap).
Hope this helped and keep up the great work.
I liked and subscribed. I dont know the reason for so many strange and negative comments. I Understood your terminology about frequency of rotation immediately. I had no reason to question it. I like your videos, and I was looking for a solution to using an old Indesit washing machine motor I had lying around. It too had many wires and I couldn't find any information about it so I gave up on it. Im glad I never tried to power it up now having seen they are not as safe or easy to get going. I did a resistance test on the motor and found it had 1 common wire and 3 winding wires. I guess It could have gone horribly wrong if i tried to shove 240v through any of them. I only wanted to use it as a generator. It did light an led if you spun it by hand lol:D
I get permanently excited from your videos.
How much power can you get on the motor? The one I have says 240V, 2A, so only 500W from something that heavy. I am using 2 DC supplies at different voltages. Increasing the current through the field windings significantly increases torque and reduces rotor speed but when I got to 36V/10A, something didn't smell good and I stopped. Any thoughts on this configuration?
sorry i spoke out (abt the 'frequency of rotation') on the first part of the video. it was the first video that i saw of your channel, and i have since come to realize that, i was confused and said something without enough research or resources. i meant no offence or harm. thank u for correcting me and my confusion in this video.
Looking forward to the rest of this series.
Looking at an ST7 MCU to do motor control at the moment. They do zero crossing detection!
Hey, I'm planing on building a little car powerd by two Batterydrill motors. I'm pretty sure they are Uni motors aswell, aren't they? do you think I can bring them to have enough torque for a small vehicle? even with the standard controllers wich are built in? and if not can I do this with a washing machine motor?(I will find a way to get one) or would I even need two of them? Thanks in advance
Blasulz1234
Since rpm is not standardized in the ISO system, and you are having trouble with this, I have a suggestion for an ISO improvement. Using Hz for revolutions per minute is confusing and wrong! Herz is the measurement for how many times something occurs in a second. From now on we can use 'Pechtold' for revolutions per minute. It is not named after a scientist, but it is named after a politician, a notorious Dutch politician, well know for this changes of mind and going the other way when the time comes.
what about a phase locked loop where the signal is picked of a coil activated by a magnet which is divided by eight which feeds back to one side of a frequency comparator and a clock generator set to the speed of rotation wanted which voltage controls the TRAC.
Would it be possible to use one field winding in series with the rotor and one winding in parallel with the rotor plus series winding. So the motor would then be wound as a compound wound motor. This would stop it running away as series wound motors always do. There would be no need for electronic speed limitation then. Would this work?
Great. Wish I'd found your videos 15 years ago! Used to love playing about with this. Only one question - whats with the gloves? ;)
what you need tot look for is a bauknecht toploader washingmachine and with a brown knobcluster 1980's to 1990's, they have A slower running universal motor and B a rotaryknob to ajust the motorspeed while centrifuging. all the parts are there , just cut the wireingloom.
hi, Sir. I don't know much about these motors, but I remember tearing them apart as a child, long ago. back then, there were only two circuits per motor, a high torque and slow speed, and then a low torque high speed circuit which didn't rely upon feedback to control it, instead the motor was set at a high speed according to the resistance of the gear and belt friction and load caused by the actual weight of wet clothing. I think you possibly should separate these two circuits in your motor instead of trying to control both at the same time. if this motor is truly universal like a power drill, then maybe all you need is a power drill kind of circuit. ? I love your channel, have a good day. :-)
Gristle Von Raben this comes from a cheaper machine just universal brushed motor nothing else, it's not one of those miele "muet" made in Italy motors with three in axial series like years ago :-)
Why don't you just use a 555 timer in a PWM configuration to generate a 1000 Hz square wave? Then use a potentiometer to vary the duty-cycle of the square wave. Feed the output into a power-transistor configuration to power the motor. Rotating the pot will change the speed of the motor.
Fish out of Water why? very simple. your 555 does not have feedback. as he explained once, if you try to use a complicated circuit you have to isolate your feedback circuit.
Danke für deine Videos! Sie sind sehr interesannt, gut rescherschiert und nachvollziehbar. Ich hoffe ich habe auch irgendwann genug Zeit, Platz und Ausrüstung um es die gleich tun zu können. Ich finde deine Videos inspirierend und motivierend. Danke dafür!
Why is the field winding split? Do they short or skip a section of the field winding to higher the rpm, like field shunting of a series motor?
