Classic simple clock pendulum circuit 

I can't decide if this is a good circuit or not. I keep swinging back and forth on this.

I'd love to see you rig up a simple pendulum and get this working, then hang a scope off the coil to see the waveform :D Then disconnect that damping capacitor and see the effect it has

Very impressive how you zoomed out just the right amount where the end pop-ups fit precisely. 😎

Clive packing to go on a work trip looks like he is moving by the time he puts all the cameras and everything in there, lmao. Thanks for the video Clive

Used to be a company (Kundo) made clock in the 60s with this type of mechanism, although with germanium transistors, OC71 or similar. Must have looked like magic at the time.

I just picked up a 70's Smith's carriage clock that uses this sort of circuit. In that case it isn't a pendulum but a spinning magnet attached to a balance wheel and escapement. I usually prefer fully mechanical clocks, although I do like the accuracy of quartz I try to avoid having too many quartz about the house. This clock I just got surprised me as it wasn't fully mechanical and certainly not quartz. It also has a lovely tick tock sound too.

Super interesting. It is almost like a tuned pwm or tuned mono stable device where the pulse turns on to suit the swing. Very effective & clever! Thank you for sharing!

Thanks Clive. Thank you for all of the problems you helped me resolve,

Another instance where learn how something functions, that I have always wondered about. Thank you Big Clive.

Greetings Clive! Hope you are well. Yes I have been there too,, A swinging desk ornament of a couple swinging on a swing, there were loads of these knocking about Inthe 80's,, My swing originally had a Similar circuit as you described,, mine was not working,, I further screwed it up trying to get it working,, in the end I used an op amp and home made coil, I even replaced the 2xAA cells with a more convenient lipo cell & usb C charging port lasts about a month until it needs charging, strangely rewarding making the whole thing work after all these years,, You in part inspired the rebuild after I watched your (what could be done with lipo cells from vapes that had been thrown on street,, Thanks dude

Great 👍🏻 little video about clock 🕰️ starters

Thank you Clive

Years ago ( 1970s) there was a animated advertisement display at a Woolworth's store. It had one transistor, one resistor, one capacitor, and the coil. The swing arm had a magnet on it. It would run for months in a old school zinc carbon " D" size battery.

Thanks a million OMHS Clive 👍🇮🇪🙏🏻

Clive. Thanks for the normal but somewhere else video, it's made me realise that the world hasn't gone mad, it's only AvE that's lost it. 😆👍

Coming From you it's very interesting love watching your stuff. Schematic included

You are the Bob Ross of electrical circuits

Thanx again I’ve learnt so much from you Thank you

This looks like a version of the classic Hartley oscillator. The centre tapped coil and 100nf capacitor form a resonant circuit. The larger capacitor and resistor are biasing. It would be interesting to see if the circuit resonates without a pendulum, and at what frequency. If we know the wire thickness, we could estimate the length of wire, number of turns, the inductance then estimate a resonant frequency for the tank circuit.

Brilliant!

What a coincidence, I was at BHI clock museum near Newark yesterday. Apart from The Speaking Clock and Greenwich Mean Time kit I loved the old Master Clock systems from a pendulum master like Pulsinetic and Gents of Lecester I maintained in big factories around Liverpool 50+ yrs ago

Nice little circuit. The coil bobbin looks a lot like one designed for clock mechanisms.

That's a cool circuit.

very simple design

Nice and simple, just like me!

This circuit is similar to the joule thief or the blocking oscillator. As you suggest, the capacitor between base and collector must stop the circuit oscillating at a much higher frequency. The circuit likely operates on the edgy of stability. I have seen examples where the circuit has been used to phase lock a pendulum to a more accurate time signal, either a crystal or a radio time signal. I assume such circuits put a small bias on the pendulum so that it runs slightly slow, or maybe fast I can't really decide which, it must depend on the mode of operation. The circuit just pulls the oscillation into phase with the master time signal. In the example I was shown, the pendulum had an aluminium plate added to the end. This passed through a slot between two coils. When the coils were energised, the pendulum was slowed by induced eddy currents.

I keep hearing coil saturation in different videos, my experience with a current probe and hall sensor shows this not to be the case. Thanks for sharing. Also, i was a little surprised the coil is center tapped, most cases I have seen, the base side coil has many more turns (like the top secret spinning top), it does not have to be, but seems more tuned for efficiency.

Homofaciens built a nice coil winding machine out of a 3d printer .. (which printed the bobbins first and then wound the wire on it.) .. but sewing machine is genius ! 👍

Love your sssssschematics...

