[sdiy] frequency counter

[Scott Gravenhorst]

mark verbos <mverbos at earthlink.net> wrote:
>well 5 is easy. You can do that with a 4017. But what about 100? 

Input divided by 5, that divided by 5, that divided by 4.

I hadn't thought of looking at a decade counter for a clue.  Thanks.

>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.
>>
>>
>>  
>>
>

---------------------------------------------------------
- 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.