circuit simulator - Electronic Circuits Projects Diagrams Free

mayankguru · 21st September 2007, 05:21 AM

hi everyone,
i have made first circuit of my life,i was very excited while making it.but really depressed after i saw that it deostn,it works the way it should.
this is the link to the circuit
http://www.mediafire.com/imageview.p...yz3dh0&thumb=4

wat this circuit is doing
http://www.mediafire.com/?3wa9wzmbztx
.................................
its simply tells which out of the 16 switches is pressed first. .
i have connected LED's on the putput terminal of the IC2 (Dmux)
and neither of the LED lites up when any of the switch is turned on. . .
what i think is that there might b some connection which is missing in the circuit might b the connection from ic4 to ic3. . or do i have to connect +5 volt to IC1 on its 24th pin

2nd question is that can some one suggest me a circuit simulator for
this circuit. . .
pls help

audioguru · 21st September 2007, 03:51 PM

Why don't you attach the schematic "up side up" here, instead of posting it sideways on a different website?

Show how you connected your LEDs.

mayankguru · 21st September 2007, 04:54 PM

Quote:

Originally Posted by audioguru

Why don't you attach the schematic "up side up" here, instead of posting it sideways on a different website?

Show how you connected your LEDs.

i connected the +ve terminal of led to the positive of battery and negative terminal to the output pin(any of the 16) of IC2. .the led lites up only wen connected with the pin 12 of ic2. .

audioguru · 21st September 2007, 05:54 PM

I have never seen a 5.0V battery. What is its voltage?

The max allowed output current of a 74LS154 is only 8mA. An LED without a series current-limiting resistor is like a dead short and probably the outputs and the LEDs are blown up.

I cropped your huge schematic and attached it here.

audioguru · 21st September 2007, 06:10 PM

Wait a minute.
You connected the negative of an unknown battery to the output???
You never connect a voltage to an output.

The positive of a 5.0V power supply connects to the positive terminal of the circuit and its negative connects to the circuit's ground.

ThermalRunaway · 21st September 2007, 07:53 PM

The circuit diagram you have linked to doesn't show the power supply connections (except for the 555 timer). The supply connections are assumed and so to answer your question yes, you need to connect VCC to pin 24 of IC1. You will also need to connect ground to pin 12. The same goes for the other ICs - look up the datasheets to find out what pins the power supply is supposed to connect to!!!

With regard to operation of the circuit, if you're going to connect LEDs to the outputs then you'll need a current limiting resistor. Also, be aware that the 74154 has inverted outputs. In other words, they output high normally. Personally I would suggest you use transistors to buffer the outputs of the IC.

I've had a look at the circuit and I can see how it's supposed to work. Basically the tripple-5 is going to clock the counter continuously and the mux will select each of the button's in turn. It does this very quickly so that as soon as you press a button the output of the mux goes high. This is inverted with a NAND gate (setup as a NOT) which presents a low to one side of the NAND gate connected to the tripple 5. This stops the counter counting, and the Demux on the other side shows which button has been pressed.
Only trouble is, as soon as you release the button the counter will start up again won't it? Which means you only see what button was pressed for as long as you hold the button down?

Someone please correct me if I'm wrong - because that seems a bit pointless!!!

Brian

ThermalRunaway · 21st September 2007, 09:44 PM

I simulated the circuit in multisim and it ran exactly as I described in my previous post. The only difference between that circuit and my simulated one is that I used a 7493 instead of a 74193 (because the 74193 wouldn't work for some reason)

The circuit works, but it only shows you which button has been pressed for as long as you hold the button. Therefore, it will only show you which event occured first as long as the original event stays valid.

Brian

audioguru · 21st September 2007, 09:53 PM

A 555 is a 555, not a triple 5.
A logic inverter is a logic inverter, not a not gate. A logic inverter isn't a gate because it doesn't gate anything. It just inverts.

The stupid circuit doesn't have a latch to remember which button was the first one depressed??? Then it is a very stupid circuit.

mayankguru · 22nd September 2007, 04:47 AM

Quote:

Originally Posted by ThermalRunaway

I simulated the circuit in multisim and it ran exactly as I described in my previous post. The only difference between that circuit and my simulated one is that I used a 7493 instead of a 74193 (because the 74193 wouldn't work for some reason)

The circuit works, but it only shows you which button has been pressed for as long as you hold the button. Therefore, it will only show you which event occured first as long as the original event stays valid.

