Spiff's Electronics Notebook

Ammo Pack vs Tape & Reel (January 10, 2008)

Whether you're a kit designer, hardware reseller, small-time assembler, or stocking up for the PTH apocalypse, you will, at some point, order more than about 2000 of something. This is the point where you get a magic decision, buy components bulk packed or on a reel. There is, often, another option: the ammo pack. Let's look at how all three stack up.

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Transistors
Posted by spiffed at 9:29 PM | Comments (0)

A bigger basic H-bridge (April 12, 2005)

We just don't do small. So when it came to choosing stepper motors, I picked nice beefy 2lb bipolar beasts. Driving these has, however, turned into a bit of a problem.

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FET H-Bridge Kit Optoisolator PCB PIC Transistors
Posted by spiffed at 8:20 PM

TO-220 Hole Screws (March 16, 2005)

The holes in the tabs of TO-220 bodies fit #6 metal screws.Conveniently, the standard screws used to hold PCs together are also #6 machine screws. Be forewarned though; the thread of "floppy screws" (also used on optical drives) are different from everything else. (The former being a finer pitch.) #6-32 nuts/bolts/screws in the length of your choosing will mesh nicely with their common PC counterparts.

If you're in a hurry, a large thumbscrew and a nut can almost double the continuous power handling capacity and more then double the peak capacity (greater thermal mass) of some transistors.

As usual, if you buy the nuts and bolts from your (or someone else's) local hardware store, it's usually cheaper then buying from electronics supply houses.

FET Transistors
Posted by spiffed at 11:11 PM

Biasing a FET (March 13, 2005)

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FET Howto Transistors
Posted by spiffed at 1:55 PM