Eagle Schematics -- when to split up? and general pointers..

I'm a beginner and today I tried taking a Fritzing breadboard across to a Eagle PCB (attached). I went through a few iterations and this is where I am now. I was wondering if some experienced users of Eagle could give me some pointers on how to improve this?

How much should the schematic be split up? This latest iteration involved splitting up the schematic into multiple pieces, as it seemed to be the Eagle way of doing things. Have I overdone it? Underdone it? Is there are a rule of thumb for this?

With orientation. is there a convention for whether names / values / labels should be at the end of nets, running alongside them, horizontal, vertical, etc.?

Anything else you would do differently?


Place your loads in the collector path of the TIP122s.

Although it was quite annoying just because that's the nature of Dave Jones, and especially annoying because it could have been 1000% better with 5% more effort on Dave's part to do it properly instead of half-assed (as usual), I found this video to be really educational: https://www.youtube.com/watch?v=R_Ud-FxUw0g I haven't stumbled across this sort of thing before. I think the "here's the wrong way to do it, here's the right way to do it, this is why" approach worked well. Maybe there is a far better guide someone can suggest that doesn't require sitting through a 1.5 hour video?

I put schematics like that together all the time. Way easier to follow vs lines running all over the place. Be sure to use the error checking to make sure nets have the same names, I've hosed myself a couple of times with a typo that left a signal unconnected. Use error checking on both the schematic and then on the board layout.

And sourcing current like that from a TIP122 will not yield good results. That's an NPN setup, it wants to sink current to GND. You want a PNP setup if you are going to source current.

Thanks for the helpful comments. pert this link looks like it will answer a lot of my questions on how to make things look clean and a bit more 'industry standard'.

To clarify the issues with the TIP122s. I bought these earlier this week after my BC337 NPNs couldn't power the fan or buzzer. They seem to be working ok but if I understand the comments the correct way to use the TIP122 is for the load (e.g. fan, buzzer) to be in the same path as the collector of the TIP122, and for the emitter to connect to ground? If so, I'll have to go and think about this as currently the GND for each load is connected to GND.

I’ve made changes to the TIP122’s to incorporate the suggestions earlier. I’ll have to do some more reading to understand why it’s better this way.

Also just generally tidied up and implemented some of the ideas from the 30 min or so of the youtube video posted above. Feels like an improvement from yesterday?

Thanks for your help!

Combo: pert this link looks like it will answer a lot of my questions on how to make things look clean and a bit more 'industry standard'.

I'm glad if it was helpful. Dave Jones certainly has a lot of knowledge and doesn't mind sharing it. I also find him quite entertaining in small doses. My favorite Dave Jones content is the interviews he does on the excellent Amp Hour Podcast, though I skip over the episodes where it's just Chris Gammel and Dave chatting because those usually have some Dave Jones rants.