1:40 demonstration, 6:18 explanation, 12:51 signal on scope. From an electromechanical alarm clock, I extracted the Lavet Motor and explore it's properties. The motor was invented by the French engineer Marius Lavet in 1936. The mechanism is a stepper motor that gets triggered once a second by an electromagnetic field generated by a coil. A quartz and a frequency divider are responsible for the 1Hz electric pulses. We see the motor spinning, learn about the principle of the mechanism and see the signal on a scope. Also check wikipedia en.wikipedia.org/wiki/Lavet-type_stepping_motor
Interesting. Such an elegant solution. I always thought these devices used a solenoid actuated pawl to push a ratchet wheel. This is a much more durable, reliable and wear resistant mechanism than what I imagined being used.
Super informative! Showing the signal on the scope was great! The very short pulses of electricity allow small battery to last a long time. I would make one correction: The one pulse per second changes direction every second, and so the full cycle on the Lavet motor takes 2 seconds, and it is 0.5 Hz frequency, and not 1 Hz.
Potti interesting video and explanation of an analog alarm clock. You are a good teacher I appreciate learning about things I basically take for granted.
that was very cool, its amazing how they made that clock. its amazing how they figured out how to do all that with wires and things. old analog devices are very neat
Very nice video Potti, I really liked it and your explanations :D. A workmate once brought me a timer clock with such a motor, but I couldn't fix it for her ...at least I know now how it works :). Very nice hehe, you have an old Hameg 😃👍 (does it have the component tester too, as some of them had?). I havn't used my scopes for a very long time 🙄. The little metal thing (the Quartz) is called a crystal, it should be a 32768Hz clock crystal which is divided down (you can divide a couple times by 2 until it reaches 1 Hz). Keep up making such cool videos beside picking :). 😊👋🦊
Thanks mate, glad you liked it. I bought this hameg more than thirty years ago but it still works fine. It has a component tester which I have never used. The frequency of the Quarz should be 2^15 the first power of two over what humans can hear. So cool...
You can improve the accuracy of the clock by replacing the quartz crystal with a crystal from Citizen Watch Company (same size, same package, through hole) with higher initial accuracy, lower temperature drift, and better aging. The motor driver H-Bridge is part of the control IC circuitry. I think the descrete transistor is for the Piezo alarm transducer.
I saw it mentioned a few times, but Ill throw in my two cents too because why not... 3:00 its true "quartz crystal" would get the point across, more exactly its a "crystal oscillator". However, even simply "crystal" would do in just about any conversation, colloquially casual through technical and otherwise. For the uninitiated: The quartz crystal being the bit inside the crystal oscillator that is effectively shaped into a tuning fork (not literally but the same effect) so that it resonates very strongly at the given frequency. A circuit utilizing them would 'flick' the crystal at start up which thanks to the piezoelectric effect (deform crystal make pixies angry) sets the thing jiggling, and it naturally settles into the design frequency giving a resonant return voltage peak much higher than 'normal'. There are better manufactured oscillators which 'tick' more precisely, there are ones that will monitor the crystal chamber temp and output a correction signal (it sounds fancy, but its pretty much just a thermocouple, really simple electronically speaking) to compensate for thermal effects like expansion and contraction of the crystal itself (if it changes shape, it changes resonance. In some application that REALLY matters....A LOT), and then there are SUUUUUPER cool temperature compensated, oven controlled, crystal oscillators!!! These things not only monitor the internal temp, but also contain a heater (again, sounds fancy, but its just a resistor. Still super cool though....er, hot....you know what I mean....) such that the crystal can be actively thermally controlled to resonate exactly where the designer wants it to resonate! Beyond that you pretty much have to start looking into atomic based clock sources if you want higher precision......Luckily, GPS radios are pretty cheap and Network Time Protocol is a thing, and apparently rubidium standards arent impossible to find nor incredibly expensive if you know where to look....so....yeah. Anyhoozle, I totally stopped 3 min in to blurb that. Loving the video so far, mate!
I didn't know it was called a Lavet motor ! I always wondered how the rotor rotated in only one direction, now I know :o) And yes, the timing component is just called a 'quartz crystal' in english, usually in a clock they oscillate at 32768 Hz and divide down to 1 Hz from there, as you said. I think some older clocks the crystal runs at a lower frequency than 32768 though. (I have an ultrasonic 'bat detector' which can hear these 32768 Hz clock crystals vibrating through the clock case - which is nice - though it is _very_ quiet :o) ) Interesting to see just how short the motor coil pulses are too - on an analogue Hameg 'scope too - thumbs up for analogue !
