Electronic Parts: Difference between revisions

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<h5>Some tips for component types</h5>
<h5>Some tips for component types</h5>
For '''resistors''', just write the raw value+decimal suffix. So '''100''' for 100 Ohm or '''5.6k''' for 5600 Ohm. Use the number of significant digits given on the resistor. If it is a 3 + 1 stripe resistor, these are two significant digits (e.g. '''12k'''), on a (4 + 1) stripe resistor, they are three significant digits (e.g. '''23.4k''').
For '''resistors''', just write the raw value+decimal suffix. So '''100''' for 100 Ohm or '''5.6k''' for 5600 Ohm. Use the number of significant digits given on the resistor. If it is a 3 + 1 stripe resistor, these are two significant digits (e.g. '''12k'''), on a (4 + 1) stripe resistor, they are three significant digits (e.g. '''23.4k'''). If you know the tolerance of the resistor (gold = 5%, brown = 1%), then add it in the description field.


For '''capacitors''', write the value + unit (pF, nF, uF -- with 'u' being used for 'micro'). So '''2200uF''' or '''100nF'''. Use the Search tab to find other capacitors (Usually just typing 'cap' in that search field will narrow it down enough).
For '''capacitors''', write the value + unit (pF, nF, uF -- with 'u' being used for 'micro'). So '''2200uF''' or '''100nF'''. Use the Search tab to find other capacitors (Usually just typing 'cap' in that search field will narrow it down enough).

Revision as of 11:27, 3 October 2015

Electronic Parts at Noisebridge

We have a lot of donated parts, but they are currently badly to not organized. Until they are, this page describes the project to organize them.

Organization Project

The organization effort are divided into several phases. The goal is to have a system that allows us to have various people work independently whenever their schedule permits.

Phases Overview

  1. Numbering. We number all filled drawers as they are now in the cabinets. The number helps us associate these with the components they contain to enter in the database. Status: good chunk done (Douglas did the bulk of it).
  2. Entering in Database
    1. Take pictures of interesting components. Many pictures have already been taken and associated with the number on the drawer.
    2. Identify parts and enter them in the database (work in progress).
  3. Coalesce duplicate items in database (not started yet; requires Phase 2 to be complete)
  4. Big physical drawer re-org: Database suggests which drawers with duplicate items to put together in one bin (result of phase 3). Print labels with barcodes and put on drawers. Database suggests grouping of items but allows the manual work in meat space to do work independently for fast progress. No tedious entering of new physical locations in the system needed.
  5. We take picture of the final cabinets. Barcodes are identified in the image and system remembers position of each item. Good thing: this can be re-done whenever some other manual org has been done in meat space.
  6. A galvo-like system is built that points a laser to a component searched.
  7. Profit.

Phase 1 Numbering

TBD describe

Phase 2 ID parts

Enter parts in database

Process Batch: do {

Process in general: When on the Noisebridge network, look at http://pegasus:3000/status which numbers have not been entered yet. Decide which you want to work on and go to the electronics area and grab bunch of drawers with the numbers. Go to your computer, open http://pegasus:3000/, type in the drawer-number in the big field on top and press return. Ready to go.

Identify

Identify the parts in the drawers: choose a category (or enter a new category in the 'other' field), enter part values, description and possibly datasheet (sometimes you have to find the datasheet to know what something is. Use OctoPart, DigiKey or Mouser to help. If you have a datasheet URL, copy it in the appropriate field).

Once you submit this form, you are automatically placed to the next number, which makes entering quick.

Some tips for component types

For resistors, just write the raw value+decimal suffix. So 100 for 100 Ohm or 5.6k for 5600 Ohm. Use the number of significant digits given on the resistor. If it is a 3 + 1 stripe resistor, these are two significant digits (e.g. 12k), on a (4 + 1) stripe resistor, they are three significant digits (e.g. 23.4k). If you know the tolerance of the resistor (gold = 5%, brown = 1%), then add it in the description field.

For capacitors, write the value + unit (pF, nF, uF -- with 'u' being used for 'micro'). So 2200uF or 100nF. Use the Search tab to find other capacitors (Usually just typing 'cap' in that search field will narrow it down enough).

For transistors, ICs etc. write the component value such as 74LS132.

Some component types don't have a value or something, they need a more free-form value, e.g. 8 Pin header, 0.1"

If the component cannot be determined, check the ? MYSTERY category, so that it is easy to find for someone to have another look.

If the box is empty, just write 'empty' in the name/value.

Footprint

In the Footprint field, enter the footprint of the part if you know it; Not so much for resistors or capacitors (though distance of leads might be useful: e.g. 7.5mm) Search for TO220, TO-92 or TO-3 for pictures of common transistor footprints to familiarize. Dual-in-Line cases (almost all ICs we have there), are typically abbreviated DIL-something, e.g. DIL14 or DIL16 (for 14 or 16 pins).

Description

In the Description field, add a one line description if it is an IC (e.g. Dual Schmitt-Trigger, you find these in the datasheet). For components such as resistors, capacitors or transistors it is good to have some semi-structured way to enter additional parameters of the part, such as Ice=5A, Uce=50V for transistors or P=0.25W for resistors, U=16V for aluminum capacitors. You find these values in the datasheet if you had to search for the part online. If you do electronics, ask yourself what you would like to be able to search for to narrow down to a set of components (I will make searching ranges possible later). Use the Search tab to find examples; e.g. search for '2N' to get examples for transistors or 'P=' for resistors that have this value set.

Notes

Put in notes things that are not really component related, but something like 'needs picture' if it is a really strange part that would be better with an image.

} while (!tired_yet)

Return the drawers back to where they came from and take the next batch. Repeat until tired :)

If there are multiple components in a drawer

If you find a drawer that has one number, but there seem to be multiple components inside, we need to separate them, because there is only one ID per component. If it is only a few stray components between the 'real' components, just sort them out and keep in a mixed-parts drawer -- we can take care of that later, no reason to waste time on this one yet.

If the there are more than a few stray components, it makes sense to separate them and put in a separate drawer. Use a drawer that already has a label but is empty - you find them on the status page (they are crossed out), or by searching for it. Put the components you want to separate in that drawer and change the entry in the database from 'empty' to the new value.

(If there are no empty drawers with a label left, take a new empty drawer and put a blue tape sticker on it, and just put the component inside - we can label and put in the database later)

Take pictures

Henner has some set-up which he uses to take pictures right now, but this is one-off for now. We plan to have a dedicated photo-box (maybe using the book-scanners) to do so.

Phase 3 and following

Will be interesting after Phase 2 completes