1 Hertz Clock Timer

[frosty]

on the ic where the outputs for a relay?

 

[kchriste]

You need to drive a transistor with the IC. Then the transistor drives the relay. Generic instructions here:
**broken link removed**
(from )

 

[Boncuk]

It's easy. It is one pulse every 2 minutes or 120 seconds
32.768 kHz
Divide by 2^15 (32,768)
Divide by 60
Divide by 2

That can be done with standard ICs, but it is less wiring with a PIC

Thank you Diver300,

after some mental calculation I've gotten a similar result: divide by 2Λ15, divide by 10 and divide by 12.

It's already posted.

Hans

 

[Diver300]

It's been a long time since I've used that chip. It really depends on the crystal type and cut. Overtone SC cut crystals can't be tuned very far off. AT cut crystals can be pulled further off than SC cut crystals.

SC cut crystals are only for use in oven oscillators, and they are very difficult to use.

With AT cut crystals, the amount that they can be pulled is inversely proportional to the square of the overtone. That means that 3rd Overtone crystals have 9 times less pulling than a fundamental crystal for the same change in load.

As overtone oscillators have to be tuned to stop oscillation at other modes, it is more difficult to change the load on them.

As a result, the pulling range of overtone oscillators is extremely limited.

 

[frosty]

I have that part done, I will be using the Ic4521 using the crystal and a relay.

 

[frosty]

15m timer

Here is what was down load by on1aag. But theres no pin hookup for a relap,and not knowing how get the 15m on and off. View attachment 4521.pdf

 

[kchriste]

You won't be able to it with only that chip while using that crystal frequency. You either need to use a lower frequency crystal or cascade another divider IC after the 4521.

 

[frosty]

Hi, If I use a 4194304 hz cryztal,but what pins should I use for the relay hookup.????

 

[kchriste]

The max divide ratio is 2^24 which means that your minimum frequency with a 4194304hz crystal is 0.25hz which would give you 2 seconds on and 2 seconds off. You'd need a second IC.

 

[frosty]

I plan on using a 32,768 crystal, with a 5555 ic.

 

[kchriste]

5555???? Do you mean 555? You can't use a 555 with a crystal. At least I've never seen it done.
A 32768hz crystal would require a divide by 58,982,400 for 15min off and 15min on. The max divide on the 4521 is 16,777,216.

 

[frosty]

Hi, yes they make a 5555, or 7555, chip, also the crystal, How do you get those numbers on the, I don't understand how to fig. the times????

 

[blueroomelectronics]

The 5555 / 7555 or any 555 will not work directly with a crystal.

 

[frosty]

What will?????

 

[ericgibbs]

What will?????

hi,
Look at this timer ic.
Drive it with a CMOS 4049 and a 32.768KHz xtal and a predivider.

 

[frosty]

Thank You eric, I'm not that good in electronic, but I try, How would i hookup the4049? also I need a relay to be triged.???

 

[KMoffett]

Ormo...are you still around?

I used the following circuit to generate a 1Hz clock form the 60HZ power line. I added a second ÷60 section (2 more 4017s) to get a 60sec output. Hope this helps.

Ken

 

[ericgibbs]

Thank You eric, I'm not that good in electronic, but I try, How would i hookup the4049? also I need a relay to be triged.???

hi,
Look at this pdf, shows a number of simple osc options.
Ask if have problems.

If you speak nicely to member, BigAl Scorpio I believe he has some of these UA2240 ic's.

 

[kchriste]

How do you get those numbers on the, I don't understand how to fig. the times????

You calculate the period of a signal by taking the inverse of the frequency. So a 100hz waveform takes 1/100 of a second to repeat itself. A 60hz waveform takes 1/60 of a second to repeat itself, etc. You need a 30 minute period (15 on & 15 off) which is 30 x 60 = 1800 seconds long. The period of 32768hz is 30.5176 microseconds long, so 1800/0.0000305176 = 58982400 which is the divide ratio you'd need.

 

[frosty]

thank you kchriste, now I understand, how do I use this fig. 5898240 is it for the time.????