Ferrite beads (L1 in the photo) filter high frequency power supply noise by converting it into a tiny amount of heat. Power supply noise can cause various problems for many parts, especially in analog audio and display circuits.

Ferrite beads are simple, but choosing one can be confusing because they’re not commonly used by hobbyists. Most designs will still work if you omit the ferrite bead(s), but beads are so cheap there’s no reason to sacrifice the added reliability they provide. We describe how we pick ferrite beads for our projects after the break.

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DIP through-hole chips are an old package with instantly recognizable dual in-line pin rows.  Beginners love these chips because they’re large and look easy to solder; we abhor them because we hate messing around with the drill. Whatever your motivation for using a through-hole chip, use a socket whenever possible. A circuit board with socketed chips is easy to test without endangering the parts, and ICs can be removed, tested, and replaced, without resorting to a soldering iron. This week, by request, we looked at several common through-hole chip sockets. Read the rest of this entry »

Electronics parts can be a pain to choose. It’s often hard to tell from manufacturers’ datasheets if a part will fit your design. We auditioned six different tactile switches to find a cheap button to use in upcoming projects. A tactile switch, also called a momentary button or push-to-make switch, is commonly used for input and microcontroller resets. This type of button creates a temporary electrical connection when pressed.

Footprints for most of these buttons are available in the Cadsoft Eagle library switch-tac, or in the Sparkfun parts library under TAC_SWITCH. Buttons in the image above are discussed from left to right. Read the rest of this entry »