Power header

October 7, 2010 9:41:27 PM CDT

More power distribution stuff.. this time we have a set of power rails. The breakout boards from the previous article are all well and good, but power has to come into a circuit from somewhere.

I happen to like using barrel jacks for my DC power connections. They're rugged, they're compact, they're easy to use, they isolate power and ground so you can't short your power supply with a loose screwdriver, and they're cheap. Better still, most wall warts already come with one.

Like I said when discussing the power breakout boards, the rails along the sides of a traditional breadboard do their job well. They may not be perfect for all applications in haystack circuit construction, but for just grabbing power, it's hard to beat a row of ports with Vcc and GND running side by side.

This board combines the two: barrel jack and power rails.. and an indicator LED.

(yeah, yeah, I throw LEDs on pretty much anything that carries power. spend ten minutes with a voltmeter trying to figure out why your circuit just stopped working, only to find a power line that's come loose somewhere upstream, and tell me they aren't worth the 5c and 15 seconds it takes to hook one in)

There's no bounce-prevention cap on this board, and for the life of me, I can't think why. Consider this power header v1.0 [obsolete], and give me a while to come up with an improved version.

There isn't much else to say about this board. It falls more under 'electrical wiring' than 'electronics', so there's very little subtlety to discuss. The only thing even vaguely interesting is the current limiting SMT resistor on the bottom of the board, and I can't even spin that out to more than a couple of dozen words.