Summary/Intro (skip to Bottom Line for quick problem description):
I am building a circuit that only needs to count for 8 hours. As typical, the circuit must be as cheap as possible. The circuit should hold the state as to how many hours have elapsed (i.e. have an output pin high for 1 hour, 2 hour, etc) - I can use a simple small decade counter to hold that state. The more difficult part is counting the hours. It seems to me that counting hours should be a common requirement. I have examined counting circuits based on quartz crystals verses 555 timers and op amp square wave generators. I like the idea of the quartz crystal much better as it requires less external parts and seems more simple and cheaper. The problem is that it requires a ridiculous ammount of counters to divide say a 1Mhz crystal or even a 10Khz crystal down to 1/3600.
Bottom Line:
So, what is the industry standard cheapest way to build an hour counter?
Thanks!
Zan
I am building a circuit that only needs to count for 8 hours. As typical, the circuit must be as cheap as possible. The circuit should hold the state as to how many hours have elapsed (i.e. have an output pin high for 1 hour, 2 hour, etc) - I can use a simple small decade counter to hold that state. The more difficult part is counting the hours. It seems to me that counting hours should be a common requirement. I have examined counting circuits based on quartz crystals verses 555 timers and op amp square wave generators. I like the idea of the quartz crystal much better as it requires less external parts and seems more simple and cheaper. The problem is that it requires a ridiculous ammount of counters to divide say a 1Mhz crystal or even a 10Khz crystal down to 1/3600.
Bottom Line:
So, what is the industry standard cheapest way to build an hour counter?
Thanks!
Zan