Thanks, the scope is a leftover from my electrics area. I'm glad that I figured out how it works. I was buffed when I saw it the first time. The frequency is just twice as big as what humans can hear.
I haven't gone through all your comments to check, so forgive if someone else noticed the oscilloscope time base red centre adjust is pointing to the right, which is for magnifying the preset divisions, my older Hameg 203 doesn't have the 'cal' label below. So the 30mS pulse is probably a bit shorter.
Nice video. Interesting to see it actually working like that. I did have to rewind it a couple times just to see if you were saying "clock" or "lock". Lol maybe i just keep wanting to hear lock. Anyway nice video!
There's a variation of this motor where you can feed it with 50 or 60 Hz creating a synchronous motor useful for time counters. However my experience is that it might start again backwards if it stops with the rotor at the wrong position. Something that might happen when you have a mechanical counter that's in the process of doing a rollover when it stops.
I fixed a broken motor coil on the movement of an old Linden kitchen clock a while back. I know I could had bought a new movement for around US$6-7 but this movement was better quality than those found in most newer quartz clocks.
@@douro20 Lucky you. I'm forced to wind a new coil for an Italian Boselli flip clock, which has a rather large Lavet-type motor in it (the original coil is missing). 11,750 turns of fine wire are needed. I wonder if I'll pull it off without a professional coil winding machine.
I think it was very interesting Potti. When I was a kid I tore everything apart to see how it worked. Got my butt kicked plenty for it too! LOL But I think people in locksport have mechanical minds. 👍👍👍👍🧡
You get into a little of everything! Did you know that a lot of old clocks that have luminescent hands (so can tell the time in the dark) are slightly radioactive.?
so cool that a crystal can be a perfect 32768 value, and it can be devided by 2 all the way down to 1. the transistor between the output gate of the cob and the coil protect the cob from the reverse spikes coming from the coil fighting back to keep its magnetic field, and the low base emitter current is also better for the cob.
What is the ic that is sending pulses to the coil? I haooened to take one apart today and while its nearly similar the ic on my pcb has that stupid ootting compound over it. However, the circuit looks simple enough the crystal is powered from the aa battery resonating a signal to an ic that appears to be functioning as an amplifier allowing the full 1.5v to oower the coil in short bursts but i cannot gain access to the ic without possibly damaging it.
The transistor is only for the beeper part.. it beeps every time the signal starts and stops from the positive then negative applied voltage to turn the rotor, so beeps 4 times a second and the delay is a product of the circuit and transistor switching states..
Same goes for wrist watches , they're just a lot smaller and , heavier a lot to reassemble. :) Main thing aka "heart" of any quartz watches is the part at 3:07 , there's inside tiny quartz "fork" (can't recall exact name in english and , I'm lazy to google it) , which is perfect in Bulova Accutron II mechanisms and oscilates exactly 262KHz. :) Now , the circuitry and motor step it down do 1Hz which is equivalent of 1 movement in this case. :) I wont get into entire process here , as it can be very lenghty comment , but , I did watchmaking as a hobby. :) Older quartz watches from 1940's to 1960's have oscilating element quite big and can be heard as buzzing. :) Then , Bulova himself have changed them a lot to what we know they look like today. :) City and every public installment ( big , public) of these is of size like shoe box. :) Edit: Yes , it does get amplified as output is very low from quartz element , so , this transistor should be the NPN one. :) Voltage gets amplified , so that motor can do its part while frequency gets lowered down. :)
It was joy. I have similar Kienzle clock that still works today. :) And is a bit older than me. :) I remember when I was a kid incorrectly reading it as "Kinezle". 😂 It's sturdy clock , it survived numerous fist punches as the sound they make would scare the s*#t out of person. 😂 They also ticked , but with no movement when battery was nearly flat , seconds hand would just tilt in place. :) Yeah , newer ones oscilate at much higher frequencies and sometimes have two oscilating elements that do not oscilate at same frequency to avoid interference. These types of mechanisms can be found in chronograph type wrist watches. :) Or Casio G-Shock series , as I am most familiar with these. :)
That's a fun thing to do. I was once kept waiting in a scruffy meeting room at a business partner's for much too long. I took my revenge by making their cheapie IKEA clock run counter-clockwise.