Brian

thanks for ur concern Brian
u said to use 7493 instead of 74193
ok so i will change the counterIC
and for buffer i will be using 4013 (D flip flop)
can u pls mail me the working .sch file which u made at
my email jiitmayank@yahoo.com
its urgent as i hav to submit the project in college ASAP

ThermalRunaway · 22nd September 2007, 07:25 AM

Quote:

Originally Posted by audioguru

A 555 is a 555, not a triple 5.
A logic inverter is a logic inverter, not a not gate. A logic inverter isn't a gate because it doesn't gate anything. It just inverts.

I've always called a 555 a "triple-5-timer". I don't see any problems in calling it that personally. I do see your point about the "Not Gate" though. You're right, it's not gating anything (there's a pun in there somewhere), so yes a logic inverter is probably the more correct name to use for it.

I thought *I* was pedantic AudioGuru!!!

Quote:

Originally Posted by mayankguru

u said to use 7493 instead of 74193
ok so i will change the counterIC

I am not suggesting you should use a 7493 instead of a 74193 in practice. The only reason I changed to a 7493 was because, for some reason, the 74193 model within multisim didn't want to work. I spent about 40 minutes messing about with it but couldn't get it to count so I substituted it for a 7493 which, when you link both sides of the device together, does the same thing as far as your circuit is concerned.

Please find attached the working circuit. It's a multisim 8 file (zipped up) so you'll need a copy of multisim 8 before you can use it. I substituted push buttons for normal throw switches, and I've named them A-P so when you simulate the circuit you can press a letter on the keyboard from A-P and, after some time (the circuit is MUCH slower in simulation!) the relevant indicator will light up. Press the key again to release the switch and the indicator will go out.

I still don't see what practical use this circuit has - I'd be interested to find out what you intend to use it for?

Brian

ThermalRunaway · 22nd September 2007, 07:29 AM

Quote:

Originally Posted by ThermalRunaway

The circuit works, but it only shows you which button has been pressed for as long as you hold the button. Therefore, it will only show you which event occured first as long as the original event stays valid.

Brian

I need to make a slight correction in what I've implied there. The circuit WILL show you which event occured first as long as the original event stays valid OR other events occur after it. But as soon as all events have cleared, you will lose the information regarding the first event.

Brian

mayankguru · 22nd September 2007, 08:12 AM

Quote:

Originally Posted by ThermalRunaway

I still don't see what practical use this circuit has - I'd be interested to find out what you intend to use it for?

Brian

actually the project is to provide a switch in each flat of a society and the main led panel at the gatekeeper room. so wenever any switch is turned on the gatekeeper will get to know which flat is calling him.
this circuit will decrease the no. of wires used

mayankguru · 22nd September 2007, 08:22 AM

Quote:

Originally Posted by ThermalRunaway

It's a multisim file 8 file (zipped up) so you'll need a copy of multisim 8 before you can use it.

Brian

can u attach the setup file of multisim8 also as i m unable to get it from internet. .

ThermalRunaway · 22nd September 2007, 09:18 AM

Unfortunately no, I cannot post the setup file of multisim 8. You will need to purchase a legitimate copy - I'd have thought your college has it installed on their machines??

If you are going to obtain Multisim 8 by illegal means, then that's your bag and I'm sorry but I can't help you with that.

Brian

Hero999 · 22nd September 2007, 10:55 AM

Quote:

Originally Posted by mayankguru

can u attach the setup file of multisim8 also as i m unable to get it from internet. .

