[sdiy] frequency counter

[mark verbos]

well 5 is easy. You can do that with a 4017. But what about 100? You 
could do one of those where you send the outputs from a 4040 to some 
gates to make it reset when it gets to a certain count, but I thought 
maybe there was some magic. Maybe the custom crystal IS the answer. How 
much do they cost?

Mark

Scott Gravenhorst wrote:

>mark verbos <mverbos at earthlink.net> wrote:
>  
>
>>How do you ddivide by 25,000? Aren't all counters powers of 2?
>>    
>>
>
>There are circuits that can divide by numbers other than powers of 2.  I
>figured out a circuit for a symmetrical output divide by 3.  For 25,000, you
>will need divide by 5 and divide by 2 as they are the two prime factors of
>25,000.  Ring counters are one way, JK flip flops with special logic
>interconnections is another.  
>
>I wouldn't mind knowing of a reference of different non-binary power counter
>circuits, especially ones with symmetrical outputs.
>
>  
>
>>Mark
>>
>>
>>
>>Magnus Danielson wrote:
>>
>>    
>>
>>>From: mark verbos <mverbos at earthlink.net>
>>>Subject: Re: [sdiy] frequency counter
>>>Date: Sat, 26 Jun 2004 21:22:36 -0400
>>>Message-ID: <40DE215C.3000700 at earthlink.net>
>>>
>>> 
>>>
>>>      
>>>
>>>>Ian Fritz wrote:
>>>>
>>>>   
>>>>
>>>>        
>>>>
>>>>>Sure.  When I set up a patch for recording I just zero-beat the VCOs 
>>>>>in against my xtal-derived A440.  And since I have carefully taken out 
>>>>>all the drift in my VCOs I never have to touch the tuning again 
>>>>>(although I can't help checking once in a while, anyway).
>>>>>     
>>>>>
>>>>>          
>>>>>
>>>>What crystal frequency did you use to get an A440?
>>>>   
>>>>
>>>>        
>>>>
>>>I was thinking the same thing.
>>>
>>> 
>>>
>>>      
>>>
>>>>I have been tinking about this over the last week and haven't seen any that
>>>>seemed right for it.
>>>>   
>>>>
>>>>        
>>>>
>>>However, I came to realize that 11 MHz isn't that unusual. Just divide by
>>>25000 and you are home free!
>>>
>>>Cheers,
>>>Magnus
>>>
>>> 
>>>
>>>      
>>>
>
>---------------------------------------------------------
>- Where merit is not rewarded, excellence fades.
>- Hydrogen is pointless without solar.
>- What good are laws that only lawyers understand?
>- The media's credibility should always be questioned.
>- The only good terrorist is a dead terrorist.
>- Governments do nothing well, save collect taxes.
>
>-- Scott Gravenhorst | LegoManiac / Lego Trains / RIS 1.5
>-- Linux Rex         | RedWebMail by RedStarWare
>-- FatMan: home1.gte.net/res0658s/FatMan/
>-- NonFatMan: home1.gte.net/res0658s/electronics/
>-- Autodidactic Master of Arcane and Hidden Knowledge.
>
>
>  
>