$ The Hyper Pendulums

[Kiggsia]

I think it's very common for the quartz movements with the fake pendulums to swing the small pendulums like in my mini schoolhouse clock at about twice the normal speed. I sure wish they were better engineered to not do that, it gets on my nerves. I have a fantasy that if a resistor or a rheostat dropped the battery voltage that the pendulum would slow down, like when a dustbuster nicad battery would discharge, the fan speed would decrease along with the battery weakening. My fantasy fades away when I think that if that would happen in a pendulum movement, they would have been designed to operate on a lower voltage?

 

[Kiggsia]

I think it's very common for the quartz movements with the fake pendulums to swing the small pendulums like in my mini schoolhouse clock at about twice the normal speed. I sure wish they were better engineered to not do that, it gets on my nerves. I have a fantasy that if a resistor or a rheostat dropped the battery voltage that the pendulum would slow down, like when a dustbuster nicad battery would discharge, the fan speed would decrease along with the battery weakening. My fantasy fades away when I think that if that would happen in a pendulum movement, they would have been designed to operate on a lower voltage?

I once was able to correct a lighting issue with a rheostat. I had hooked up green LED underdash floor lights in my car, & after a while they began to flicker. I had thought it was a design flaw, bugs in the LED type lights. But since car alternators put out 14 volts, it may be that these lamps I bought online may be intended for 12 volt solar lighting, like some incandescent 12 volt lamps are marketed for. So, not knowing what resistance value would drop 14 volts down to 12, I rooted around in a tray of electronic odds & ends trying different resistors. Finally, a rheostat worked to lower the voltage although it was very sensitive to movement of the shaft. After I tried the rheostat in the car for the underdash floor lamps, a very slightly noticable drop in light level but no more flickering. But with this clock, which I replaced a non chiming keywound movement with a quartz westminster and fake pendulum movement for a cousin's clock, i'm hoping she will say " Oh, i like that, it really lets me know the clock isn't running down like when it was a windup clock". But she will eventually realize that the pendulum uses it's own battery separate from the clock itself....

 

[bruce linde]

there are previous threads on how to minimize the pendulum swing of the quartz movements… Including one from me where I managed to successfully file away some of the magnet in the crutch… Less power, less swing, no need to mess with the movement

 

[Kiggsia]

there are previous threads on how to minimize the pendulum swing of the quartz movements… Including one from me where I managed to successfully file away some of the magnet in the crutch… Less power, less swing, no need to mess with the movement

Thanks for your reply. To put the quartz outfit in this mini schoolhouse clock I posted a video of, I had to cobble up a linkage, as seen in these two attachments of the pendulum mechanism. Im wondering if all the ferrous metal I added causes a greater magnetic attraction of the permanent magnet to the magnetic electric coil, & if I should try to use brass or aluminum instead of what I used?

 

[bruce linde]

Thanks for your reply. To put the quartz outfit in this mini schoolhouse clock I posted a video of, I had to cobble up a linkage, as seen in these two attachments of the pendulum mechanism. Im wondering if all the ferrous metal I added causes a greater magnetic attraction of the permanent magnet to the magnetic electric coil, & if I should try to use brass or aluminum instead of what I used?

i'm no expert... but i would think you added weight and not additional magnetic attraction.

the magnet is in the black plastic where the red arrow points. it's not that powerful, but grinding off maybe a third or a quarter of it made it less powerful.

since your quartz movement doesn't really care if there's a real pendulum (i.e., where the distance between the suspension spring flex point and center of mass of the bob/ball actually matter), you might also experiment with seeing how little weight you could get away with... .that might give less impetus to the amplitude of the swing.

might just be easier to try smaller magnets in the bottom of the crutch and find that point where you don't have enough magnet to keep it swinging at all, and then dial back....

 

[Kiggsia]

Thanks for your reply. To put the quartz outfit in this mini schoolhouse clock I posted a video of, I had to cobble up a linkage, as seen in these two attachments of the pendulum mechanism. Im wondering if all the ferrous metal I added causes a greater magnetic attraction of the permanent magnet to the magnetic electric coil, & if I should try to use brass or aluminum instead of what I used?

View attachment 754264 View attachment 754265

Tonight I took the magnet out of my pendulum crutch & began grinding it down, that metal almost cant be ground
at all. But about a third of the magnet broke off, so I tried using just the 2/3 piece and it didnt slow the pendulum speed down noticably, it only lessened its arc of travel. Then i tried the small piece & still no drop in speed, just in travel distance left & right.I removed my cobbled up linkage & put on one of those cheap false pendulums that come with the quartz movement kits. No difference in swing speed. But thanks for your info.
I

 

[praezis]

Physics will stay physics
Frequency of a pendulum depends on its length only. No matter what attrction, weight or magnet size you are changing.

Frank

 

[bruce linde]

sorry… I missed the part in your first post where you were saying you wanted to slow down the swing and read it as you wanted less amplitude.

what if you experimented with a second magnet below the pendulum assembly that exered a bit of a pull on the pendulum as it swung by?

 

[Kiggsia]

sorry… I missed the part in your first post where you were saying you wanted to slow down the swing and read it as you wanted less amplitude.

what if you experimented with a second magnet below the pendulum assembly that exered a bit of a pull on the pendulum as it swung by?

That would be worth a try for sure. Im thinking that the permanent magnet in the crutch & the electromagnet in the pendulum mechanism housing repel each other so im hoping that a magnet below the bob would attract the bob as it swings by & resist and slow down the pendulum. Yet it seems im the only person in the clock world that is seriously annoyed by the hyper speed of electrical pendulums......

 

[bruce linde]

you keep talking about 'hyper speed', and yet i have multiple quartz movements driving longer pendulums and the speeds seem completely appropriate.... shortest pendulums are in a banjo clock and a wall regulator, longest one is in a howard figure 8 knock-off... short pendulums swing faster, longer pendulums swing slower, as frank pointed out

 

[Kiggsia]

you keep talking about 'hyper speed', and yet i have multiple quartz movements driving longer pendulums and the speeds seem completely appropriate.... shortest pendulums are in a banjo clock and a wall regulator, longest one is in a howard figure 8 knock-off... short pendulums swing faster, longer pendulums swing slower, as frank pointed out

As can be seen in this low res videoclip,my clock has a very short pendulum. But my Daughter has a Bulova Cranbrook wall clock with a pendulum several times longer, but still that same excessive speed

 

[bruce linde]

quartz movements are cheap enough at timesavers... why don't you just pick up a few and do some testing to see if there are any differences across brands? or even call them and ask? they might have had this come up before.

 

[TQ60]

Already mentioned...it is a pendulum...

Shift gears to wind up clock.

Add weight and or distance to the Bob and it will slow down.

Not sure how often the clock pulses the drive, but the pendulum is just like a bell, it has it's own frequency.

Fill the Bob with sand

 

[Tim Orr]

Good afternoon, all!

Some concerns here: I am not sure that the pendulum in question is functioning exactly as a pendulum would in an ordinary clock. I have seen, and I think most of us have, cheap electric clocks with pendulums that flit back and forth with astonishing speed. I do not believe this is because they are "short." Some seem also to be moving back and forth with no typical deceleration at the high point of the swing on both sides.

They appear to me to be "driven" rather than "swinging." There appears to be little of anything "free" about them. If they were behaving according to strict pendulum "rules," then Bruce's adjustments would, I think, not have worked.

Best regards!

Tim Orr