thats ok, so two 4060? you're referring to the built-in oscillator 32k or external crytsal?

Hi,
Not two 4060, but one 4060 with external gate logic, also there is no built-in 32kHz

 

Hi,
Not two 4060, but one 4060 with external gate logic, also there is no built-in 32kHz

Ahh, ok if I need to order parts not a big deal. If I have to order parts, maybe have it be selectable 10 mins or 15 mins if possible

 

The powerline AC is quite accurate when averaged on the long run.
Let's say you are NOT located in North America, with a powerline frequency of 50 Hz, then the total divider ratio would be:
15 X 60 X 50 = 45000.
A pair of counters and some gates to decode it.

 

hi.
This is the HEF4060 PDF, ref fig #5.
E

 

if you are generating clock using some RC oscillator (like NE555), you can set the frequency low... such as 1Hz. then you only need one counter to get longer intervals.

if you want precision, then RC based clock is not going to cut it. you have to use crystal. but lowest frequency crystal is 32kHz. in this case you need two CD4060. one to get crystal frequency down to a low base (like 1-2Hz) and then additional CD4060 to count those seconds to get 15min interval. so in this case you would need two of them.

or... get something programmable... like DigiSpark or Arduino and write something like... i don't know...

bool out_state;

void setup() {
  pinMode(0, INPUT);             // PB0 is an input for switch to select pulse polarity
  pinmode(0, INPUT_PULLUP);
  pinMode(1, OUTPUT);            // PB1 is an output
}

void loop() {
  out_state=digitalRead(0);      // read state of the input (LOW/HIGH)
  digitalWrite(1, out_state);    // write it to an output
  delay(1000);                   // wait 1 sec (1000ms)   
  digitalWrite(1, !out_state);   // toggle output
  delay(900000);                 // wait 900 second (900000ms)
}

 

Does it have to be one pulse every 15 minutes, or is every 16 minutes acceptable?

An alternate approach is a programmable lamp timer plus a 5 V wall wart. Every 15 minutes, the wall wart is powered up, makes the output pulse, and then just sits there. It is turned off after 1 minute, then turned on again in 14 minutes. Repeat. The output pulse circuit is 2 transistors, or 2 logic gates, etc.

ak

 

Does it have to be one pulse every 15 minutes, or is every 16 minutes acceptable?

An alternate approach is a programmable lamp timer plus a 5 V wall wart. Every 15 minutes, the wall wart is powered up, makes the output pulse, and then just sits there. It is turned off after 1 minute, then turned on again in 14 minutes. Repeat. The output pulse circuit is 2 transistors, or 2 logic gates, etc.

ak

yes the pulse needs to be every 15 mins

 

Or I could have it be triggered from external logic high to START the 15 mins timer, maybe that would be better?

also to once the timer starts i just need one pulse it don't have to be "on" the whole 15 mins

 

why don't you come up with some specs?what is this used for? what is the 1sec pulse actually doing every 15min?

 

It will be playing a digital message every 15 mins that is from other device. The timer circuit would trigger that.

 

29 posts and you're tying yourself in knots trying to come up with a plan.

 

Why don't You just tell everyone what the purpose of this project is ?
You would very likely get some excellent recommendations immediately, instead of all this guesswork.
.
.
.

 

29 posts and you're tying yourself in knots trying to come up with a plan.

it could be worst..lol

 

Why don't You just tell everyone what the purpose of this project is ?
You would very likely get some excellent recommendations immediately, instead of all this guesswork.
.
.
.

I did a couple post up

 

it could be worst..lol

Stubbornness does come with certain costs.

 

Stubbornness does come with certain costs.

lol true

 

Hi,
The accuracy is not dependent upon the 4060, but the driving oscillator.
E

The 4060 has a built-in oscillator, and it's not very accurate. Only as good as any CMOS gate oscillator, which isn't too good.

 

The 4060 has a built-in oscillator, and it's not very accurate. Only as good as any CMOS gate oscillator, which isn't too good.

ahh ok is that in general or when running it for long periods of time? Would it be better to have it only start the 15-min timer when triggered?

 

ahh ok is that in general or when running it for long periods of time? Would it be better to have it only start the 15-min timer when triggered?

It would be repeatable.
You can make a monostable out of a 4060 by feeding the output back to the oscillator with a diode, but the accuracy will be the same.

 

It would be repeatable.
You can make a monostable out of a 4060 by feeding the output back to the oscillator with a diode, but the accuracy will be the same.

What would you guess the accuracy would be by doing it that way?