Hourly timer.

[K1WY- Bo;;]

I am looking for a TCXO chip or circuit to produce a pulse each hour every hour. I need this to be as accurate as possible but also single chip if possible
and 3-5 vdc operating voltage. Can anyone direct me to a RTC TCXO chip that can do this?

I will use this to sync, on the hour, old Western Union self winding clocks.

Thank you

Bill

 

[JimB]

Hello Bill, welcome to the forum.

There are one or two clock enthusiasts on the forum who may be able to make an exact suggestion, but I don't know of one off the top of my head.

My initial thought was that TCXO an a handfull of logic chips would be a way to go, but if you want to limit the component count, you could use the TCXO to give an exact 10Mhz in conjunction with a micro controller to do the division to 1 pulse/hour.
This of course would need some software programming knowledge, I don't know if you have any experience in that area, but it would give a low component count solution.

Jim GM3ZMA

 

[cowboybob]

Welcome Bill,

For starters:
**broken link removed**
This may not suit your accuracy specs, but might be OK for the clock you're calibrating.

Anyway, low component count and simple construction.

CBB K4NFF

 

[ronsimpson]

I don't know of a 1hr part. but:
DS1307 has a output that will do 1hz. (1 second) but you need to turn on the output.
I can't find it now but there is a 8 pin IC that takes a color crystal down to 60/50hz.
I think SiLabs has xtal osc down to 0.1hz.

I have used a CD4060 (in your case two) to divide down to a very low frequency.
Start off with a color crystal or a watch crystal.

 

[KMoffett]

Not likely to find an off the shelf solution. I would go with a hacked 1.5V battery clock module to get a 1-pulse-per-second or 1-pulse-per-2 seconds clock. Then feed that to an 8-pin PIC and have it divide the clock input to a 1-per-hour output pulse.

Ken

 

[KeepItSimpleStupid]

You might be able to go with a variation of this: **broken link removed**

Note it tends to sync 2x/day and it might not have an extra pin available so you can create a 1 pph.

 

[NorthGuy]

32.768kHz watch crystal coupled with a microcontroller will gove the best precision with minimum of parts.

You can also go a different route - catch radio or GPS signal - this will not drift at all.