In principle it might be neat to look at Bulova's "Accutron" watches, first sold in October 1960, They used use a 360 Hz tuning fork and transistor energised instead of a balance wheel as the timekeeping element, It was guaranteed to be accurate to a minute a month. Broken ones seem to go for as little as 15 quid.

Great to see a youtube presenter considering where all those popups are going to appear at the end of the video, all too often those little windows pop up, obscurring important/intersting details on the main video!!

Very similar to joule thief 😊 your favourite Clive 😅 Mine too 😅😂❤

Haha no way! I was just designing a (much!) larger driver for my hammock auto-swinging. Might take a little bit of an inspiration from this one!

The 100nF cap would damp if it was in parallel with the coil. As it is in series with the coil and the base of the transistor, it will actually decrease the rise time on the transistor switch (i.e. it will increase the frequency)

This is one of those where it would be gret to see this on a multi channel oscilloscope 🤔 one channel for each coil

I'm guessing it'd be in something like those Felix the Cat clocks that were popular oh so many years ago, where the tail swung as the pendulum, and the eyes looked side to side too... :P

Is it weird that I love how Clive pronounces "microfarad?"

I think that was called a 'blocking oscillator' 50 yrs ago, got its name from how a signal was blocked on a radio or something.

That's almost exactly the same circuit used in the battery operated Kit-Cat Klocks. It differs only in the placement of the 1M resistor and it uses a 22uF capacitor and runs off of 3V instead of 1.5V.

I’ve wanted to retrofit my electric kit-kat klock, for decades!

If the resistor's purpose really is to keep the transistor slightly biased on, I think the electrolytic capacitor's leakage current should be enough for that. Though I doubt such weak biasing is necessary at all in this application. Seems to me like the 1M resistor would be better used across BE to minimize Ice between pulses.

Fishing reels are good for winding larger coils. 😉 ✌♥️🇬🇧

Yes, I've learned over the years the simple designs are the best. One or two transistors and a few components other than a tiny crystal driven timer chip. In fact, I used this same principal years ago to accelerate a round magnet to over 150,000 RPMs

I’d love to see the blob chip version with an oscilloscope

Turn the coil through 90deg. Allow the magnet to pass through the coil. This fixes the torque problem twisting the pendulum rod.

It explains why my clock stops before the pendulum does.

Solar powered bobble head toys use this. Kit-Cat clock has similar but was invented 90 years ago and AC powered, converted to battery in 80's.

The 100 nF capacitor is possibly fitted to pass a very brief pulse ( which the 1 M Ω cannot do ! ) ... in some circuits this is called a " speed up capacitor " ... ( ? ) ...... DAVE™ 🛑

Less components less failure! My 1985 panda always work perfectly after 28 years and survive at other 9 cars in family!!

Pendulum circuits? I kind of go back-and-forth on the topic...😉

Very similar to your joule thief circuit you designed Clive.

Hey Big Clive, I'm like a transistor ... although as I get older, it takes MORE than a little "bias" to my "base" to turn me on! ... And the "output" from my "emitter" isn't what it used to be! 😂

Get well soon

It's a joule theif in disguise 👍👍

Clive, Is this circuit similar to the ones in the Phony perpetual motion devices? thanks for another interesting video my friend 😀

It's Genius..

Sam from Look Mum No Computer had restarted and explained a few Master Clocks with pretty simple circuit

multivibrator, i think the additional cap is taking place of the flipflop

This video came out right on time, if you catch my drift ;)

Hi, is there anyway one could modify this circuit to be used in some sort of solenoid motor or a reed switch motor controller type thing? maybe with a joule thief circuit as well involved? take care and have a great day!

the sewing machin trick to build coils is awesome! (But aren't you supposed to count the loops?)

Could you pair this with a joule thief for extended run time?

The Pendulum is mightier than the Swordulum.

Classic blocking oscillator.

Any chance to see the ringing effect of such circuit's coil(s)?

I’m wondering if it could be adapted to use that coil & circuit as a form of guitar pick-up ?

How does the 47uF capacitor discharge? It only let's the pulses though, as a high pass, but were is the resistor to drain it?

Wow missed this one from 5 months ago .Now how can you use this as a perpetual motion machine

Doesn't the electrolytic discharge through both coils to give an extra kick?

