1Hz Clock Signal

[xXAxHillbillyXx]

I am in the process of building a binary clock and realized that i need a good 1Hz signal that i just cannot get from the 555 IC I found this schematic and was wondering if it would work and be worth building I dont want to program any chips and i tried pulling the clock PCB out of a wall clock but that didnt work. this schematic seems easy enough to follow and was wanting some input on it.
https://www.efymagonline.com/pdf/circuit-2.pdf
Thanks,
Nick

 

[Brevor]

It looks like it should work OK, I think the circuit for the crystal is a little more complicated than it needs to be but it shound be good.

 

[xXAxHillbillyXx]

Good deal as long as it will work i am gonna build it... THANKS!!

 

[RCinFLA]

You can get a CD4060BC CMOS IC that has an oscillator and 15 stage ripple counter to take 32.768 Khz xtal down to 1Hz.

Or you can take the 1 pps that comes out just about all GPS receivers if you want extreme accuracy.

 

[xXAxHillbillyXx]

I am just wanting it as accurate as a wall clock but i have having some trouble finding the jfet (bfw10) is there an equivalent jfet i can use? will any n-type jFet work?

 

[Diver300]

You can get a CD4060BC CMOS IC that has an oscillator and 15 stage ripple counter to take 32.768 Khz xtal down to 1Hz.

The CD4060 is only a 14 stage counter, so it will only get down to 2 Hz

 

[Diver300]

I am just wanting it as accurate as a wall clock but i have having some trouble finding the jfet (bfw10) is there an equivalent jfet i can use? will any n-type jFet work?

This circuit works very well and you don't need the inductor.

Pierce oscillator - Wikipedia, the free encyclopedia

 

[colin55]

Take the signal from a $5.00 wall clock. It is crystal controlled.
What circuit did you use?

 

[KMoffett]

What colin55 said.

This is how I did it: https://www.electro-tech-online.com/threads/60hz-pulse-generator.87453/#post683379

Ken

 

[xXAxHillbillyXx]

diver300-Ok I am really liking the looks of the Pierce oscillator but, what component values make it 1Hz or do i still need to build the divider part of the circuit? i havent acctually built anything yet but as far as accuracy goes we are not talking about military precision accuracy here just you average clock.

This one seems to be based off of the pierce oscillator and has the divider allready shown on the circuit is it what i acctually need to build? https://en.wikibooks.org/wiki/Practical_Electronics/Plugins/1Hz_Oscillator

 

[Boncuk]

Hi HillbillyxX,

a clock normally has nothing much to do much with military precision, which is waaaay off in many cases.

Here is a circuit providing an accurate 1Hz signal if the oscillator circuit is tuned precisely. The frequency of 32.768KHz is most commonly used in wrist watch circuits and is fairly accurate if the watch is worn day and night for least temperature changes - hence crystal frequency changes.

I'd be pretty much disappointed if my timepiece were off more than 1 second per month. It cost me 350€ and is a PULSAR (daughter of SEIKO) with a big advantage over all clocks I had purchased before: The battery takes care of accurate time keeping for a period of six years before replacing it.

The PCB just requires 1.55X1.7625inches.

To maintain precision the circuit should be kept at constant temperature (e.g. arm pits

If you want to build the circuit as shown please PM me for the Eagle files - free of course. What else?

Regards

Boncuk

 

[crutschow]

This one seems to be based off of the pierce oscillator and has the divider allready shown on the circuit is it what i acctually need to build? Practical Electronics/Plugins/1Hz Oscillator - Wikibooks, collection of open-content textbooks

That circuit should do what you want.

 

[Boncuk]

That circuit should do what you want.

Why do you suggest a circuit using one more IC than my suggested one?

There is not even a part allowing precise clock frequency adjustment.

 

[crutschow]

Why do you suggest a circuit using one more IC than my suggested one?

There is not even a part allowing precise clock frequency adjustment.

