How fast can a Quartz Clock spin?

[@vaishakhmonti]

Fantastic effort. Loved the video and your walk through. Great that you find the time to do this. Well done.

[@tedtw]

Pulse width might need to be wider or narrower at higher frequencies (i.e. duty cycle) to compensate for magnetic field rise/fall times. Also, a ramp-up to speed would help overcome inertia. This is commonly used for stepper motors, and in reality this is a dirt-simple stepper motor. All these things are easily accomplished in software.

[@dbaznr]

You not even need the bridge. You can drive directly the coil with Arduino's ports. Arduino's ports can support about 20mA, pretty enough for this coil. Take 2 ports (es. D11, D12) as A and B, and repeat the pattern {A,B} = (0,0),delayOFF, (1,0),delayON, (0,0),delayOFF, (0,1),delayON... If you want to protect the ports from eventual back-EMF, put 1K Ohm resistors before the coil wires.

[@erichleonhard3188]

Thank you, Robert!! For two beautifully explained 'mysteries'!! I'm here from your other video where you have dissected and explained a quartz clock. I also asked a question there, echoing others, who wanted to know how to halve the 1 second frequency of the motor, to enable a single hand revolution to cover 24 hours. I am amazed that there seems to be much greater interest in speeding up the clock.....visually more dramatic, I expect. So now I have two requests: a) could you give details of how to slow it down to half speed accurately and b) dissect and explain the working of a quartz clock with a sweep second movement.

[@michaelantony6395]

H-Bridge beautifully explained

[@marshaul]

I would have been curious to see you try _increasing_ the pulse duty cycle and seeing how far you could lower the delay, or at least how it would affect the movement at different speeds.

[@rivkiebenedikt2924]

This video is amazing!exactly what I was looking for. Is the Arduino code still available anywhere?

[@gregh7457]

Nice video. I've always wanted to make an analog clock know what time the hands are displaying by using a rotary encoder. One problem is many of the clock gears are too small to add an encoder wheel.

[@vivchawda]

guess with the cover closed & drive gear pivoted, it could go little faster. can it drive the assembled gear train at top speed?

[@Jtoksa2]

I took apart one such mechanism and it actually cycles the solenoid though four different states, not two, so that between the states where current flows in each direction, there is a stage where no current flows (low,low -> low,high -> high,high -> high,low->...).

[@Jimnymudhunter]

Up the halt by the MS and you can go even faster! Also you need the other gears on it to stop that rotation switch it needs some mass to keep it going the way you want it it.. also try running the H bridge on 3.3v not 5v.. it may be too much power peaking out the transistors.. PS. what soldering iron is that??

[@templebrown7179]

You really didn't need to remove anything from the clock except the crystal. You can then just input a clock signal greater than 32khz to speed up the clock. A 555 timer could easily get you to 30rpm. A lot of your direction changing is just due to wobble with your gears not being held in well.

[@alaas8141]

Thanks alot man u saved me! Ruined mum's clock n thought that's that end of it but I've just fixed it!

[@cphank151]

Have you tried increasing the on time to perhaps 10mS? This should allow more on time for driving the coil to saturation if it doesn't saturate in 5ms. This may accelerate the rotor faster and allow 120mS or less of off time.

[@gabrielv.4358]

I Expected to see it mounted and working

[@berryj.greene7090]

A very clear interesting & instructive video. Thanks. Note no upper pivot for armature. You really do need that to centre it. If I were soldering this up those fine copper wires to the coil would be sure to break off! That wire is so thin it needs more support than this. You must have been super lucky that didn't happen. Please may I ask you two Q's ? 1) What sort of logic in the original clock, can operate at 1.5V ? {Battery} 2) Please may I have the redundant clock PCB for my own clock repair ? Sincerely Berry JG

[@Origoangelohrol322]

I have tried to connect a 50 Hz voltage with a proper value to the solenoid. The whole mechanism was assembled, and it required a little push of the second hand to start spinning. It was also spinning equally good in both directions which varies a little bit the operating principle of the lavet motor. But it was running good at 25 times higher than the normal speed. Should try it with a signal gen at even higher frequencies.

[@en2oh]

you need to reverse the current flow in the solenoid to get the stepper to step. If you apply a true, 50hz AC signal, this is automatic, even though cross over between +ve and -ve voltage can't be controlled.... however, doing the same thing with an h-bridge and you can certainly drive the solenoid beyond what the video suggests.

[@dcordel2998]

Sir, your video is good but your circuit is hidden in certain parts by the writing on the screen which spoils your demo.

