carlynorama

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June is Eagle Month

by Carlyn Maw on June 1, 2011, no comments

So I really dislike the circuit board software Eagle… still. This is why I do a lot of my schematics in Illustrator. I like visual control.  Unfortunately visual control doesn’t really help when you’re trying to do cicuit boards – auto generating boards from schematics does. So once again I am going to relearn Eagle by attempting to make 30 boards in 30 days.

Please note there are a couple of alternatives out there, http://fritzing.org/  (with a breadboard view feature) and http://www.upverter.com/ , but they are still a bit raw and Eagle is remains the free standard. There are opensource alternatives – but not so much for the OSX.  OrCAD and Altium (formerly Protel) are two of the big heavies in the schematic capture / electronic design automation field. I, however, can’t quite swing the 5k – and again – not so much with the OSX native.

Fritzing has a great page on the EDA player run down,btw:  http://fritzing.org/about/comparison/

My big references for this adventure: SparkFun tutorials and board designs, various Instructables, vague memories of attempts in the past including Tom Kinyon’s class at CRASH space and harassing Tod, of course.

The first result: Simple TIP120 board for driving a pulsed-pull-type-solenoid. Or a one way motor. As you like.  The reason I emphasize the type of solenoid is that the parts used can stand short bursts of high current, but do not withstand full power for long peroids of time. The amperage can go up to 8 on these babies in the right senario (full volatage, no limiter) so pulsing yes, hold no.

Eagle images attached. I put the file on BatchPCB as CRASH space, although it is single sided and designed to be printable at home.

http://batchpcb.com/index.php/Products/61662

 

Some notes:

  • Part List
    • Connector Terminal Blocks: 2 Position 5.08mm Solder Straight Thru-Hole (At least 15 Amp, 16 to 26 AWG depending on what is hooking up to it, in orig project multiple colors were used)
    • The higher power load, i.e. (12-24 VDC pull type solenoid)
    • High Power Supply (lawn mower batter, etc)
    • Optional Capacitor, at least 100 uF, rated for 100V
    • TIP120 NPN Darlington Power Transistor
    • 1N4004 Diode
    • 1K Ohm 1/4 Watt resistor
    • Microcontroller circuit sold seperately…
  • The terminal block parts are 5.08 spaced terminal blocks from the con-wago-508.lbr,
  • The resistor from rcl.lbr
  • The transistor from transistor-power.lbr
  • Everything else from the latest sparkfun eagle library, including the leads to GND.
  • Capacitor is optional depending on you application and where other caps live in your circuit.
  • If you have commoned your grounds somewhere else in your circuit you only need to run one groundline to the board, either from the micro or the high power source but not both.
  • Min trace width is 0.016 to be friendly to home printing.