Digital clock 50 60 cycle issue

[hameeds01]

I have a digital Clock which requires 110v, 60Hz but in my country we have 220v, 50Hz. Now for this purpose I am using stepdown transformer & I am feeding 110v, 50 Hz to my clock, now the problem with my Digital clock is that it runs slow, u can say - 35 sec per 24 hours

 

[betwixt]

Most digital clocks use the mains cycles as the reference clock. They divide by either 50 or 60 to provide the seconds count. It sounds like you are dividing by 60 when you should be dividing by 50 so you lose about 10 seconds every minute.

Manufacturers of digital clock ICs usually make them compatible with both frequencies so you may find a pin tied high or low that you can reverse to change the count ratio. Otherwise, you need to find the pin that monitors the mains frequency and provide a 60Hz signal of your own to replace the one from the mains.

Brian.

 

[ark5230]

Loss of 35 seconds in 24 hours should be attributed to something else. Had it been due to frequency of AC mains, the time lost should be of the order of 4 hours a day.

 

[FvM]

Most digital clocks use the mains cycles as the reference clock.

Do they? I can't find any at my home. I think, it has been the usual technique 30 or 40 years ago.

 

[hameeds01]

Do they? I can't find any at my home. I think, it has been the usual technique 30 or 40 years ago

then y the 50 60 cycle issue ??

 

[threephase]

The clocks that used mains frequency for timekeeping were referred to as "synchronous". They are rather old-fashioned and had a small synchronous motor inside, hence the direct correlation with supply frequency.

If by "digital clock" we are referring to a clock with digital display, it may derive its timekeeping from a 32.768kHz crystal (that's a round number in binary, allowing divison down to one pulse per second).

The original poster didn't say whether the clock had previously kept good time when powered from 110V/60Hz. If it did the mystery remains, otherwise it can be down to the accuracy of the crystal (they all have a tolerance, some are better than others).

3phase

 

[hameeds01]

The original poster didn't say whether the clock had previously kept good time when powered from 110V/60Hz. If it did the mystery remains, otherwise it can be down to the accuracy of the crystal (they all have a tolerance, some are better than others).

my sis was using the same clock in USA according to her it runs perfect no Time issue it had

 

[Jack// ani]

@hameeds01, any chance its a Philips radio clock you're talking about?

 

[karesz]

Hi @hameeds01,
Do it open pls and check the IC, then _as wrote betwixt too_ courch for the 50/60 Hz changing pin...
Its relativ inpossible with automatically changes & that your sis hasnt "time problems" with them in the states...
K.

Added after 2 minutes:

Of course, it is to check for another possibility too:
you have maybe more "outfalls"/breaks in your country as your sis in usa...

Added after 2 minutes:

For that check you can apply a(n bigger) battery for eventuell needed "time bridges"..
The most type of thes clocks has inside a small box/contener for that