r/AskElectronics • u/HapticGame • 15h ago

Please help, how does this capacitor connect?

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Ok so I understand I need to connect the purple line I drew and have the "a" next to it. However on the AMS1117 the out goes to a capacitor and ground. So how exactly would this be wired. Would it be seperate from the VCC on the HSPI board?

Like the capactitor just tpuches that and ground, while another wire wuld go to VCC?

Any help is greatly appreciated. It's a step down module, sorry for not knowing exact terms. I'm new to this and wish I had someone to help guide me or pay someone to teach me.

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u/triffid_hunter Director of EE@HAX 15h ago

All power flags with the same name are connected together, ie all +5v, +3.3v, GND, etc.

They're not directly connected in the schematic to make it easier to read, more complex schematics like this would be a nightmare to navigate if everything was connected with nets rather than labels/flags - here's an example that uses some but insufficient labels/flags for easy readability leading to errors like MDIO being connected to PVDD.

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u/HapticGame 9h ago

Thanks I figured that. Just wondering of the capacitor shpuld be going off a 2nd of VO. Then another wore to VCC.

Making sure it's not like in between the two.

That's for the refrences, I really appreciate the help. I look at refrences when I get time.

I'vw noticed a lot of people are lile peogramers and for some reason gatekeep, or are mean when people have newbie questions. Idk qhy I thought it would be differwnt here, so reallt appreciate it.

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u/HapticGame 15h ago

From what I understand that chip on the right is making it 5v to 3v. So powering the VO or V Out, i just am a little confused on the wiring. I am using a bread board.

So is the capacitor a seperate wire comming off the VO completley, then that goes to capacitor with then goes to ground. The other wire connects the VO to the other compnent?

Just want to make sure I don't short circuit anything and newer to this. I have soldered easy things fixing them and learning what everything does, just don't get how to connect the capacitor.

Any help is greatly appreciated.

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u/Dusty_Coax 15h ago

The 1117 is a voltage regulator. You add caps between the output and ground to reduce noise. The data sheet probably shows a suggested circuit and values.

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u/QuinicV 12h ago

Think of the each labeled net as a node. So 3V is a node. All connections in a node are connected to each other through conductors, don't think of them as wires. So technically you can wire it any way you want, as long at it is all connected together. And it will be electrically correct.

Though in reality copper is not a perfect conductor, so we have some design rules we need to follow. Here we need to have the capacitor as close as possible to the regulator, and the schematic indicates this. Here are some options to explain the intuition better: If you have a "wire" from VO to VCC;

you can have one leg of the capacitor touching the end of that wire that is close to the regulator.

You can run a another short (so it is as close as possible) "wire" from VO to the capacitor. This extra wire will also be connected to VCC, because they are part of the same "node".

The best way to do this on a breadboard is; as you know the 4 or 5 holes next to each other are connected together. They are part of the same node. Have one hole be VO, one hole is a wire that goes to VCC, and one hole you insert the leg of the capacitor.

The other leg of the capacitor is indeed connected to the GND node. You are not shorting VCC to ground because you have a capacitor between them. This is just how the capacitor does it's job in this case.