I need some help with a circuit design please help?

Question

I want to make a circuit where each time u push a button the 4 pin output would give a low value(no current) or high value(curren)
Its a simple counter device it must give out a 0000, push button then give 0001 on the pins
3 to 0 that's 4 pins and so on until 1111 then no longer add and have another button connect to substract 0001 each time the second button is push untill 0000 then stop.
But must be able to add and subtract at any time..... thanks in advance...

Answer 1

From what I can gather you just want a 4 bit binary up-down counter. LS193 is one example, there are others.



Just put push buttons, with suitable de-bouncing, on the clock up and clock down inputs, and the 4 binary outputs will count up or down between 0000 and 1111. But it won't stop at the extremes, but it will wrap around. To cause it to stop would take additional logic.



Not clear exactly what you want, and the words you use indicate you have little experience in this area. For example, the outputs are TTL logic levels, not high current / low current, which are very non-standard levels. You have to define these.

Answer 2

An old classic TTL 74LS193 BCD Modulo 16 counter IC will do that very easily. The only thing you need to be careful of is debounce the clock switches or you'll get false counts.



http://www.datasheetcatalog.org/datasheet/motorola/SN74LS193.pdf



Here's the application of the 74LS193 as the counter you want:



http://www2.hawaii.edu/~jrand/ElectricalEngineering/8%20-%20Counter/index.html

Answer 3

http://www.digikey.com/product-search/en?lang=en&site=us&KeyWords=74HCT191



http://www.youtube.com/watch?v=tmjuLtiAsc0&noredirect=1