What was that?! Is there someone under the table, squeezing your transistors? 😉🤣😂😍🥰❤

you shod make a video on making a clock with this

Hi Clive, maybe a dumb qestion, but anyway..... would it be useful in something called Swinging Sticks Sculpture? I am under some temptation to try to build it, so it would behelpful... Thanks, Stef

Not a great deal going on, they really have cut back as far as they can with the components. 2x👍

interesting

found my grandfathers clock. made it... 1930 maybe? its so weird, an axial ratchet escape gear, a worm gear reduction... and a solenoid driven pendulum. some terrible switch on the pendulum, appears to switch it so it retards the upswing as much as assist the down... and 50% duty... lol. meh. planning on giving it a little overcentering toggle, operate a set of switching reeds so it turns on just as its getting to the solenoids, toggles over ready for the return swing as it simultaneously turns off, then repeats... and dump the back spike into some neons around the face. pretty :) maybe distributed for hours/mins. no solid state allowed! well, i wanna stay period correct. except for threads. its getting metrics where needed.

I might actually attempt this one. How important are the specs, especially of the coils? Also is it would similarly to the one in Jewel Thieves?

Would be nice to see it working using an oscilloskop!?

A Bulle clock from the thirty’s has a much simpler circuit purely mechanically.

A very simple circuit that works well.

would love to see a step by step video on how to make a simple pendulum circuit - HINT HINT ;)

That capacitor is like a semi-diode...

How would the circuit need to be adapted for a string? Like for a powered Foucault pendulum.

Can you teardown LED backlight tester. Thanks

Would be nice to see the behaviour of this on an oscilloscope

What does the other coil on the other end of the board do?

Could you use this to turn a 7 day wind up clock into a continuous one?

Does the magnetic pulse repel or attract the magnet on the pendulum?

Hey Clive, what’s the right hand coil for with what appears to be a 32,768Hz crystal underneath it? Can this thing alter the timing of a swinging pendulum… oh no, I’ve just figured it out. It’s completely separate. There’s a quartz circuit for time keeping and the pendulum is just for show. Oh hell no, how hideous 🤦‍♂️

The Tennis Racket of Zeus (with design flaw). The mosquito zapping tennis racket sold at the Dollar or Pound Store would be a great item for you to disect. It is just up your alley. We bought one yesterday and it does zap the huge Canadian mosquitoes, dead! This looks like a tennis racket but has 3 layers of aluminum mesh sandwiched with 2 layers of plastic grid, and runs on 2 AA batteries. When you wave it at a mosquito and it enters the mesh ZAP!!! the mosquito is dead. The design flaw is as follows. When you push the red button, the red LED does go on as per the instructions. But when you release the button, the LED immediately goes out, leading one to believe that the racket is now safe. But it is definitely NOT safe. Pressing on the aluminum mesh with any force releases a whitish-blue spark straight into your finger. Youch!!! It does not really hurt and is kind of fun once you are used to it and expecting it. It is basically like rubbing your feet on the carpet and touching the doorknob, but on steroids. This could be a fun item for a Big Clive analysis and diagram. Cheers.

It seems there is a bit of confusion here, with the difference between the schematic and the PCB. The PCB came from a clock and I assume the 'crotch' between the legs of the PCB was where the AA cell holder was originally. Right? The 2SC1815 comes in four current gain ranges: O, Y, GR, and BL. Please tell us which gain range it is. Thanks, Clive.

Hi Clive, a quick question maybe you could help me with. In regard to DC circuits, is there a difference between using a solid conductor or using a multi stranded conductor ? This is in regard to model railway using up-to say 25v DC at about 6 Amps for points, Lights etc. Also DCC train controllers that output 16 Volt up-to 8 Amps. Pulse Width Modulation. Not quite DC nor AC but more like On/Off pulses of DC. Any help in this regard would be appreciated. Thanks for your time. Alan

The big mystery is how this is stable enough for a clock, since slightly more current causes a longer swing, slightly less current causes a shorter swing. The amount of current depends on the precision of a lot of analog components, battery voltage.

A bit big for wearing on the wrist. more SUITed for a Tie Pendulum ... I'd toss the battery, go with larger magnet n' coil, longer pendulum, solar cell, super capacitor. Wind once a decade. , ;)

Clive, could circuit be used to made a earth rotation clock? Those ones that have tiny blocks in a circle that as the earth rotates one by one the pendulum finger knocks down?

Can you make a Joule Thief out of that?

How does the clock circuit interface with the pendulum circuit?

Isn't this also the basic premise behind a Joule Thief?

I wonder if there's a way you could deliberately misconstruct the circuit so that the feedback between the mechanical and electronic parts would give chaotic oscillations?

Just trying to understand here, but you explained that the pulse of the feedback goes through the 47uF and into the base of the transistor. Is this because the capacitor is blocking DC current (after it initially charges) but passing an AC component of the pulse? That part of the video wasn't clear to me.

_"Super Potato Vision"_