Digital Clock

[Mr S.S.Datta]

Pl let me how to connect the crystal controlled ckt to the digital clock radio Sonashi. IC in unit is SC8560. I have tried using National Sem IC MM5369 with 3.579 MHZ crystal but the display flickers.
Thanks
Datta

 

[Krumlink]

You cant have your pudding until you eat your meat!

 

[mvs sarma]

Pl let me how to connect the crystal controlled ckt to the digital clock radio Sonashi. IC in unit is SC8560. I have tried using National Sem IC MM5369 with 3.579 MHZ crystal but the display flickers.
Thanks
Datta

elaborate what you want? do you want that the clock radio should work only with battery and be able to show time? it can be done by driving the displays with the same clock as what is driving the count. this was published in the forum earlier for a similar clock with the same chip.

try to study the link below.

https://www.electro-tech-online.com...adio-50hz-drifts.25784/?highlight=radio+clock

 

[Mr S.S.Datta]

Thanks for reply
I am also facing the same problems as mentioned by Arun & Manoj
I have gone through the postings and found that Arun & Manoj were successful but they have used batteries and some other divider ckt.
I want the clock to work on mains and battery 9v only for backup.

 

[mvs sarma]

you have to set the clock as 50Hz by manipulating the %)/60Hz signal
But, bear it in mind that, the public mains in countries like India is never 50Hz. it is near 48 or at times 47.xx with somuch of national GRID. Thus your clock will never show correct time.So the need for crystal time base.

Once crytal time base iss used for accuracy, the display can't perhas be driven.
this is like a "seed or tree -first" situation. i hope you appreciate that both problems land in the same solution. OK, anf size purpose, you may use SMD components and tuccck the add on to the main clock. Yes. it can run from mains and display can be blanked during failure, but when mains restore the display will be driven by the crystal derived signals only and not from mains as the lamps start blinking and will be blurr.

 

[k7elp60]

Pl let me how to connect the crystal controlled ckt to the digital clock radio Sonashi. IC in unit is SC8560. I have tried using National Sem IC MM5369 with 3.579 MHZ crystal but the display flickers.
Thanks
Datta

The MM5369 IC although old has an output of 60 HZ with a 3.579 crystal and it draws very little current from the Vdd. It will work on 3-18V.
Still not sure of your problem.

 

[mvs sarma]

A set of mm5369aa/n and 3.579545 are dam costly, at least in India. so people go for other methods of deriving 60 /50 Hz.

 

[Mr S.S.Datta]

The MM5369 IC although old has an output of 60 HZ with a 3.579 crystal and it draws very little current from the Vdd. It will work on 3-18V.
Still not sure of your problem.

Hi
Thanks for reading my message.
The main IC is LM 8560 & display is a module having 2 inputs cycle 1 & cycle 2 from the mains transformer ( Pl see if possible diag as shown by mfg.). It also gets 50/60 hz input from mains transformer.
I tried removing the mains 50/60 hz input and giving input to pin 25 of the IC from the MM 5369 - 3.579..crystal , the display flickers at a very fast rate.( In this case the supply ie pin 8 is Vss and when pin 8 is Gnd then display shows I P : 6 8
I have made a simple clock using this cry & ic comb with display using discrete LED, IC module of National Sem make, but that was made about 25 yrs earlier and it is still working fine.
Datta

 

[Mr S.S.Datta]

A set of mm5369aa/n and 3.579545 are dam costly, at least in India. so people go for other methods of deriving 60 /50 Hz.

Hello Sarma
I have this with me purchased many yrs ago since it was there in my stock thought of trying to use it.
The main IC is LM 8560 & display is a module having 2 inputs cycle 1 & cycle 2 from the mains transformer ( Pl see if possible diag as shown by mfg.). It also gets 50/60 hz input from mains transformer.
I tried removing the mains 50/60 hz input and giving input to pin 25 of the IC from the MM 5369 - 3.579..crystal , the display flickers at a very fast rate.( In this case the supply ie pin 8 is Vss and when pin 8 is Gnd then display shows I P : 6 8
I have made a simple clock using this cry & ic comb with display using discrete LED, IC module of National Sem make, but that was made about 25 yrs earlier and it is still working fine.
Datta

 

[Mr S.S.Datta]

you have to set the clock as 50Hz by manipulating the %)/60Hz signal
But, bear it in mind that, the public mains in countries like India is never 50Hz. it is near 48 or at times 47.xx with somuch of national GRID. Thus your clock will never show correct time.So the need for crystal time base.

