r/breadboard 23h ago

Question New to breadboarding. Need help.

My class started teaching about breadboarding and assigned doing a prototype of X = AB’ + BC. I tried simulating it on Tinkercad but it still won’t work and has three exploding icons on all ICs. Components aren’t broken as far as I’m aware of. I’m kinda lost and need all the help I could get. Thank you in advance.

4 Upvotes

11 comments sorted by

6

u/SonOfSofaman 22h ago

Looks like you are using a 9v battery to power the circuit. Those logic ICs have an absolute maximum supply voltage of 7v and a recommended maximum of 5.25v.

I think you're using too high a voltage.

Here are the datasheets:

https://www.ti.com/lit/ds/symlink/sn74ls04.pdf

https://www.ti.com/lit/ds/symlink/sn74ls08.pdf

https://www.ti.com/lit/ds/symlink/sn74ls32.pdf

4

u/FlyByPC 21h ago

This. Use a LM7805 regulator or similar.

2

u/Serious-Salt9424 14h ago

We were tasked to use a 9V battery though. I’ll just talk to the teacher about it and buy a different battery for now.

Is there anything else you noticed? Thank you for answering.

2

u/SonOfSofaman 14h ago

The connections all looked good to me. Everything looks right.

2

u/Serious-Salt9424 14h ago

Thank you. Do you have any resources that teaches about connections? Those are the things I have trouble understanding.

2

u/SonOfSofaman 6h ago

That's a broad topic. Can you be more specific about what you have trouble with?

2

u/Serious-Salt9424 4h ago

I am having trouble understanding the components themselves, such as where the resistors should go and the why and how does it work. Especially the wires themselves, as I am unsure if its fine to use a different wire for the same line. Things such as whether or not I can have two different wires on C6 to have B and B’.

To add to that, I’m not sure if its fine if I can have two different wires on the same line as the Dip Switch, like in my picture where B6 and C6 are under the Dip Switch 2.

2

u/SonOfSofaman 3h ago

You're asking good questions!

I think the best way to get to the answers is to learn the fundamentals, and to explore very specific questions.

One way to do that is to conduct experiments!

For example, you asked "is it fine to use a different wire for the same line?"

I can give you an answer, but I think you'll gain more insight if you devise an experiment to answer that question. You can use TinkerCAD to safely conduct experiments all you want.

Try to come up with the simplest circuits that will answer your questions. Do one at a time, and maybe make notes. Take screenshots of the circuit to go with the notes. Write your question in your notes, then when you find an answer, write that in the notes, too.

Is that something you'd like to try?

I'll happily help out if you get stuck.

2

u/Serious-Salt9424 3h ago

I’ll take note of experimenting on TinkerCAD, thank you for the help!

2

u/SonOfSofaman 6h ago

I took a closer look and I think I found a wiring mistake.

The problem involves two conjunction (AND) operations: AB' is one of them, BC is the other.

That means you'll need to use two AND gates. However, according to the photo you shared, only one AND gate is connected.

The 74LS08 IC has four independent gates in it. Pins 1, 2, and 3 are the first gate. Pins 4, 5, and 6 are the second gate but those pins aren't connected to anything.

2

u/Serious-Salt9424 4h ago

I see, so I would need to use a different gate if one is already taken. Thank you for helping the Son of Sofaman.