That gear ⚙️ is magnetic 🧲, the one ☝️ ya were showing us through the broken 😞 motor housing. Electrical impulses are sent from the copper 👮♀️ coil, to the magnetic 🧲 gear ⚙️, making it turn, and the clock 🕰️ keep time. Quartz clock ⏰ motors are a complicated concept to digest (knowing how they work). Your friend, Jeff.
they work the same, but they divide the clock 8x less (so they get 8 pulses per second) and are geared so that they move 8x less. The 8x is by ear, it could be 4x or 16x but you get the idea.
@@sail4life You've got a good ear on you, 8 times a second it is. Also, you could record a video of the second hand, play it back slo-mo and count the steps.
The electronics generate eight pulses a second instead of the one per second. Likewise, it takes eight half-rotations of the rotor to advance the second hand one second. That gives the impression of continuous motion. There's a rapid ticking noise, but it's less pronounced.
Hi How can I Make 24 Hours And 45 Minutes Clocks Measurement Let's Say For Other Planets well Actually My Circadian Rhythm Is 24 Hours and about 48 Minutes on Average I have Delayed Sleep Phase Disorder Dspd Non-24 Hours some People Call Me Martians I Know It Is Frustrating To Wake Up 45 Minutes Later Every Day But I accepted This As a 32-year-Old i am interested To Make Clock That Tracks My Body clock Do You Know Any Html Or JavaScript Or Any Other Codes To make or Is there any Html Codes Of Martian Time That I Can change It From 39 Minutes To 45-48 Minutes? If Not How Can I Slow Down A Quartz Clock To Run little Slower let's say Capacitor or Resistors 3% Percent Slower But Not Pendulum Clocks Cuz That's The Easiest One Thank You So Much, Sir I hope You Have Some Solutions For Me
You'll have to replace the onboard electronics with your own. An Arduino would do it. I've made 24-hour analog clocks with simple 74HC00-series chips, but your 24:45-hour clock is easier to tackle with a microcontroller.
1:40 demonstration, 6:18 explanation, 12:51 signal on scope.
From an electromechanical alarm clock, I extracted the Lavet Motor and explore it's properties. The motor was invented by the French engineer Marius Lavet in 1936. The mechanism is a stepper motor that gets triggered once a second by an electromagnetic field generated by a coil. A quartz and a frequency divider are responsible for the 1Hz electric pulses. We see the motor spinning, learn about the principle of the mechanism and see the signal on a scope.
Also check wikipedia en.wikipedia.org/wiki/Lavet-type_stepping_motor
Well not relly for me but very cool to learn a bit tho and the package should get to you sometime next week i Hope so
Nonetheless, thanks mate - sometimes I post about topics out of the usual lock area. Will send your package probably next week.
@@Potti314 and that is just fine it is interresting to see other stuff too, and my package?
Interesting. Such an elegant solution. I always thought these devices used a solenoid actuated pawl to push a ratchet wheel. This is a much more durable, reliable and wear resistant mechanism than what I imagined being used.
Thank you for your demonstration of how a quartz clock works
Thank you, finally a video that fully explains a quarts clock
Thank you for explanation on how levet-type stepping motor work.
Super informative! Showing the signal on the scope was great! The very short pulses of electricity allow small battery to last a long time.
I would make one correction: The one pulse per second changes direction every second, and so the full cycle on the Lavet motor takes 2 seconds, and it is 0.5 Hz frequency, and not 1 Hz.
Thanks, Potti for the interesting video. Explanation of the heart of the quartz clock very well explained.
Glad you enjoyed it.
Very clear explanation on the working on quartz Clock Levat Motor!! thanks you!!
You are welcome.
0:00 wow That clock face is so pretty!! Looks like a "Chevrolet Opala" Dashboard clock design. Nice video
Potti interesting video and explanation of an analog alarm clock. You are a good teacher I appreciate learning about things I basically take for granted.
Thanks for stopping by. Glad you had fun watching.
Nice, and thanks for breaking it down. I had no idea, you see those everywhere but never realized how ingenious they were!
