All posts by johncohn

Friday night – overheated

Lonnnnnnng hot day today.. Went to bed at 2am last night after working in the lab.. First work call at 8:30… By the time I finished my work I looked up from my desk and it was nearly 8pm. The only good thing about that was that my office at work is almost air conditioned. It was about 80 inside.. But that was a ton better than the 102 my car thermometer told me at lunch.. It was so hot ( how hot was it .) it was sooooo hot that my iPhone disconnected from a work call 2 times because it was too hot to work. How the heck do they do it in places like Texas

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Stay cool everyone,

Nite all, nite Sam

-me

 

Thursday night – The Hole Story

I had a complicated day where nothing went quite right.. I got lots done, but nothing came out as well as it should have.. so.. by the end of the day i was pretty beat.. it was about 90 degrees, I was hot and tired and looking for something useful to do.
The looming problem of the week has been our pool. It's been losing water at rate of over 600 gallons a day .. yet we couldn't find the leak. I'd re-tighteed all the pluming and searched the sides of the pool carefully for a leak.. no luck.. Then , this morning. Diane noticed a wet spot under the deck… .. I decided to check it out.. Indeed.. the ground was wet under the deck, but there was no visible leakage form the side of the pool.. the soil was only wet in a narrow band.. so I decided to look inside. I put on some goggles and dove to the bottom.. darn.. I couldn't see well enough without my glasses.. so I stuck them on top of the goggles.. I looked ridiculous.. but at least i could see.. I searched up and down the walls of the pool.. but nothing looked obvious.. Then I started thinking about how I'd find a vacuum leak.. When I was at MIT we'd use a variety of techniques to find leaks in high vacuum systems.. we'd hook up a mass spectrometer to the vacuum system then walk around with helium tubes squirting around joints.. when the mass spec detected soemthing.. the joint you were squirting was bad. I've seen them do soemthing similar with car air conditioning systems.. thought there you use colored smoke.. and pressurize the system with it and look for smoke ..
So I asked myself.. what would work like smoke under water.. ah-ha… an idea.. I grabbed a bottle of blue food coloring and dove back in.. I squirted it around the seams.. but it just dissipated.. I tried some of the creases on the bottom… then I saw a funny discolored space.. it was right under where the ladder usually is.. BINGO.. the dye got sucked into the hole.. by the speed of it.. there must have been a pretty sizable stream of water leaving the floor of the pool about 12 inches in form the side where the wet spot was.. I felt like Sherlock Holmes !

I wanted to get a picture of it to show diane.. so I rummaged around and found gabes underwater go-pro… curses.. the battery was dead.. and i couldn't find the charger.. not to be deterred, I took the battery out and grabbed a power supply from my lab. dialed in the voltage of the battery and clipped into it.. I charged it for about 15 min.. Then I clipped it together and took this movie.. you can see the dye get sucked into the hole..

 

I found soem underwater vinyl patch , cut it out, coated it with goo.. folded it in hal then exhaled all the air in my lungs and sunk to the bottom of the pool.
I opened the patch and quickly smoothed it over the hole. Then I put a nice piece of marble on it to help i stick.. (note: The marble happened to be the splatter guard on an old urinal.. Don't know why I added that detail.. but you have to admit it was interesting 🙂

so.. I accomplished at least one useful thing today..

lets see if it holds !

nght all. night sam
-me

 

Wednesday night – wires crossed

D-oh !.. I’ve been working on and off on this great LED hoop the last couple of days and just managed to burn out the processor in it (I think). I managed to have two of the programming wires shorted and must have fried at least one of the critical programming pins in it’s poor atmel brain. I tried everythign to fix it.. but I think it’s gonna need a chip transplant.. damn.. Sometimes our wires just get crossed. I’ve got to find a better way of programming this thing. I’m too tired to fix it now.. it’s natures way of telling you to give up.. at least for awhile. More when it’s back on line..

too frustrated to write more..
nite all, nite sam
-me