Digital Clock Speeding Up (ie Gaining Time)

Most mains powered clocks derive their time form the 50Hz mains which is very accurate over a long time period. So your clocks are most likely picking up noise on the mains that is causing missing pulses or some such problem. Try adding a good mains filter to the clock, or just get a clock that does not rely on the 50Hz mains (usually the battery powered type).

Dave :)

"David L. Jones" wrote

Most mains powered clocks derive their time form the 50Hz mains which is very accurate over a long time period. So your clocks are most likely picking up noise on the mains that is causing missing pulses or some such problem.

Brian Goldsmith

Oops, I meant "extra" pulses.

Dave :)

During the unpowered periods, the internal ( battery powered) time base oscillator takes over - and it runs a tad fast.

Maybe the missus uses it power outlet for her vacuum cleaner or her steam iron or her ............

....... Phil

On 17 Oct 2006 01:12:55 -0700, snipped-for-privacy@mail.tpg.com.au put finger to keyboard and composed:

There was a clock that featured in a thread at sci.electronics.repair some years ago that was affected by off-peak pulses or "remote-reading electrical power meters" or similar signals.

- Franc Zabkar

Thanx 2 everyone who replied.

When you say battery powered clocks, do you mean regular alkaline batteries? If so, wouldn't battery powered clocks lose time when the battery goes flat? And, wouldn't they go flat often?

I don't think my clock has a battery at all. Whenever power is lost the clock is reset to 12:00.

I noticed the clock on my microwave keeps the right time. Does that sound right if there is a problem with the power here?

Is this the type of filter I should be looking at getting?

You asinine Google Groups WANKER !!

...... . Phil

No, an LCD display clock should last for years, just like a digtial watch. Something like this:

That means it most likely has better designed circuitry (filtering) that gets pulses from the 50Hz mains. With your other clocks you have just been unlucky with a poorly designed product - twice.

None of them seem to have the word "filter" in them, just "surge protection", that is different. Not that a filter is guaranteed to work anyway, cheaper to simply buy an LCD digital clock.

Dave :)

I mentioned it Phil, in my first post. Dave :)

Thanx 4 your help Dave.

I'll get myself an LCD clock.

David L. J> > Thanx 2 everyone who replied.