It's pretty cool how it works. Glad I dug into it.
that was very cool, its amazing how they made that clock. its amazing how they figured out how to do all that with wires and things. old analog devices are very neat
Cheers. Took me a while to understand how it all works. But yes, to invent it there's a lot to it.
Very nice video Potti, I really liked it and your explanations :D. A workmate once brought me a timer clock with such a motor, but I couldn't fix it for her ...at least I know now how it works :). Very nice hehe, you have an old Hameg 😃👍 (does it have the component tester too, as some of them had?). I havn't used my scopes for a very long time 🙄. The little metal thing (the Quartz) is called a crystal, it should be a 32768Hz clock crystal which is divided down (you can divide a couple times by 2 until it reaches 1 Hz). Keep up making such cool videos beside picking :). 😊👋🦊
Thanks mate, glad you liked it. I bought this hameg more than thirty years ago but it still works fine. It has a component tester which I have never used. The frequency of the Quarz should be 2^15 the first power of two over what humans can hear. So cool...
Excelente explicação e didática. 👍🏽🇧🇷😁
That's a beautiful and detailed explanation of how it works. Thanks brother for this video.. From India!
Thanks a lot for your motivating comment.
You can improve the accuracy of the clock by replacing the quartz crystal with a crystal from Citizen Watch Company (same size, same package, through hole) with higher initial accuracy, lower temperature drift, and better aging. The motor driver H-Bridge is part of the control IC circuitry. I think the descrete transistor is for the Piezo alarm transducer.
I saw it mentioned a few times, but Ill throw in my two cents too because why not...
3:00 its true "quartz crystal" would get the point across, more exactly its a "crystal oscillator". However, even simply "crystal" would do in just about any conversation, colloquially casual through technical and otherwise.
For the uninitiated: The quartz crystal being the bit inside the crystal oscillator that is effectively shaped into a tuning fork (not literally but the same effect) so that it resonates very strongly at the given frequency. A circuit utilizing them would 'flick' the crystal at start up which thanks to the piezoelectric effect (deform crystal make pixies angry) sets the thing jiggling, and it naturally settles into the design frequency giving a resonant return voltage peak much higher than 'normal'. There are better manufactured oscillators which 'tick' more precisely, there are ones that will monitor the crystal chamber temp and output a correction signal (it sounds fancy, but its pretty much just a thermocouple, really simple electronically speaking) to compensate for thermal effects like expansion and contraction of the crystal itself (if it changes shape, it changes resonance. In some application that REALLY matters....A LOT), and then there are SUUUUUPER cool temperature compensated, oven controlled, crystal oscillators!!! These things not only monitor the internal temp, but also contain a heater (again, sounds fancy, but its just a resistor. Still super cool though....er, hot....you know what I mean....) such that the crystal can be actively thermally controlled to resonate exactly where the designer wants it to resonate! Beyond that you pretty much have to start looking into atomic based clock sources if you want higher precision......Luckily, GPS radios are pretty cheap and Network Time Protocol is a thing, and apparently rubidium standards arent impossible to find nor incredibly expensive if you know where to look....so....yeah.
Anyhoozle, I totally stopped 3 min in to blurb that. Loving the video so far, mate!
I didn't know it was called a Lavet motor ! I always wondered how the rotor rotated in only one direction, now I know :o) And yes, the timing component is just called a 'quartz crystal' in english, usually in a clock they oscillate at 32768 Hz and divide down to 1 Hz from there, as you said. I think some older clocks the crystal runs at a lower frequency than 32768 though.
(I have an ultrasonic 'bat detector' which can hear these 32768 Hz clock crystals vibrating through the clock case - which is nice - though it is _very_ quiet :o) )
Interesting to see just how short the motor coil pulses are too - on an analogue Hameg 'scope too - thumbs up for analogue !
Thanks, the scope is a leftover from my electrics area. I'm glad that I figured out how it works. I was buffed when I saw it the first time. The frequency is just twice as big as what humans can hear.
Very good explanation 👍
Man of many talents, love the variety on your vids
Thanks - glad you enjoyed watching.
