All Jazzed Up...

We finally started painting the house last weekend--it's been looking pretty bad for a while, especially the parts we kind of rushed through last time around. This time, rather than trying to do the whole thing all at once, we've decided to just tackle it bit by bit through the summer with the idea that we'll do a better job if we take more time. To that end, it's nice to have finally gotten started, but it's pretty depressing that we only did about 1/10th of the whole house. Granted it was the worst tenth, but still...

While scrapping all day Sunday, Tamara earned herself an impressive sunburn on her shoulder.

I got burned on my calves a little, but no where near as bad as Tamara got.

Here's a shot of the new paint job, you're not getting a before on this one, it's too embarrassing.

-Tim

AC to DC to more DC

Some coworkers are trying to write a computer program to control the effusion cell shutters on their growth chamber. Unfortunately, the computer output we have can only put out 5 Vdc, and the shutter box needs 13.5 Vdc to actuate and so they asked me to build them a box to upconvert between the two. The catch was that it couldn't run on battery power, it needed to run off the line--and I'd never done that before.

The circuit to multiply a DC voltage is farily simple, but they needed eight channels for the eight shutters, and I decided to go all out and add a cooling fan and power LED. To save time (and possibly, injury) I decided to buy a ready made power entry module--with built in RF filter, fuse box and switch--and regulated power supply--the transformer that turns the AC line voltage into the DC to power the circuit. The power supply is awesome because it's called the Power Gorilla, and it has a picture of a gorilla. Yeah, it's made in japan...

Wired circuit board--with POWER GORILLA!


Near complete box.

Assembled DC Converter.

Of course, in the long tradition of homemade electronics, it didn't really work the first time. It turned on ok, the fan and LED worked, and--most importantly--no one died and nothing caught on fire. But there was a fatal design flaw, the resistors I chose were two small, and so the op-amps could not put out enough current to generate the required 13.5 V. Luckily, it's fallen to Allison to replace all 24 resistors for me.

-Tim

Rain, Rain, Go Away...

Beyond the usual tornado scares, the last couple of days have brought a lot of ...rain... here in central Illinois. And I'm coming to realize that the public drainage systems in St. Joseph (home of the world-famous St. Joseph Animal Hospital at which I work) are completely inadequate. With the nearest parking more than a block away, we all threw on our galoshes and waded in to work. Some of our clients were more innovative.

(photos by Teri Raye)

-Tamara