Cheap Chinese Clocks, Adj ?

Many have pcb trim links.

I have a unique one fitting that description, losing time badly. After swapping the 32kHz crystal, it's dead-on.

Cheers, James Arthur

"amdx"

** That is a fault.

The mechanism is worn out or he AA cell is weak.

Needs to be a good alkaline with at least 1.35V at the terminals.

... Phil

New Battery. Good Battery.

Yes, push it forward 4 minutes each morning.

What manner of cheap Chinese clock? Crystal controlled mechanical clock? Real time clock? Accutron clone? LED clock? CPU clock? Maker and model? Any hieroglyphics on the package?

Do the math. 4 minutes out of 1440 minutes per day is an error of

0.28% or 2800 ppm. You're not going to be able pull a 32.768 Khz xtal that much. If you're lucky, can pull maybe 50 ppm. Translation: It's probably busted.

However, if the above doesn't apply, it would really nice if you would take the time to disclose what the [deleted expletive] you're working with.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Oops. I forgot that it's not symmetrical. The basic accuracy is +/-

20 ppm. The adjustment range is typically about -120 ppm to +60 ppm. That's still much less than 2800 ppm.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

** But not an Energizer or a Duracell - right ?

Does the second hand progress smoothly round the dial ?

9 is the worst position.

... Phil

It is an Energizer at 1.612V. Hits every second even around the 9.

Certainly not on the cheap chinese clocks I've bought. Making them adjustable would cost more.

If it's newish, take it back for replacement or refund.

If it's not new, but has only recently started losing, with a good battery, it's probably about to die.

Sylvia.

Do you have a link to this poor quality clock ??

The most recent ones don't any more but older ones did have a trimmer capacitor you could tweak. However, losing 4 mins a day is so far off that the device is probably mechanically failing (stalling at 10 to 2?). I doubt if you could pull one of the little 32kHz tuning fork xtals that far off its resonance. You can easily buy a replacement.

I had to jump through a lot of hoops to make a battery powered sidereal clock that would gain 3m 56s per day once upon a time. Badly trimmed RTC chips tend to be +/- 15s per day like Meade SCT telescopes.

--
Regards, 
Martin Brown

Mine is advancing 4-5 min every hour, and it's portable radio clock,

First, I think it's impossible for my power line running faster than 60 Hz that much...

I manage to open it and break the plastic cover, frustrating I put it back and find another at the store cost about $8

A pity it's not gaining 4 minutes each day, sidereal time.

--
For a good time: install ntp

If you can't adjust it, try giving it a good smack on the table ?

Then sell it on ebay as "unable to test". Call it an "anti-sidereal" clock.

For a cute circuit borrowing the 60 cycle stuff floating in the air and achieving atomic standatds, see techlib.com Generally, you are supposed to throw it away and buy another. :) Crowd-sourced QC. jb

Faulty crystal, is my bet. Had one in a run of 25 units of a device I designed. All were assembled the same way, using a "reputable" source for the crystals.

I'll give that job to the wife. Mikek

That would be unethical. Hey, my wife bought that at a yard sale, so she got it in an unethical sale, does that make it ok to sell the same way? Just kidding, Mikek