I didn't suggest the circuit. He asked if that circuit would work. I answered his question.

He also stated he didn't need it to be highly accurate.

 

[xXAxHillbillyXx]

Hi HillbillyxX,

a clock normally has nothing much to do much with military precision, which is waaaay off in many cases.

Here is a circuit providing an accurate 1Hz signal if the oscillator circuit is tuned precisely. The frequency of 32.768KHz is most commonly used in wrist watch circuits and is fairly accurate if the watch is worn day and night for least temperature changes - hence crystal frequency changes.

I'd be pretty much disappointed if my timepiece were off more than 1 second per month. It cost me 350€ and is a PULSAR (daughter of SEIKO) with a big advantage over all clocks I had purchased before: The battery takes care of accurate time keeping for a period of six years before replacing it.

The PCB just requires 1.55X1.7625inches.

To maintain precision the circuit should be kept at constant temperature (e.g. arm pits

If you want to build the circuit as shown please PM me for the Eagle files - free of course. What else?

Regards

Boncuk

Yes, Please PM me the eagle files! But will this trimmer cap work? and why do your resistors in the schematic and board say 4M7 and 2K2? is that a 4Mohm and a 2kohm or a 4,000,007 ohm and a 2002ohm? Cuz i read that as "two thousand two" and "four million seven". I may just be an idiot but i have not ever seen it like that before. sorry for all the questions.

 

[Boncuk]

Hi Hillbilly,

PMing any files is impossible. You will have to inform me about your email address for the files, which can be attached to a mail in any format.

4M7 means 4.7MΩ = 4,700,000 Ohm, 2K2 means 2.2KΩ = 2,200 Ohm.

It would be kind of nonsense to have a resistor with a value of 4,000,007 Ohm. Even a 1% tolerance 4M7 resistor might have a value of 4,747,000 Ohm or 47KΩ below the nominal value.

The trimmer cap has enough capacitance to compensate for crystal inaccuracies.

Regards

Boncuk

 

[Boncuk]

I didn't suggest the circuit. He asked if that circuit would work. I answered his question.

He also stated he didn't need it to be highly accurate.

Hi Carl,

beg your pardon if stepped on your feet. I really didn't mean it.

I'm just a time keeping freak and had as many a 28 clocks distributed all over my house in Germany. Most of them were nuclear clock synchronized (DCF77, Mainflingen/Frankfurt/Main) with a deviation of 1 sec within 30,000 years.

I guess I won't miss that second if I gain that age.

Regards

Hans

 

[xXAxHillbillyXx]

Hi Hillbilly,

PMing any files is impossible. You will have to inform me about your email address for the files, which can be attached to a mail in any format.

4M7 means 4.7MΩ = 4,700,000 Ohm, 2K2 means 2.2KΩ = 2,200 Ohm.

It would be kind of nonsense to have a resistor with a value of 4,000,007 Ohm. Even a 1% tolerance 4M7 resistor might have a value of 4,747,000 Ohm or 47KΩ below the nominal value.

The trimmer cap has enough capacitance to compensate for crystal inaccuracies.

Regards

Boncuk

Yeah I thought that the resistor values i was getting to were just not right lol I will PM you my email addy in just a few minutes. Thanks again!

 

[Mikebits]

FYI, I just came across this off the shelf 1Hz oscillator.
https://www.electro-tech-online.com/custompdfs/2010/07/DQXO3SM2028101442920REV20C.pdf

 

[Diver300]

You can get a CD4060BC CMOS IC that has an oscillator and 15 stage ripple counter to take 32.768 Khz xtal down to 1Hz.

Or you can take the 1 pps that comes out just about all GPS receivers if you want extreme accuracy.

Does anyone know how to enable the 1pps signal? I've received information from GPS receivers, and written code that parses the signal, but I don't know how to send data to the GPS receiver to do things like change the baud rate or turn on the 1 pps.