This question is ultra verbose, but I'm doing this in an effort to help other newbies (like me at the moment) as they first get into a CAD program like eagle. In the past when I've been new to a field I've always appreciated when people wrote out detailed explanations that are aimed for people that don't know what they're doing yet, so I'm try to pay it forward here.
I want to ask a general question in the context of a specific problem:
I'm just starting to learn Eagle CAD and I'm trying to build up a schematic of a circuit board I've built.
I have two capacitors in my board that I'd like to add to my schematic:
I know I have the following givens to identify the capacitors in eagle's library:
- They're polarized electrolytic capacitors
- They're through hole components
- They're radial capacitors
- I know each of their diameters
- I know each of their values (though that seems to be moot when finding the component in the library)
When I look through the eagle libraries I can narrow down my choices a bit based on what I know about the components:
But I'm not sure how to find the right component from here.
- I know the names seem formulaic, so is there a particular naming convention of the components that I can use to search?
- Am I even going the right way about finding these components?
- And I'm talking about these specific capacitors at the moment, but I have the same question about finding components within the libraries in general. How should I go about identifying the library component for physical components I have on hand?
UPDATE: More detail based on the feedback
I immediately got helpful feedback so thank you Eugene, awjlogan,and Steve (and other people that may reply with helpful info in the future).
To help other newbies in the future I thought I'd add a bit more detail about this specific scenario based on the feedback I got.
Vendor specific naming
In my opinion, one of the most helpful pieces of feedback is knowing that the naming conventions are vendor specific and change from library to library.
I find this helpful because it makes me feel a bit less lost when looking through all of the possibilities. When I first started looking I felt like there were secret languages and meanings that I didn't know (and there are), but knowing that these change from vendor to vendor makes me better about it because there isn't some ultimate secret convention that everyone but me knows that I need to figure out, I just need to get to know how various vendors identify their own parts.
I don't know if that's helpful, but it def made me feel better about it.
Looking to the datasheet for the naming convention
This kind of fits into the vendor specific naming, but I wanted to call it out in a different heading.
I should be able to look to the datasheet or catalog for naming conventions and identification.
In this case the capacitors came in a kit that didn't come with a datasheet and I'm not able to find one online, but knowing that I should look to the datasheet for this kind of information will be helpful when I start looking for other part footprints like the buck converter and stepper motor driver that I'm going to add in a bit.
I'm sure this is another "no duh" fact for experienced people, but as a newbie it wasn't immediately obvious.
A piece I was missing from my list of identifiers above when looking for the component in the library was the pin spacing for the through hole component (facepalm). It's obvious once I read the feedback, but initially I didn't think of that as a variable to include.
These exact spacings should be taken as rough when it comes to looking in the library it seems, so we're just looking for close matches.
The anatomy of a specific naming convention
Pulling from awjlogan's answer:
Every EDA package will handle its library differently and also, within the tool, it's likely the libraries are not consistent. In the CPOL library in Eagle, you can see in the 'Description' column things like 'E5-8.5' - this corresponds to a radial capacitor, 5(.08) mm pin spacing, and 8.5 mm outer diameter. So, in this particular library it is: E[pin spacing]-[diameter]', with dimensions in mm. You've searched as far as you can, so you just need to select manually now.
This breakdown is ultra helpful when it comes to looking at the names. I knew that the names had a pattern and meaning, but I wasn't sure how it shook out, so knowing that in this library's case the different sections of the names correspond to the common identifiers for the part (and knowing what those common identifiers are). I'm sure if I step through several libraries looking at the equivalent parts I'd be able to parse out the way they embed meaning into their part names.
The specific component doesn't matter much if you're only doing a schematic
This is also a helpful point to know. In this case I am planning on taking the plans over to my local maker workshop and milling out a circuit board so the footprint does matter, but it's good to know that if all I'm planning on drawing out is a schematic the specific component in the library doesn't matter as much. That takes some pressure off.
The components I picked
Based on what I knew before and what I know now I picked the following parts.
I think/hope these are the correct pics (def let me know if I picked incorrectly).