CHAPTER 2 ■ WHERE TO OBTAIN TOOLS AND PARTSCounting Parts
Another subtle message contained in an online store is the number of parts available for a particular family
or category. If there are a lot of surface-mount capacitors listed, you can infer that enough people are buying
enough of those parts to be worth stocking them.
The amount of space given to a variation of parts can also be noteworthy. If there are twenty lines of text
dedicated to one variation of a part, but only one line of text for another part, perhaps the one-line variation
has an unnoticed limitation.
On a sad note, if your favorite parts or packages seem to be receiving less and less coverage, perhaps
something is changing in the industry. It might be worth investigating whether that particular piece of
technology is fading away.
Comparing Prices
The price list also tells a story. The chips listed in Table 2-2 all provide the identical logic function. So why
the huge range in price?
Researching the plain 7400 chip reveals that it uses the most power, provides poor high-output current, and
has no feature better than the other chips. Why is it the most expensive? Because it’s obsolete. It’s a really old
design. If you’re among the few people who still want that part, the lack of sales volume is going to cost you.
The lowest price on this list happens to be for a technology, 74HC00, that is very popular and has fully
matured. Rounding out the bell curve is the newest technology, 74AUC00, which isn’t selling yet at a high
enough volume to bring down the price.
Of course, there are exceptions. With labor-intensive or rare-material parts, higher prices may be an
indication of better quality parts rather than obsolescence or the latest technology.
Saving Money
You can spend money more efficiently by:
- purchasing in larger quantities
- ordering online rather than buying in retail stores
- looking for discounts (sometimes they’ll tweet discount codes, sales, or free shipping)
- avoiding handling fees for minimum order amounts by bundling smaller orders
- considering the shipping costs
Table 2-2. Single-Unit Prices for the Same Chip Function
Chip Price
7400 109 cents
74LS00 56 cents
74HC00 45 cents
74AC00 50 cents
74AUC00 88 cents