bobleny Posted November 25, 2006 Report Share Posted November 25, 2006 I'm building a clock and would like to produce a steady 1hrz signal. Obviously, the more accurate it is, the better!Now, I know it's almost impossible to get exactly 1 pulse per second, but I defiantly want it to be close.Any suggestions?Thanks! Quote Link to comment Share on other sites More sharing options...
MP Posted November 25, 2006 Report Share Posted November 25, 2006 The most accurate way to do this is to use a crystal oscillator and a divider circuit. It can also be done accurately with a micro, since you program the timing. This is basically the same as a programmable divider since all functions in the micro are based off the clock cycles of the micro.MP Quote Link to comment Share on other sites More sharing options...
bobleny Posted November 25, 2006 Author Report Share Posted November 25, 2006 Would a micro controller work good for this? Quote Link to comment Share on other sites More sharing options...
mvs sarma Posted November 25, 2006 Report Share Posted November 25, 2006 Hi,Lovely TOPIC. there are time signals broadcast terestrially. like 10MHz, 15MHZ and many other. they provide time ticks at 1sce-- these are controlled by atomic clock . second , you should have DCXO- which provides a good standard clock and derive 1sec from this clock-- appears foolish is it not-- but when you used dead perfect 1sec pulse-- you may appreciate perhaps Quote Link to comment Share on other sites More sharing options...
MNA Posted November 25, 2006 Report Share Posted November 25, 2006 The most accurate way to do this is to use a crystal oscillator and a divider circuit. It can also be done accurately with a micro, since you program the timing. This is basically the same as a programmable divider since all functions in the micro are based off the clock cycles of the micro.MPhttp://www.electronics-lab.com/projects/oscillators_timers/015/index.htmlI built a clock with 555 timer and dual decade counters......But it wasn't accurate obviously because of 555....As MP said crystal oscillator will be better.....the above project can be extended to make hrs/min/sec clock.....u will have to use gates to reset the hours section when it strikes 24....... Quote Link to comment Share on other sites More sharing options...
Fowkc Posted November 25, 2006 Report Share Posted November 25, 2006 If you're powering your device from the mains, another option is to divide down your 50/60Hz signal to get 1Hz.Not particularly accurate, as the mains frequency wavers quite a lot. If you assume a +/- 1Hz deviation, that could be 30 minutes off in a day!Of course, most of the time the deviation is a lot less than that. It's quite interesting to see what happens the the frequency based on demand:http://www.dynamicdemand.co.uk/grid.htm Quote Link to comment Share on other sites More sharing options...
bobleny Posted November 25, 2006 Author Report Share Posted November 25, 2006 Ok, crystal oscillators it is! Does any one know where I can look at some? Does anyone have any suggestions for what I should look at? Quote Link to comment Share on other sites More sharing options...
MNA Posted November 25, 2006 Report Share Posted November 25, 2006 Ok, crystal oscillators it is! Does any one know where I can look at some? Does anyone have any suggestions for what I should look at?u need a crystal of some frequency,then divide that frequency to suit your need......didn't u look at the project of the electronics-lab project section? ....... Quote Link to comment Share on other sites More sharing options...
mugsby Posted November 26, 2006 Report Share Posted November 26, 2006 see:http://en.wikipedia.org/wiki/Phase-locked_loop Quote Link to comment Share on other sites More sharing options...
mvadu Posted November 27, 2006 Report Share Posted November 27, 2006 The simple most circuit for this would be to take the circuit chip out of a dead watch or a table clock. They use a crystal oscillator and dividing technique. You need to cut off the coil winding and add two diodes (IN4148) on both the outputs (P side of it) and join the N-side to get study 1-Hz clock. Quote Link to comment Share on other sites More sharing options...
mvs sarma Posted November 27, 2006 Report Share Posted November 27, 2006 The simple most circuit for this would be to take the circuit chip out of a dead watch or a table clock. They use a crystal oscillator and dividing technique. You need to cut off the coil winding and add two diodes (IN4148) on both the outputs (P side of it) and join the N-side to get study 1-Hz clock.Hiit is working with a single cell-- you need to level shift to TTL or CMOS in order that it is usefulsarma Quote Link to comment Share on other sites More sharing options...
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