File request - Need help getting started with Eagle

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wayneh

Joined Sep 9, 2010
17,153
I played a bit more this afternoon and quickly ran into hurdles. The circuit I'm reproducing is this one:
https://forum.allaboutcircuits.com/threads/micro-current-electrical-stimulation-device.126578/

1. The design that uses a TI op-amp, the TLV272. There's nothing special about it I need other than rail-to-rail, but that's the exact part I use. How to I get it into Eagle?

2. The circuit I'm working on uses a CD4017 counter clocked by a 556 timer. I hate reinventing the wheel so I'm hoping someone already has this fleshed out, and maybe you can share your file with me?

3. Choices! There are so many resistors and capacitors! I'm trying to choose "standard" parts but it's daunting.

4. There's probably a bunch of questions I should ask that I don't even know about yet.
 
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MrChips

Joined Oct 2, 2009
23,945
I am an Eagle user so I will try to help where I can.

I'll start with #3 since that is a very generic one. Yes there are so many choices. It's like a kid in the candy store, or an EE choosing from the Digi-Key catalog. There is no "standard" part because everyone has a different standard.

But it's not so bad. Once you have found your right choice for R and C you learn to stick with it.
Firstly, decide if you want tru-hole or SMD.
Next pick your package style, vertical or horizontal mounting, radial or axial, wattage, lead spacing, inches or mm.
I can give you my choices.
You will have to remember which library you found your part.
 

dl324

Joined Mar 30, 2015
12,927
1. The design that uses a TI op-amp, the TLV272. There's nothing special about it I need other than rail-to-rail, but that's the exact part I use. How to I get it into Eagle?
It's the package that matters. If the pinout matches another part in the same package, use it and use the change value button to change the part number.

If there no other suitable component, just make your own. Starting with an existing component is the easiest because it saves you some work.

EDIT: It's the same pinout as just about every other dual opamp (e.g. LM358).

2. The circuit I'm working on uses a CD4017 counter clocked by a 556 timer. I hate reinventing the wheel so I'm hoping someone already has this fleshed out, and maybe you can share your file with me?
It doesn't take more than a couple minutes to place a CD4017 and 556 and connect them.

I don't have anything to share because I use an old version of Eagle and have customized my 556 to use a symbol that makes more sense.
3. Choices! There are so many resistors and capacitors! I'm trying to choose "standard" parts but it's daunting.
For quarter watt resistors, I use R-US_0207/10; that gives lead spacing of 0.4" (10mm).
4. There's probably a bunch of questions I should ask that I don't even know about yet.
If you're laying out repeated elements (like a transistor driving an LED), make one complete subcircuit and use the cut and paste buttons (think newer versions got rid of one of those buttons - one of the reasons why I don't use the newer versions) to copy and paste. Component numbers will be incremented:
clipimage.jpg
  1. You can use the mouse wheel to zoom in and out.
  2. If you print to B&W PDFs, you can avoid those silly colored screen shots.
  3. You can highlight a component by typing "show" in the command box above the drawing canvas (e.g. show R2).
  4. There are scripts that will renumber components.
  5. Set the alternate grid to half of the visible grid and you can use the ALT key to get on the smaller grid.
  6. You can create a library that contains the parts that you commonly use.
  7. You can smash components to be able to move component designator and value individually (Eagle has some in weird places).
  8. When placing multiple components from the same package, you can do a gate swap to make routing easier.
  9. You usually have to draw your own connection dots.
  10. You can rotate components or groups of components when you move them using the right mouse button. The newer versions of Eagle broke the move group (right mouse button) - newer versions require you to select the group option from the menu that pops up. They also have the grouped components moving around while you're selecting the move group option. That's one of the main reasons I use an older version.
  11. When you use the show command and have a schematic and board opened, it will highlight the component in both windows.
  12. When you're using the wire command, you can use the right mouse button to switch between modes (orthogonal, 45, all angle, etc).
 
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dl324

Joined Mar 30, 2015
12,927
Here's a schematic from 7.5.0; should be compatible with newer versions (it's up to 9.5.0 now). Didn't add any wires.

556 is in the linear library as *556.

EDIT: I just noticed that if you press the left and right mouse buttons at the same time, you get the move group option; but you still have to click on the option and the components jump to where you clicked. Still retarded...

The 556 timer symbol makes no sense either...
1612926232900.png
 

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