View previous topic :: View next topic |
Author |
Message |
nyrath Newbie
Joined: 31 Oct 2010 Posts: 2
|
Posted: Sun Oct 31, 2010 11:29 am Post subject: Quartz oscillator crystals source? |
|
|
I am trying to make an astronomical clock. I need a reasonably inexpensive method of turning a clock shaft 360 degrees in one sidereal day (about 23.93447 hours), and a way of turning the shaft 360 degrees in one Lunar tidal day (about 24.84111 hours).
I did stumble over a quick and dirty way to do it here, by hardware hacking common garden variety clocks:
http://adsabs.harvard.edu/full/1988JBAA...98...89M
http://adsabs.harvard.edu/full/1987JBAA...97..348M
Basically one takes a dirty cheap quartz kitchen clock movement, and swaps the quartz oscillator for one that will turn the hour hand at the desired rate. You use three separate movement, but that's OK, they are cheap.
What I want to know is if anybody knows a good source of oscillators?
In the design, the author uses a 24 hour movement for the mean solar day hand, and 12 hour movements for the sidereal and lunar hands.
I gather that the standard oscillator for a 12 hour movement is 0.032768 MHz (2^15 Hz) since it can be easily binary divided into one second.
If I have done my math correctly, this means that a sidereal 12 hour movement would need a 0.032858 MHz oscillator, and a lunar 12 hour movement would need a 0.031658 MHz oscillator.
(this will make a sidereal movement that does 360 degrees in 1/2 a sidereal day, but a 2:1 gear train can turn it into the desired 360 degrees in 1 sidereal day).
Anybody have a source? |
|
Back to top |
|
 |
|
 |
Alan Site Admin

Joined: 29 Jan 2006 Posts: 1399 Location: Winnipeg, MB
|
Posted: Thu Nov 11, 2010 2:25 am Post subject: |
|
|
I would have a look at Mouser or Digikey, they both have tons of parts available and good systems to search through them
http://mouser.com
http://digikey.com |
|
Back to top |
|
 |
nyrath Newbie
Joined: 31 Oct 2010 Posts: 2
|
Posted: Sun Nov 14, 2010 8:19 pm Post subject: |
|
|
Thanks! |
|
Back to top |
|
 |
|
|
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|