Hello,

I need a 1 Hz timebase for several projects I want to do, running off DC battery power (no 60 Hz mains power to derive from). I've come across the attached circuit, from: http://ourworld.compuserve.com/homepages/Bill_Bowden/page11.htm#oscilate.gif. (I plan to use the circuit on the right in the picture), to develop a 32.768 kHz timebase which I'll divide down by 2^15, to a theoretical 1 Hz timebase with which to trigger clock pulses in a series of counters. Only problem I'm having, is the variable capacitor. I'm assuming this is to adjust the oscillator to the exact frequency, but it doesn't say anything about the range this variable trimmer should be.

So, can anyone help me with that range? Or perhaps a better / easier means of getting a 1 Hz timebase?

Thanks very much!

 

Look up the CD4060 datasheet, it will generate a 2Hz time base with the same crystal.

 

Thanks kindly!