Ni Multisim Counter 199 I have made a counter which counts f

Ni Multisim Counter 1-99

I have made a counter which counts from 0 to 99.

Because i was lazy i built up the project with a frequency generator (so i did not have to smash the key of a switch)

However now that the counter is finished i would like to remove the frequency generator and make the counter increase by 1 everytime i toggle the switch (space)

Any suggestions?

R3 U2 0A. 13 O2 QB OC. D. QB. OC. OD. XFG1 ENP ENT RCO. OF KeySpace RBL BI/RBO. LOAD CLR 74L S47N 2CLK 74HC160N 6V A B CDEFG AB CDEFG R10 U1 U4 R1 10k OB. oC. OD. OE. OF. OG. QB. QC. QD RCO. 1s RBL BI/RBO. ENT Key: A 9LOAD CLR 74LS47N CLK VCC 5.0V 74HC160N 6V 5.0V

Solution

The proposed 00-99 digital counter becomes very handy in places where you need to keep the people organized in some specified order.

Operating details of the digital counter

As may be referred the circuit employs the popular 555 IC to genearte the pulse clocks. The pulse counting is done with the help of SW1. A couple of CMOS ICs 4026B respond to these clocks and become directly responsible for running the 7-segment display.

Since the last digit is restricted to 99, the first 4026 activates the second, when it crosses from 9 to 0. (see the pin 10 of the first 4026 that enters the clock input of the second).

When the circuit is first powered, it may not start its count from a zero, so a momentary reset activation becomes necessary and is implemented using the switch (SW2). Pressing this switch the account resets the circuit and starts the count from zero (00).

It may be interesting to see that a pulse is applied to pin R \"RESET\" in each integrated circuit.

A counter is a digital sequential logic device that will go through a certain predefined states (for example counting up or down) based on the application of the input pulses. They are utilized in almost all computers and digital electronics systems [1].

There are two main types of counters: Asynchronous and Synchronous counters. We will examine both below and implement them using JK Flip-Flops in NI Multisim.

The 74LS90 integrated circuit is basically a MOD-10 decade counter that produces a BCD output code. The 74LS90 consists of four master-slave JK flip-flops internally connected to provide a MOD-2 (count-to-2) counter and a MOD-5 (count-to-5) counter. The 74LS90 has one independent toggle JK flip-flop driven by the CLK A input and three toggle JK flip-flops that form an asynchronous counter driven by the CLK B input.