[@Poonyas]

Hi Robert, Great to see your video blogs which do explain a lot so even electronic dummies like me can understand. I am looking for a quartz mechanism that would spin only once per year by modifying the electronics instead of using 365 teeth. I though of an adjustable oscillator like ’50Hz～6kHz NE555 Square Wave Output Module Oscillator Pulse Generator Adjustable’ that I found online. As I am not into electronics too much I am probably not able to make it work anyway and would like to ask you if you have an idea how it could be easily done to have a quartz module slowed down by 265. Thank you 😉

[@HifiCentret]

Instead of soldering to the thin coil wires. Just cut the PCB tracks and solder on the PCB. A lot easier and gives better physical stability. If done properly you can even repair the PCB again. I've done that with a couple of clocks. One to be driven by custom DS32KHz circuitry. One to be driven by the electronics taken from a vintage radio controlled aftermarket clock movement from before hand where self-aligning and hey presto The clock is radio controlled but hand and everything can be kept original and even reversed if I want to.

[@HifiCentret]

Btw. With the right controller logic - speed adapted - you can get pretty amazing speeds on those motors. I don't know where you live but in Europe we have the DCF transmitter and if you want a radio controlled movement fitting "euro hands" - typically for new German clock and vintage European clocks of many brands - if you want to preserve the original hands unaltered (you can even keep original movement to reverse is possible) your only option is the Hechinger W70 RC clock movement. It's a one motor movement (many RC today is two motors) with step each second. The amazing thing is when it adjusts itself - which it even in worse case granted good radio reception only takes 15 minutes. 3 minutes for reception - 12 for setting. The second hand literally races around at a speed of approx. one revolution pr. second. A have seen a few other one motor RC clocks before including the before mentioned but that is pretty slow using about 5-6 minutes to gain one hour - which the Hechinger does in only minute.

[@en2oh]

in the case of the atomic clock, how did you detect home position for the hands?

[@majeedkoya1759]

Hello Robert can you please tell me what is the normal resistance of the solenoid coil

[@holgerschnarre2052]

Try more and smaller impulses for one turn instead of one Impulse. You can reach higher rotation speeds. -> asservicement quartz

[@danieli2570]

very well done video man!

[@ranacse05]

Hello, excellent work . I’m trying to recreate it. Can I get the circuit diagram?

[@aleksandar7393]

Have you tried to increase Halt time a bit to let say 6 - 7ms but decrease On Time further, I think that may work? Sorry my bad, just saw it is other way around Delay time is larger ....

[@colinstamp9053]

You should be able to get it to spin much faster than this. The timings you've chosen assume that the rotor must stop at the end of each cycle. This needn't be the case. You should find bands of frequencies higher up the range where the rotor is still moving when the next pulse comes at just the right time to kick it further on. You'd need the rest of the gear-train and the hands in place to get the right mechanical properties. The second hand would effectively be a flywheel.

[@cphank151]

I doubt the second hand would be a very good flywheel because it is spinning at about 1/30th the motor speed. I suspect highest speed would be obtained with no load and the permanent magnet rotor behaving as the flywheel. Modifying the second hand to increase its weight (angular inertia) without ruining it's balance may help its behaving as a flywheel.

[@bobdurk5180]

I was able to get the second hand to do a rotation in 3 seconds reliably. I did with other code achieve the 6 second rotation I was looking for. Now I have to figure out how to get this gimmick clock to reset to 12:00 position, start on a button press, run for 6 real minutes ( minute hand will travel 1 full revolution) and stop. cycle will repeat as needed. The timing is so critical, I spent a long time trying small changes and still can't find the sweet spot for running 6x faster than normal with a Lavat clock mechanism. I was able to use a stepper motor to do all this reliably, so I am at a point where I need to decide which way to proceed. I like the Lavat method, as clocks are cheap to buy and hack.

[@majeedkoya1759]

My old citizen clock was dead. I found its solenoid coil was open. I made coil and clock working. The problem it's battery draining very fast .lasting only 4 month.may be my coil is not sufficient. Please give me what is the normal coil resistance..thanks

[@chazM6116]

How fast can a Quartz Clock spin? You did not do that as you removed the Quartz and you only have the solenoid .....

[@supercables251]

Can't find the part where he spins the clock. I can't even find the clock anywhere in the video, just the motor.

[@castillelarkin]

It would have been great to see the hands spin. Maybe it would have affected the top speed too.

[@ethendixon4612]

Where can I buy one of those little lavet stepper motors?

[@binglear]

Very interesting, Thanks.