There is 60 seconds in a minute 60 hz is 1 RPM wither the rotation is physically centrifugal periods or the transition between the two levels. IG f can be stated as hz or (RPM*60)=f
So true on the custom program micro-controller. Yes reuse parts but you may find them purpose designed minimum and not robust enough for your reuse.
.
Have you ever tried to separately power stator and rotor windings with two independent DC sources (when you already have connections), as I can see you are very familiar with electronics, so it will not be a problem for you to make two DC sources (maybe PWM based) with controllable voltage. And then you first connect stator windings and measure current while increasing dc voltage (nothing connected to rotor, and do that step fast becouse of overheating), when current stop rising decrease voltage a little bit and leave it like that (I think that's posible way to find correct stator current) . After that you can start to apply voltage to rotor windings, and as you increase voltage (in fact current, but you understand what I think) the speed of the shaft will increase and relation between them will be "linear". If you want higher speed after reached maximum with this metod of control, you can decrease stator voltage and speed will be increased. IMPORTANT don't ever leave stator winding without voltage because motor could speed up and fell apart, very DANGEROUS!!! Sorry becouse of bad English
Love your videos. It is just real life that some problems are harder to solve than others.
Could you use a capacitive dropper/divider instead of the resistor divider? Have you tried it? It would eliminate the need for power resistor and wire wound potentiometer.
I have a washingmachine controller board with an atmega smd chip on it, it is a little pcb with the chip on it, it looks a little like an arduino pro mini and its mounted on the big pcb. But i didn't try to reprogram it, would be nicer to read it, to see how they manage the programs, bcs its harder to program a washing machine than we think, i have seen a project where a programming pro tried it over a long time. An idea is to connect all pins to an arduino and just watch what happens, try to find the i/o 's then simulate all inputs.
Das Video..... ausgezeichnet.!!! Danke.
Why run it as a series motor? Why not separately excite the field coils with a constant current and run the armature on PWM rectified mains?
In the old days washing machines just had 1/4 horse induction motors that could be pulled out and just plugged in and used on my lathe. I managed to salvage several before they all disappeared.
Now I firmly believe that the cast effective solution and by far the easiest, is to buy a small three phase motor off ebay and a small single phase to three phase controller with speed control. This gives you a simple safe and reliable solution.
Exercise treadmills have permanent magnet motors running on chopped DC and are very controllable. They are very small for their power too.
Really interesting. Makes sense considering there is a lot of different things that effect rpm. I didnt really understand how anyone could get an exact unit of measurement then there is so many things. Is it just that its not a good idea to use rpm when things get big? Althought its useful to use on the working edge of what ever it is spinning? (I have lots of learning to do)
Reusing a WM motor is for some other purpose. Hence not convinient to use the WM control board which normally uses microcontroller programmed for a specific purpose. Rpm is generally marked on motors. It is a sort of commercial unit.
here's a quick idea :
tachometer -> frequency to voltage converter (monostable circuit fired by the rectified output of the tacho) -> divide a 50/60hz sin wave by it ->pwm -> opto-isolator -> switching a rectified (diode bridge and capacitor) 600VDC to the motor.
Great videos on motors, I had a lot of questions and you answered them. Thank you for being thorough.
I have a 6 lead (5 brown + earth) Siemens motor from a washing machine. I'd like to use it to build a tool, however even after watching all your videos I am not sure how to power it, how to know which lead would be which (I guess without taking the motor apart), and how to control it. I might not need variable speed, however it sounds like it needs something to maintain constant and not runaway speed under load / no load. Did you get any further with your circuits, or is there an idiots guide for a quick hook up somewhere? Thanks, and really enjoyed the videos. Mfg. Dave
Is one (2 leads) of them perhaps a cetrifugal switch? Spin the motor with a drill while ohming out the pairs of leads. If one pair shows continuity while the motor is turning, wa-la, that's the centrifugal switch. Jump it out. I will guess the other two pairs are start windings and run windings. The start winding will run the motor with the centrifugal switch open. When the centrifugal switch closes, the run windings are energized. Just a guess.
Very good video !!!
I have a question: The motor that I´m using has only 4 pins (beside the 2 taco ones). Does it mean that in this motor the field windings are connected inside ?
Thank you in advance for the answer !!!