I haven't gone through all your comments to check, so forgive if someone else noticed the oscilloscope time base red centre adjust is pointing to the right, which is for magnifying the preset divisions, my older Hameg 203 doesn't have the 'cal' label below. So the 30mS pulse is probably a bit shorter.
thanks alot, this allowed me to repair an alarm clock
Nice video. Interesting to see it actually working like that. I did have to rewind it a couple times just to see if you were saying "clock" or "lock". Lol maybe i just keep wanting to hear lock. Anyway nice video!
Have misspoken it once and had to redo a part of the video. I'm just not used to speak about clocks ;-)
There's a variation of this motor where you can feed it with 50 or 60 Hz creating a synchronous motor useful for time counters. However my experience is that it might start again backwards if it stops with the rotor at the wrong position. Something that might happen when you have a mechanical counter that's in the process of doing a rollover when it stops.
I fixed a broken motor coil on the movement of an old Linden kitchen clock a while back. I know I could had bought a new movement for around US$6-7 but this movement was better quality than those found in most newer quartz clocks.
Great to read that someone fixes such things :-)
Interesting. Did you wind a new coil?
@@luvnotvor No, I found the end which broke off and soldered a thin wire to it. It was very close to the end of the winding.
@@douro20 Lucky you. I'm forced to wind a new coil for an Italian Boselli flip clock, which has a rather large Lavet-type motor in it (the original coil is missing). 11,750 turns of fine wire are needed. I wonder if I'll pull it off without a professional coil winding machine.
I think it was very interesting Potti. When I was a kid I tore everything apart to see how it worked. Got my butt kicked plenty for it too! LOL But I think people in locksport have mechanical minds. 👍👍👍👍🧡
Haha, taking things apart is fun and education ;-) Thanks for stopping by.
You get into a little of everything! Did you know that a lot of old clocks that have luminescent hands (so can tell the time in the dark) are slightly radioactive.?
Yes have heard about that radioactive glowing. Guess my clock is not that old however. Thanks for tuning in.
so cool that a crystal can be a perfect 32768 value, and it can be devided by 2 all the way down to 1. the transistor between the output gate of the cob and the coil protect the cob from the reverse spikes coming from the coil fighting back to keep its magnetic field, and the low base emitter current is also better for the cob.
Ah, thanks for pointing that out. Makes perfect sense to me.
Thank you!! Is it the same principal for wristwatches with quartz movement?
What is the ic that is sending pulses to the coil? I haooened to take one apart today and while its nearly similar the ic on my pcb has that stupid ootting compound over it. However, the circuit looks simple enough the crystal is powered from the aa battery resonating a signal to an ic that appears to be functioning as an amplifier allowing the full 1.5v to oower the coil in short bursts but i cannot gain access to the ic without possibly damaging it.
The transistor is only for the beeper part.. it beeps every time the signal starts and stops from the positive then negative applied voltage to turn the rotor, so beeps 4 times a second and the delay is a product of the circuit and transistor switching states..
Nice.
Same goes for wrist watches , they're just a lot smaller and , heavier a lot to reassemble. :) Main thing aka "heart" of any quartz watches is the part at 3:07 , there's inside tiny quartz "fork" (can't recall exact name in english and , I'm lazy to google it) , which is perfect in Bulova Accutron II mechanisms and oscilates exactly 262KHz. :) Now , the circuitry and motor step it down do 1Hz which is equivalent of 1 movement in this case. :) I wont get into entire process here , as it can be very lenghty comment , but , I did watchmaking as a hobby. :) Older quartz watches from 1940's to 1960's have oscilating element quite big and can be heard as buzzing. :) Then , Bulova himself have changed them a lot to what we know they look like today. :)
City and every public installment ( big , public) of these is of size like shoe box. :)
Edit: Yes , it does get amplified as output is very low from quartz element , so , this transistor should be the NPN one. :) Voltage gets amplified , so that motor can do its part while frequency gets lowered down. :)
Thanks for the info and for watching. Will measure the frequency as I have heard that 2^15Hz is used nowadays. It's such a cool mechanism.
It was joy. I have similar Kienzle clock that still works today. :) And is a bit older than me. :) I remember when I was a kid incorrectly reading it as "Kinezle". 😂 It's sturdy clock , it survived numerous fist punches as the sound they make would scare the s*#t out of person. 😂 They also ticked , but with no movement when battery was nearly flat , seconds hand would just tilt in place. :) Yeah , newer ones oscilate at much higher frequencies and sometimes have two oscilating elements that do not oscilate at same frequency to avoid interference. These types of mechanisms can be found in chronograph type wrist watches. :) Or Casio G-Shock series , as I am most familiar with these. :)
Please let me know if it is possible to change direction of the rotor! Thanx Harry
Why the hell would you want to do that?
