On Thu, Feb 25, 2016 at 1:08 PM, Neil Green <nc...@hotmail.co.uk> wrote:
> I’ve decided to build this: > > http://www.hackersbench.com/Projects/1Hz/ > > which has an easy to follow diagram. Parts have cost less than £5. I’m not > expecting great things from it by any means, but it’s something I can get > my head around and should improve my understanding (a little). > Good start! Once you have built it and observed how sensitive it is to temperature variations, you might want to take a look at this: https://www.adafruit.com/products/3013 This breakout is based on the DS3231 chip, which is a temperature compensated 32 KHz real time clock with a built in crystal and optional battery backup. It also has a 1 pps output. It is reasonably stable and accurate out of the box, but if you want to adjust it you can send it commands from a microprocessor that tweak its frequency up and down in increments of about 0.1 ppm (about 3 seconds per year). It does this by switching in and out tiny on-chip capacitors. -- --Jim Harman _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
