Urgent!!please Help

Thread Starter

razzler

Joined Feb 9, 2008
16
any one who can help is greatly appreciated. the simulation for the lamp handball experiment which is the basis for our real project is not working. It's done in multisim and i'm at wits end. I just can't get it to run and i'm a total beginner in using multisim. i've attached the file, the logic diagram and a photo of a circuit of the said experiment but they used a 555 timer which I don't get the function in the experiment. please help. the presentation of the project is on monday and this is the only part that's not working :(

so the circuit works like this. first, it is initialized with the reset switch. the start switch starts the game by placing the ball(a probe) at the extreme right. the user must press the pulser push button to start the ball moving to the left. the single light shifts to the left until it reaches the leftmost position at which time the ball returns to the user by reversing the direction of the shift of the moving light. when the light is again at the rightmost position, the user must press the pulser again to reverse the direction of the shift. if the user presses too soon or too ate, the ball disappears and the light goes off. the game can be restarted by turning the start switch on and then off. the start switch must be open(logic 1) during the game.

i've done the rest of the connections except for the pulser part. is the use of the bus vector connector correct?i just copied it from the sample simulation of a shift register done in multisim too.
 

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hgmjr

Joined Jan 28, 2005
9,027
So, if I understand your post correctly, what you need is a circuit that will be used in the block of your diagram labeled "PULSER". Am I correct?

hgmjr
 

hgmjr

Joined Jan 28, 2005
9,027
I will have to defer your question about multisim to one of our members who uses the product.

However for a very thorough treatment of the 555-timer I would refer you to this link.

The manufacturer's datasheet (e.g. National Semiconductor, Texas Instruments) for the 555-timer is also full of good application information.

hgmjr
 

hgmjr

Joined Jan 28, 2005
9,027
I can see in the photo you have provided, what appears to be a 555 timer already installed on your breadboard. Are you having a problem getting it to work?

Is it not oscillating?

hgmjr
 

Thread Starter

razzler

Joined Feb 9, 2008
16
i haven't done anything yet. the photos are from a blog who did the same experiment but it only had the photos and no explanation of the circuit. from the logic diagram, there was no need of a 555 timer and compared to the ones in the photo with the timer, it confused me as to why the instructions in the experiment did not specify a timer while the one done in the photo(which worked) had a timer :(
 

JoeJester

Joined Apr 26, 2005
4,390
razzler,

I would suggest you start with one 74194 and four LEDs and make that work. Then add the second 74194. Then work your way back to you get to the set/reset flip flop. You don't need alot of those inverters, you'll see the error's in your schematic as you build the circuit.

Yes you need a clk signal and a pulser signal. Both those functions could be done by two 555 circuits or a pic.

What is your objective?
 

Thread Starter

razzler

Joined Feb 9, 2008
16
i'm suppose to be able to simulate a digital game of table tennis but to do this, I have to make the digital handball game work since it is the basis for the other one. I also have to have counters for the sets of game and the players' scores....x_X i don't really know what to do anymore
 

JoeJester

Joined Apr 26, 2005
4,390
It can be done in multisim, electronic workbench, TI-Tina, and a host of other simulators, assuming you have all the necessary models.
 

Euclidjay

Joined Oct 11, 2013
24
I have the same project Lamp Handball and have the same problem I've simulate this to multisim before doing the project. I'm surely I've follow the schematic diagram but it doesn't work. there's no output. Have you solve your problem?
 
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