Digital counter

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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

 

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up

 

[Ubergeek63]

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

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.

 

[untitled]

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.

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

 

[Ubergeek63]

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

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.