Is it possible to make electric power generator by this motor setup.
Good job
Very good 👍 Thanks 🙏🙏
If you flip the "U" shaped magnet over, the clock will run backwards.
I didn't hear if you mentioned it or not, but the crystal is 32,768 Hz, with a 15 step counter.
Thanks for watching and commenting. I also read about the frequency, just the first power of two that's over humans abilities to hear.
That's a fun thing to do. I was once kept waiting in a scruffy meeting room at a business partner's for much too long. I took my revenge by making their cheapie IKEA clock run counter-clockwise.
@@luvnotvor part of the counterculture.
I thought reversing the coil connection to the circuit board will do it.
Hook a speaker to the coil wires and you can hear the pulse.
Coll idea :-)
That gear ⚙️ is magnetic 🧲, the one ☝️ ya were showing us through the broken 😞 motor housing. Electrical impulses are sent from the copper 👮♀️ coil, to the magnetic 🧲 gear ⚙️, making it turn, and the clock 🕰️ keep time. Quartz clock ⏰ motors are a complicated concept to digest (knowing how they work). Your friend, Jeff.
Sir that small gear was keep on jumping off So I put little fevikwik now it's(gear) not moving. What to do sir???? Pls guide me 🥵😩😱😭😓😓😩🥵
Does coil have polarity
Well done! ✔
try flipping the coil around and the rotor runs in reverse.
Ok
Cool, thanks!
شرح رائع
how does the alarm work tho?
Well Done
If there are two coil, the movement will be hi beat?
Can you explain how sweep quartz movement works?
No idea what a sweep quartz movement is.
@@Potti314 its like normal quartz but higher beat
they work the same, but they divide the clock 8x less (so they get 8 pulses per second) and are geared so that they move 8x less. The 8x is by ear, it could be 4x or 16x but you get the idea.
@@sail4life You've got a good ear on you, 8 times a second it is. Also, you could record a video of the second hand, play it back slo-mo and count the steps.
Some quartz clocks shows continuously sweeping moment without ticking noise, how?
The electronics generate eight pulses a second instead of the one per second. Likewise, it takes eight half-rotations of the rotor to advance the second hand one second. That gives the impression of continuous motion. There's a rapid ticking noise, but it's less pronounced.
@@luvnotvor Thank you!
Very nice
Thanks.
Thank you
Cheers :-)
Oh, an analog oscilloscope. I haven't seen that for a long time. xD
Haha, that analog scope is the only one I have and it does work OK :-)
A strange video but still very cool my friend. 🍺😎
Haha, strange as a clock and no lock?
@@Potti314 yes but I still find it interesting with my limited electronics knowledge. ✌😎
فيديو جيد
Thanks a lot🙏💕🙏💕🙏💕🙏💕
You're welcome.
Cut the second hand short and you save the battery
Hi
How can I Make
24 Hours And 45 Minutes Clocks Measurement
Let's Say For Other Planets
well Actually My Circadian Rhythm Is 24 Hours and about 48 Minutes on Average
I have Delayed Sleep Phase Disorder
Dspd Non-24 Hours
some People Call Me Martians
I Know It Is Frustrating To Wake Up 45 Minutes Later Every Day
But I accepted This As a 32-year-Old
i am interested To Make Clock That Tracks My Body clock
Do You Know Any Html Or JavaScript Or Any Other Codes To make
or Is there any Html Codes Of Martian Time
That I Can change It From 39 Minutes To 45-48 Minutes?
If Not
How Can I Slow Down A Quartz Clock To Run little Slower
let's say Capacitor or Resistors
3% Percent Slower
But Not Pendulum Clocks
Cuz That's The Easiest One
Thank You So Much, Sir
I hope You Have Some Solutions For Me
You'll have to replace the onboard electronics with your own. An Arduino would do it. I've made 24-hour analog clocks with simple 74HC00-series chips, but your 24:45-hour clock is easier to tackle with a microcontroller.
Pls upload /send wiring diagram
Sorry I cannot find it anymore.
:D