Not without committing copyright infringement and getting banned from the forum as a result.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Latest
Power-On delay circuit	tzitzikas	General Electronics Chat	15	7th June 2007 07:48 PM
power electronics circuit analysis	ptewright	Electronic Projects Design/Ideas/Reviews	2	25th November 2006 08:16 AM
Need help about a 7805 regulator circuit !	Zarkabul	Electronic Projects Design/Ideas/Reviews	26	13th June 2005 06:07 PM
Circuit auto OFF feature after no events design	Uman	Electronic Projects Design/Ideas/Reviews	2	3rd May 2004 05:34 AM
Circuit functioning very strange. Why?	Cyclone	Electronic Projects Design/Ideas/Reviews	12	4th November 2003 12:30 AM

21st September 2007, 05:21 AM	(permalink)
mayankguru	circuit simulator hi everyone, i have made first circuit of my life,i was very excited while making it.but really depressed after i saw that it deostn,it works the way it should. this is the link to the circuit http://www.mediafire.com/imageview.p...yz3dh0&thumb=4 wat this circuit is doing http://www.mediafire.com/?3wa9wzmbztx ................................. its simply tells which out of the 16 switches is pressed first. . i have connected LED's on the putput terminal of the IC2 (Dmux) and neither of the LED lites up when any of the switch is turned on. . . what i think is that there might b some connection which is missing in the circuit might b the connection from ic4 to ic3. . or do i have to connect +5 volt to IC1 on its 24th pin 2nd question is that can some one suggest me a circuit simulator for this circuit. . . pls help

21st September 2007, 03:51 PM	(permalink)
audioguru	Why don't you attach the schematic "up side up" here, instead of posting it sideways on a different website? Show how you connected your LEDs. __________________ Uncle $crooge

21st September 2007, 06:10 PM	(permalink)
audioguru	Wait a minute. You connected the negative of an unknown battery to the output??? You never connect a voltage to an output. The positive of a 5.0V power supply connects to the positive terminal of the circuit and its negative connects to the circuit's ground. __________________ Uncle $crooge

21st September 2007, 07:53 PM	(permalink)
ThermalRunaway	The circuit diagram you have linked to doesn't show the power supply connections (except for the 555 timer). The supply connections are assumed and so to answer your question yes, you need to connect VCC to pin 24 of IC1. You will also need to connect ground to pin 12. The same goes for the other ICs - look up the datasheets to find out what pins the power supply is supposed to connect to!!! With regard to operation of the circuit, if you're going to connect LEDs to the outputs then you'll need a current limiting resistor. Also, be aware that the 74154 has inverted outputs. In other words, they output high normally. Personally I would suggest you use transistors to buffer the outputs of the IC. I've had a look at the circuit and I can see how it's supposed to work. Basically the tripple-5 is going to clock the counter continuously and the mux will select each of the button's in turn. It does this very quickly so that as soon as you press a button the output of the mux goes high. This is inverted with a NAND gate (setup as a NOT) which presents a low to one side of the NAND gate connected to the tripple 5. This stops the counter counting, and the Demux on the other side shows which button has been pressed. Only trouble is, as soon as you release the button the counter will start up again won't it? Which means you only see what button was pressed for as long as you hold the button down? Someone please correct me if I'm wrong - because that seems a bit pointless!!! Brian __________________ --------------------------------- Electronics Test Development Engineer ---------------------------------

21st September 2007, 09:44 PM	(permalink)
ThermalRunaway	I simulated the circuit in multisim and it ran exactly as I described in my previous post. The only difference between that circuit and my simulated one is that I used a 7493 instead of a 74193 (because the 74193 wouldn't work for some reason) The circuit works, but it only shows you which button has been pressed for as long as you hold the button. Therefore, it will only show you which event occured first as long as the original event stays valid. Brian __________________ --------------------------------- Electronics Test Development Engineer ---------------------------------

21st September 2007, 09:53 PM	(permalink)
audioguru	A 555 is a 555, not a triple 5. A logic inverter is a logic inverter, not a not gate. A logic inverter isn't a gate because it doesn't gate anything. It just inverts. The stupid circuit doesn't have a latch to remember which button was the first one depressed??? Then it is a very stupid circuit. __________________ Uncle $crooge

22nd September 2007, 09:18 AM	(permalink)
ThermalRunaway	Unfortunately no, I cannot post the setup file of multisim 8. You will need to purchase a legitimate copy - I'd have thought your college has it installed on their machines?? If you are going to obtain Multisim 8 by illegal means, then that's your bag and I'm sorry but I can't help you with that. Brian __________________ --------------------------------- Electronics Test Development Engineer ---------------------------------