Once crytal time base iss used for accuracy, the display can't perhas be driven.
this is like a "seed or tree -first" situation. i hope you appreciate that both problems land in the same solution. OK, anf size purpose, you may use SMD components and tuccck the add on to the main clock. Yes. it can run from mains and display can be blanked during failure, but when mains restore the display will be driven by the crystal derived signals only and not from mains as the lamps start blinking and will be blurr.

Dear Sarma
Perhaps u may not be aware that many yrs ago National Sem Conductors had introduced IC module which could be run using the above cry/ic comb. In this case discrete LED were used to display time and transistors were used to drive the LED . I have made one such unit at that time and still the clock is working fine giving accurate time.
Datta

 

[mvs sarma]

Fine SS Datta, if you don't have issues with the set


all the best

 

[Mr S.S.Datta]

Dear Sarma
Thanks
Perhaps u have not followed what I meant to convey. In the Sonashi clock radio which I am having now, the LED display is a block module it has 2 inputs cycle 1 & 2 which gets power from 230 v mains it is this which drives the display and the 50/60 hz input is separate given to pin25 of LM 8560 is also from the mains. (If possible see IC diag) In view of stability of our mains freq. this does not give accurate time. So I tried using a cry/ic as clock input to LM 8560 instead of the mains 50 hz, but it does not work. Do u have any suggestion.
Regards
Datta

 

[mvs sarma]

Datta jee,
I was not telling about MM5369aa/n and 3.579545MHz.
i was not even talking abt adopting the 60Hz dervied from the above chipset to the clock chip under concern.

I along with many others who worked for this problem(what post you saw) for some time. we also know the display and the cycle 1&2 .

Now, i want to clarify, that once you go for crystal time base, the display also should have cycle 1&2 derived from the is very time base and not from Mains. If not it will end up in flicker only.
what i was emphasizing is, regardng cost and availability
of mm5369
so the team has built a cheaper alternative to 50Hz base, including cycle1&2 to sync with the clock driving the clock., and we succeeded.

 

[Mr S.S.Datta]

Dear Sarma
Sorry if I have hurt u, since I have the cry/osc I would like to know in that case how it could be done, do u have any circuit which can be tried.
Thanks
Datta

 

[mvs sarma]

Dear Sarma
Sorry if I have hurt u, since I have the cry/osc I would like to know in that case how it could be done, do u have any circuit which can be tried.
Thanks
Datta

the element that was updatesd and brought out by Nura is attached here for your convenience. th clocke from 5369 can be inputted to this element and it works. Perhaps a sigle transistor buffeat the output of 5369 helps protect the chip. Hope to see result of your implementation, sir,

PS : Don't confuse. the definitions of Vdd and Vss are reversed for this national chip for reasons known to them.

 

[Mr S.S.Datta]

Dear Sarma
Thanks for sending the ckt. I shall let u know the results after I try it out.
Regards
Mr Datta

 

[mvs sarma]

I hope SS Datta might have a working clock after the suggested modd, by now.

 

[sateeshgoud1395]

digital electronic clock

sir please give me crystal 3.2768MHZ with 4541 ic and main ic 8560 digital electronic clock occurency function circuit i have one circuit but its function is after 24 hrs it working 3 seconds slow am replace the pf,s but no uses give the suggetion are circuit

regards
sateesh goud

 

[mneary]

3 seconds per 24 hours is 34 parts per million. What is the accuracy rating of your crystal?

 

[xbox2pal]

i need the design and consruction of the LED digital clock i asked about because i am in need of them