If I understand it correctly you're lowering the gate voltage with the back EMF of the motor while the thyristor is not triggered. Right?! ...and you can't drive it on the lower region, however the same circuit worked with half wave... My guess would be that the 22uF capacitor doesn't have enough time to drain before the thyristor is triggered again, so it fails to regulate. Have you tried 10uF instead of 22uF?! or even 4.7uF
Actually the problem is that once the AC is rectified to DC, there's no way to commute the thyristor off once it has been triggered They simply do not work properly with DC. The second problem is that once full wave rectified, there is no simple way to measure back EMF as it is always mixed in with the rectified DC.
A couple of ways to attack the problem is force thyristor communtation byt pulsing the rectified DC. Probably would be easiest by ditching the thyristor altogether and switching to an SMPS whose PWM is controlled by the Frev measured by the Hall effect sensor.
The other possibility is to switch to a TRIAC before the bridge rectifier and controlling the firing angle using a non zero crossing opto-triac like a MOC 3021 or the like. Since the TRIAC is on the AC side, it'll commute at 100 Hz. And since it's a TRIAC, it'll commute on both wave phases giving the circuit full power once rectified.
The only thing I'm unsure of there is the control circuitry to map the Frev to the firing of the opto TRIAC.
Hope this helps...
This is the guy I want to hang out with when the world goes nuts. Survivor !
Great experiment and your topics are very helpful. Can you show how to change the direction of the motor rotation.
i know most be a weard question but can yuo make a electric fence fault finder o maybe a voltmeter for a lecture of 20 kvolt wich is the limit for security electric fence ???? please it will help alot
An opto-isolator could provide a safer coupling to an arduino.
Unfortunately, my electric knowledges are very week, but I understand a lot o things you explain, so I thank you for this ... Im trying to find a help for fix a multiprocessor that works with 2 speeds, 110V ac, 475W, my main question is to know how to connect the wires for feed its coils ...
Build 2 of the half wave regulators parallel them up in reverse and use a stereo potentiometer to control them both. Viola! You now have a full wave regulator.
The motor that you are trying to control is a series connected motor, sometimes referred to as a universal motor. These motors are very dependent on the load for speed control. Other examples of this type of motor are automobile starter motors, vacuum cleaner motors also forklift motors. If you refer to a torque speed curve of this motor type you will see that unloaded the speed is very high. Another name is traction motor. They are very useful in high torque low speed applications.
How to separate or remove the white plastic sensor that is glued or attached to the rotor shaft without breaking it? Could someone answer this question for me?
can you not use a plug in to mains SMS fan speed controller?
one plug system abd also there is a dual SMS fan speed controler with temparture controler and cut off temp.?
go from sine to square then regulate a blanking between the positive then cap/blanking then negative the wideing/stretching/accordion effect to determine the speed
+glen buchanan
Is this a PWM controller?
If I've followed along correctly the problem is not so much to do with the shape of the wave but that the motor enters an "uncontrolled runaway" state, because it lacks any control, unlike an AC induction motor. It will increases speed until it can't physically go any faster and will, shortly thereafter, fail. I guess turning it on and off rapidly (PWM) would control its speed but would it be good for the motor?
slope between positive negative slopeing down from positive slopeing to negative then sloping upto the positive you can vary the lenght and yes pulse wave modulation kind a like delta wye the motor is always running
Great video ! I learned a lot of things about theses motors. thanks.
I believe your problem is simply trying to control DC with an SCR. If you want to use DC, then use something like a trench IGBT. The SCR does not have the ability to reset itself at lower speeds because the motor commutator is still allowing current to flow through the circuit. A more sophisticated approach would be a closed loop speed controller. It's more complex, but very accurate. You could dial in any speed increment you wish providing it is within the resolution of your D/A converter.
I think converting to DC, followed by a PWM speed control would work. I use that to vary the speed of my Lionel toy train set that uses a universal motor- it is low voltage. A rpm encoder could feed back to the PWM speed control.
You're my spirit animal, sir, thank you for your efforts and the great videos 🤙
The Post Apocalyptic Inventor
You did a great video, really great.
But I am not so good in electronics, the speed control unit looks very difficult to me to realize ( as it looks very difficult to find these parts here in my country).
Can you update this topic maybe with a new way of approaching it or a new solution?
Just sharing a thought: if you find a cheap way to reduce the angular velocity of a universal motor (removed from a washing machine) maybe I could make, also for cheap, one rain water pump. I have already the motor and one drill water pump laying around…
You'd probably find it easier to just re-purpose a washing machine drain pump.
I am just curious what could be the average lifespan of a used washing machine motor running at full speed? Thanks for your quick response
If it is German can outlive us.
Don't German car's Tachometers register in RPMs? I have never seen a car's tach say Hz