BCD counter with LED's

[Viper5]

Hello. I am new to the forum. As the title suggests, I would like to design an asynchronous simple 4-bit BCD counter with LED's. From what I understand, I will need 4 J/K flip flops (1 for each bit), 4 led's, a battery, and then possibly some resistors. Also, I may consider also adding a synchronous counter switch so I can go from sync to async if it's not too much trouble. Any help would be awesome. I'm not a big fan of radio shack, but I will go there if I have to.

EDIT: As a side question, does the clock inputs have to be at a certain frequency or can it just be a switch that you control up and down for 1 and 0?

[pebe]

Assuming what you want is to count individual pulses and output the count in BCD rather than in binary, then the simplest setup would be to use one half of a CD4518 dual counter.

You can then take its BCD output and feed it into a CD4511 which will convert the BCD into 7segment outputs capable of driving a 7segment LED display directly (using inbuilt drivers).

You can read up on these ICs by getting the datasheets from here:

http://www.datasheetcatalog.com/

I hope that helps.