[@jaanov6094]

thank you

[@phiestrada5156]

This can mimick the sweep seconds hand of automatic watches

[@DudeBoerGaming]

If you use different transistors you will be able to increase the speed.

[@RobertMassaioli]

You may be right. I assumed that the limiting factor would be the physical resistance to spin of the pinion gear. However, it may simply have been that my transistors could not switch fast enough. Though I still do find that idea surprising: I would have thought that even these transistors should be able to switch hundreds or even thousands of times a second (I'll double check that now :) ). Looking at your experience though I suspect you may know something I don't. Can you please post more of your thinking here so that others can learn from it too?

[@hamideddaifi5615]

thanks profesor,,, amazing

[@Esparzamx]

ok, so just to be sure, the PCB that you disconnected is only one of those H bridges and a chip that controls the input of the quartz right???

[@Esparzamx]

Smartphone David thanks for corroborating, always nice to remember that not all youtube comments are mean

[@Mieczymir]

Please add diagram for transistor conection

[@mohamednuwais]

hi is there any posibilty get the sketch from you

[@joecastelli3998]

Excellent !!!! thank you

[@shanmughamr6262]

Hey thankS a tonne... that is what called "crystal clear explanation"....thank u mike

[@nasirahsan786]

How to adjust slow moving or correct time + /--

[@jozefnovak7750]

Super.

[@johngoldsmith4844]

All the clocks I've dismantled - and that's quite a few - did not use an H bridge. They simply connected one end of the coil to 0V and the other was driven via a capacitor from the electronic drive. Drive out 'high' sends current through the C and coil one way. Drive out 'low' allows the current back the other way. Result is reversing current in the coil, and no standing current even though the drive out stays high or low, as the C blocks it. Then to test how fast it will drive just use a square wave signal generator, such as a 555, with a tweaker pot instead of all that hassle with programming an arduino. Incidentally the directional control of the motor is achieved by clever shaping of the pole pieces. You can't change it.

[@en2oh]

actually, the current direction reverses to effect the stepping action. The IC that is typically sealed in a dab of epoxy does contain an h-bridge. you can check out NXP.com PCA200x OR hackaday.com/2018/06/07/dive-inside-this-old-quartz-watch/ (or both, if you're really interested). The clever bit in the integrated poles is the asymmetry that results in a preferred clockwise rotation, as you mentioned in your comment.

[@MardukUnderscoreNinetySix]

Dude that white noise tho

[@mrryc1]

Could you please let me know what NPN transistor you were using? Are the resistant-value connecting to the 4 bases critical? and what the resistor value? Appreciate. 🙂

[@en2oh]

what do you mean by (2dp)? The test mode (acceleration mode - used to free up slowly running gear train) has a 30hz frequency in the quartz watch movements

[@mostafazangiabadi6834]

How low can a Quartz Clock spin?

[@DudeBoerGaming]

As long as you provide it power

[@mhingankar2]

You used Arduino. That's not the deal. Make it without Arduino. And you didn't show circuit diagram.

[@vanhetgoor]

I am sorry, your prediction was wrong. It became 2018 when I saw this movie.

[@sawajiri100]

Transistor as function switch Base -----------low voltages input signal Emitter--------Disallow voltages or allow voltages Collector-----Disallow voltages or allow voltages 0 volts in Base Transistor is OFF or disallow voltages 0.5 volts or 1 volts in Bse Transistor is ON or allow voltages

[@leef_me8112]

You didn't really accomplish the task and answer the question. During your experiments you had various results. But during you experiments you were only driving the first gear, not the fully clock movement. 15:26 little blob is moving clockwise, 1 second per revolution 16:08 little blob is moving counter-clockwise, 1/2 second per revolution **** 16:25 little blob is moving counter-clockwise, 1/4 second per revolution **** 17:50 delay time 160ms, little blob is moving clockwise

[@gabrielv.4358]

Incrivel

[@momatomic]

I came across this video because I woke up at 4AM, checked the time on my little quartz clock that I've had for over ten years. The second hand was spinning backwards wildly at over one revolution per second. Each revolution backed it up by a minute. I grabbed my cell phone and got two short video clips of it doing this. It was weird. I didn't do anything to the clock to make it do this, and I didn't do anything to make it start going forward again. What the heck? Maybe I can post the video...anyone interested? Anyone have a clue?

[@en2oh]

do you have a "radio controlled clock" or a so-called "Atomic clock"?

[@lionelwilliamzhang1534]

I hake clock

[@altexlan415]

rubbish?