Digital counter

Hi!

I am trying to create a digital counter in Multisim9. I have two 74LS47 + 74LS160 schemes connected to a pair of 7-segment display. My counter is counting from 00 to 99 and continues without stopping.
My questions are: how do I make it stop after it reaches 99 and how do I make it count backwards?

I will appreciate any help

up

untitled said:

Hi!

I am trying to create a digital counter in Multisim9. I have two 74LS47 + 74LS160 schemes connected to a pair of 7-segment display. My counter is counting from 00 to 99 and continues without stopping.
My questions are: how do I make it stop after it reaches 99 and how do I make it count backwards?

I will appreciate any help

Click to expand...

The first part is easy connect carry out to the appropriate enable pin. The second isn't, you need to ditch the '160 counter. Try a 74HC193.

BTW your files are useless to anyone without multisym.

Ubergeek63 said:

The first part is easy connect carry out to the appropriate enable pin. The second isn't, you need to ditch the '160 counter. Try a 74HC193.

BTW your files are useless to anyone without multisym.

Click to expand...

Here is the image of my circuit. Unfortunately there is no 74HC193 in multisim, I don't understand what to replace it with.

untitled said:

Here is the image of my circuit. Unfortunately there is no 74HC193 in multisim, I don't understand what to replace it with.

Click to expand...

Well the quick answer is maybe it is an eval and they only gave you LS parts and only a few of those, try 74LS193.

The other possibility is to pick up a spring board from Radio Shack and just wire one together.

You need to look for a BCD up/down counter for what you are trying to do. 74190,192,193,40192,40110 are all candidates. The letters in front, middle and end of these numbers are manufacturer, family and package designations.