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LM7805 in Eagle PCB

Discussion in 'General Electronics Chat' started by computer, Dec 29, 2004.

  1. computer

    computer New Member

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    Anyone know where I can get a LM7805 regulator for eagle PCB? I can't seem to find a library file on their site or on google for it.

    Also, what capacitors should I put + to GND either side of the regulator? 10nF? ceramic? which ones!?!?
     
  2. jrz126

    jrz126 Active Member

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    It all depends on the package or footprint of the 7805 that you are physically going to use, the most common is the TO-220 (kinda big with a metal tab with a large hole drilled in it sticking out of the top).
    [​IMG]

    a ceramic cap should work.
     
  3. computer

    computer New Member

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    yes, it looks like the picture.
     
  4. dave

    Dave New Member

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  5. williB

    williB New Member

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    try typing in "Regulator"..
     
  6. computer

    computer New Member

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    bah! sometimes its really hard to find what you want. Now I'm looking for an LDR and a small piezo beeper thing but can't find one of either :(
     
  7. Noggin

    Noggin Member

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    Get a data sheet for any generic 7805, many companies make them and they're all pretty much the same. Look at the packages they come in, TO-220, DPAk, SOT-23 (I think that one is right...) and pick the package that you want to use. TO-220 is the only through hole package I know of off the top of my head for the 7805. Once you pick the package, make a new part and select its PCB footprint (I assume this is how you do it in Eagle).

    There should also be a reference design in there showing what cap values should be used. Keep in mind that the reference design is flexable and may be changed due to other factors such as ripple/noise on your input line and how quickly current is demanded from your load etc.
     
  8. computer

    computer New Member

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    Hi,

    I managed to find the LM7805 I needed when I searched for "regulator" and looked through all the results - strange way of searching when it won't find it when I try LM, 7805, LM7805, etc.

    I'm now looking for a piezo and LDR.

    The circuit is a simple PIC circuit and all the diagrams I hav eseen show the LM with a 10nF nonpolarised cap from +V to GND either side of the regulation.
     
  9. Noggin

    Noggin Member

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    Can't help you with the peizo much, try www.digikey.com if you havn't already. I like their search engine.

    National semi has a nice power supply part builder too, www.national.com (I'm assuming LDR is Low Drop Regulator but I'm not certain...)
     
  10. williB

    williB New Member

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    Yeah you have to saerch by part name , not number even though they list it by number..
    thats just the way it works. :roll:
     
  11. samcheetah

    samcheetah New Member

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    i think he means light dependent resistor. if im not mistaken eagle has a footprint for an LDR. i dont remember where it is. but even if it is not there you can easily define the footprint for an LDR. its only two holes separated by about 1mm
     
  12. computer

    computer New Member

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    yeah I can't find a Light Dependant Resistor or Piezo on there at all. The Piezo I'm talking about is a little cylinder shape thing, about 1cm high, with 2 pins about 5mm apart.
     
  13. samcheetah

    samcheetah New Member

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    and thats all the data you need to define the footprint 8)
     
  14. Noggin

    Noggin Member

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    oh duh... he's talking about footprints for parts. I had it in my head that he was looking for parts that he could use :p Silly me
     
  15. computer

    computer New Member

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    well I was looking for the symbols for the schematic too.
     
  16. samcheetah

    samcheetah New Member

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    you can do that easily. just draw a circle for the LDR and the Piezo 8)

    have fun
     
  17. 0x34

    0x34 New Member

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    When all else fails, break out the calipers and create a new package in your library. I've had to create footprints for lots of odd components throughout the years. It's easy to do, ya just need to have good calipers.

    0x34
     
  18. A340

    A340 New Member

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    How To

    Is there a very simple how to written that will guide me to make my own symbols and packages with eagle

    Thanks
     
  19. 0x34

    0x34 New Member

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    It’s easy:
    1) In the BOARD editor, select LIBRARY from the menu, then select OPEN.
    2) An open dialog will appear, listing all the PARTS LIBRARIES.
    I’d recommend creating your own custom library for your own parts at this point. You can do that from this OPEN dialog by selecting the CREATE NEW FOLDER” icon in the menu bar.
    3) Select the library you want the new part in and press OPEN.
    The LIBRARY editor window opens.
    4) On the left side of the screen, there is an icon with a picture of a gate and an IC on it. If you hover your mouse pointer over it, it is called EDIT. Click it.
    5) A part selector dialog opens. At the bottom, type in the name of the new part you want to create in the NEW window. Then press PAC (you will be creating a new package for board layout purposes). Then press OK. A confirm dialog will appear. Press OK.
    6) The part editor window is now open. Create your part using the same tools used to layout a board. Use the scale to get your measurements right as you set PAD locations and diameters. Make sure you use your layers correctly.
    ABOVE ALL – Confirm your measurements are correct! Use good calipers or have the component’s specification PDF handy! You can print your board in 1:1 aspect and confirm your pins line up.
    7) When you’re done, press SAVE. Close the library editor window. Your new part will be waiting for you in the part library you put it in.

    That’s it! Happy creating!
    0x34
     
  20. Phasor

    Phasor Member

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    Eagle needs wildcards to search properly. Try search for "LM*".
     
  21. A340

    A340 New Member

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    Hi 0x34;

    Thanks for the start; I was able to make the schematic symbol fine and save it. Now I a am trying to make the package but I do not quite understand the scaling.

    How do I go about setting the scale to build a package that measure 40mm wide by 55.5mm long. With 4 round pads 1mm in dia located 2.54mm apart and the first one position 27.05mm from one end of the outline and the center line of the pad position .5mm from the edge of the outline.

    I am also looking at this page:

    http://vulcan.ece.ucsb.edu/ece189/tutorial_2_library_part.html
     

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