How-to sort a 1 pound grab-bag of small electronic components. I sort through one of the $1 grab-bags I purchased at the Austin Summer fest 2007 HAM meet up. The reason these grab-bags are cheap is that you have to do a lot of work to make the collection of parts useful. I explain my method and give the tally for the parts.
You will need a work space that is at least one foot deep and 3 feet wide. Lay down several sheets of printer paper to work on. The white background will help you find parts and you can write notes around the part piles as you go along.
You should have a desk light to give plenty of illumination. Ideally the light would have a built in magnifier glass, if not, you may need a hand magnifier. Some of the part numbers will be hard to read for us older folks. I also find that getting a close up view of the resistor color codes helps me on occasion as well. Once you have seen the “Brown” used on a few of the resistors you will get better at quickly identifying it in the future. The magnifier helps you acclimate.
You should discard any broken parts or parts with leads that are two short to use as you go through each of these steps. The culling process does not need to be done perfectly, you will see most of the parts several times so this step actually just occurs as you go.
The first step is to separate the parts into categories. Spread some of the parts on you work surface and start separating them based on what you find. I find the best way is to pick one or two types to do at a time. For example, I sifted through the pile pulling all the resistors and capacitors. Everything else went into the next pile. The process is simple and can be done quickly. Slide the part with your finger tip, it’s either a resistor, capacitor, or something to look at later. When you done with this pass you have three piles.
Put the presorted items into bin boxes for now and go back to the left over pile to sort out another category or two, in my case I did Diodes and Transistors next. I cheated a bit and created a unknown pile as I went along. If I was not sure what it was, I put it in a separate pile. I also made a Miscellaneous pile. This captured all the things that I knew but that were too few to really need further sorting.
Here are the presort results.
|Miscellaneous:||Tip jack tip, 2 pin power header, and a cable clamp|
After the presort was done, I picked a group to sort. For each group you again do a presort. Group items by size, color etc… This helps you greatly when you move to the final stages as the parts in each of these piles will likely have one or two unique values. The final sort will be much easier this way.
I separated this pile into two major groups, big and small. Then did the big diodes, almost all of them I put into a bin box marked “Power Diodes” The smaller diodes were separated by color into a few groups, typical signal diodes, green diodes and there was a blue one that stood out. I looked at the numbers on a few of the normal red signal diodes, most were 1N4148s. I put this pile into the small signal diode bin box and looked at the green and blue diodes. I could not read or find the codes online so I am not sure what these parts are. Ultimately I made a bin called Unsorted Diodes for these and other similar parts labeled “Unknown” then moved on.
The Diode tally: 71
|Small Signal||25 (1N4148)|
|Mystery||1 TO92 , 1 green (ITT 05A 05), 19 blue (84S 09 04g)|
Again sort first by size or any other distinguishable feature. Almost all the transistors were your basic TO-92 package. All but one of these parts had marks (EBC) for the emitter base and collector pins. This makes them easy to use in breadboards. Some had painted tops so those were separated out.
Eventually you get to reading the numbers and grouping them by part number. I wrote the number on the paper work surface and drew a large circle to identify the place to put them as I went though the pile. Rather then look them up online I used a DVM transistor tester to determine the type, NPN or PNP. This is all I needed to know as I keep signal transistors in one of two bins anyway.
I noticed that some transistor have low betas (for more about this term read the recent article about transistors here ) In fact one set of a specific part number had a typical beta of about 40. These are not very good transistors. Most of the others had normal betas in the 200 range and one group had betas in the 400 range. There was a single TO-92 part which over ranged my meter. This part could be something other then a BJT transistor or maybe a Darlington. I tried to look the part up online but could not find it.
I did not test each transistor. Once I knew what type a particular part number was I could move all the transistors of that type into the correct parts bin. But, I did test most and did find one that was bad. I assume it will be easy for me to spot any other bad transistors as I use them in breadboards.
The transistor tally: 53
|NPN:||36,||3 MPN2222A, 4 04S01, 4 04S51, 13 04S48, 8 04S49, 4 others|
|PNP:||16,||8 A9H-1, 5 04S30, 3 others|
1 mystery transistor that over ranges the beta measurement as a an NPN. Number on the part are 8824 G027.
By far the largest quantity of parts is 1/4 watt resistors. I decided to sort these by decade rather then try to identify each value. I started by laying out a part bin for each decade and wrote the color next to the bin on the work surface. Then one at a time, I picked a resistor and read it’s multiplier band. Read more about resistor value codes here, Reading Resistor Codes. I also found a good page with general informaiton about resistors here.
After doing a bunch this way I realized that it was taking a long time and I was occasionally dropping a resistor into the wrong bin. I would realize this and have to hunt down the resistor to get it into the correct bin. The solution was to work through the pile pulling only one decade at a time. When I did the 100K decade for example, I would slide each resistor from the main pile, if it had any yellow I would pause to see if the multiplier band was yellow, if it was move it to the output pile, if not, move it to the processed pile. When the pile was sorted this way, I would collect up all the found resistors and drop them into the correct bin.
I also found a bunch of 1% resistors and a few that I was not sure about. The 1% resistors have extra color bands. I did not bother to sort these. I made a bin for unsorted resistors and put all the special resistors there.
The Resistor Tally: 566
|0-9.9||-||0 (in Misc)|
The last category to sort is capacitors. This bag had three basic types of capacitors as seen in the picture. I first grouped the types into three piles then separated each pile by size. I have parts bins for capacitors sorted by decades and presorting them by size tends group them by decade so it’s the fast way to get done. Once you have several piles like the picture above you can check the value codes to find the correct decade value. Read more about capacitor value codes here, Reading Capacitor Codes.
The Capacitor Tally: 279
|0-999pF||0 & 1||143 & 45|
I had fun sorting all these parts but was it worth the time? Probably not. You can purchase parts kits for components like resistors fairly cheap. The parts come already sorted, ready to drop in your parts bins. Going through grab-bags is fun though. If your willing to spend the time to save a few bucks you can have a great time with grab-bags.
I found several mystery parts to identify. How about a contest where we give some details for a mystery component and award a prize to the first person that can identify and supply a datasheet link?
I would like to know of good sources for grab bags and parts kits. If you have a source, good or bad, please post it in the comments.
For my parts bins I used a Brother label maker to make simple text lables. I got to thinking that it would be nice to print up some color labels with the resistor color codes on them and even schematic symbols for some of the bins. Does anyone know of a source for a pre-made label sheet or a graphics file that can be printed on your own printer? I am working on one of these now and would hate to reinvent the wheel. Would a label sheet like this be valuable enough to work as a uC Hobby giveaway?