Simple accurate 1s oscillator?

[Sawblade]

I'm playing around building an analog style clock circuit, but I'm still missing an accurate oscillator to provide a clock pulse to drive it. Does anyone have a simple circuit that can give a steady 1hz square wave?

 

[TheOne]

You can use a crystal and divide it down or even the mains frequency (it is well controlled) 50/60Hz and divide that down.

 

[Optikon]

I'm playing around building an analog style clock circuit, but I'm still missing an accurate oscillator to provide a clock pulse to drive it. Does anyone have a simple circuit that can give a steady 1hz square wave?

Define accurate... as mentioned crystal or mains derived but those accuracies can differ by orders of magnitude so.. can you be more specific?

 

[panic mode]

crystal oscillator is pretty much standard and 32.768kHz is very common.
this can be combined with chip like 4060 (14bit binary counter with oscillator).
2^14 = 16384
32768Hz / 16384=2Hz

Is crystal driven 2Hz clock generator close enough for your needs?

**broken link removed**

 

[pebe]

Buy a cheap quartz analogue watch. It outputs a pulse to a solenoid - or similar - every second, and you could possibly utilise that.

I bought an el-cheapo one for £2.99 at LIDL, and at that price youve got little to lose!

 

[TheOne]

That is a good idea! The quartz-driven hand wall clocks may make it easier to get to the point you want to pick up the pulse and it runs of 1 AA batt.

 

[Sawblade]

Thanks for the ideas! The circuit will be used for a simple digital 12hr wall clock, so it doesn't need to be extremely accurate as long as it can keep within a minute per month.