TAG | EUREKA
- What happened to cooling fall temps? Its hot again today! #
- And because Im saving the environment by not running the A/C, that means its 83 in my apartment. Uggh. #
- All 4 cores of my CPU have been at 100% load all night and temps havent gone over 60C. Compare this to when at idle I was running 64C… #
- I think my new cooler is working. #
- My Recent Tracks:♫Tantric – Hey Now
♫Autovein – Save Me
♫Adema – Do You Hear Me
♫See it @http://bit.ly/KW2sL # - New Twitterpic? I think it just might be #
- rt @terraamb when morons wash cars: http://bit.ly/gIi5m -> The brain power of these two is just astounding. #
- The timezone on my computer randomly changed to pacific time. Hello West Coast #
- Its hot and I am having a cuppa tea. I dunno, I just felt a strong desire for Earl Grey #
- My Recent Tracks:♫Tantric – Hey Now
♫Autovein – Save Me
♫Adema – Do You Hear Me
♫See it @http://bit.ly/KW2sL # - The soda machine is out of all but Diet Coke. #fml #
- RT @adamostrow: President Obama Calls Kanye West a “Jackass” – http:// bit.ly/Um2DK … for once, we're on the same page #
- My Recent Tracks:♫Manmade God – Safe Passage
♫Black Stone Cherry – Tired Of The Rain
♫See it @http://bit.ly/KW2sL # - RT @jeffswarensCompromise HC bill "only" costs 880 BILLION. Its still nearly a trilllion bucks. Not letting the govt run HC costs 0 #
- I'm not afraid to admit it. I backed up my Twitter account! You should backup yours here: http://backupmytweets.com/ #
- Calling Kanye West a jackass will never get old. http://imgur.com/h9Guq.png #
- These 8 hours shifts just keep getting longer and longer. #
- Use Coupon code "envelope" for 50% off all envelope orders http://spon.in/p2 1,000 for $59! #
- When asked what I have to say for myself, all I can say is "STEVE HOLT!" #
- Michael Hogan on this week's Warehouse 13. Its good to see him with both eyes after BSG #
- Eating some awful veggie beef soup from Campbells. This "Healthy Harvest" mess tastes like crap. #
- This eating healthier thing is killing me. Dammit I want pizza. #
- And to top it all off I'm drinking ice water. I would kill a man for a Dr. Pepper right now. #
- 80% of all pictures on the internet are of naked women #
- Uggh…awake before noon…this is bullshit #
- In regards to my previous tweet: I work nights, so it is normal for me to sleep past noon. My sleeping schedule is far removed from yours. #
- My Recent Tracks:♫Breaking Benjamin – Evil Angel
♫Three Days Grace – Gone Forever
♫See it @http://bit.ly/KW2sL # - Can you pass the US Naturalization test? http://bit.ly/Xy2m1 Take it a few times to get a better sampling of questions. I got 50/50. #
- Today is Constitution Day http://bit.ly/udXJF. 222 years ago today, the US Constitution was signed. #
- I wonder how the original 39 would react to the mess we're in today. #
- #backintheday 39 men signing a piece of paper changed the world. http://bit.ly/udXJF #
- !!AD!!: YouTube's hottest new show – http://is.gd/3ocXY is to online video what Siskel & Ebert were to the movies #
- My Recent Tracks:♫Lacuna Coil – Purify
♫Sirenia – The Other Side
♫See it @http://bit.ly/KW2sL # - Bills CB McKelvin’s front lawn vandalized – http://bit.ly/PIkxN – Come on Bills fans, we're classier then this. #
- Whats up with twitter images being messed up? Seems a lot of avatars are missing (mine included) and my background has changed. #
- My Recent Tracks:♫Dylan in the Movies – Give It Up
♫Tommy Lee – Tryin to be me
♫See it @http://bit.ly/KW2sL # - RT @Syfy: In honor of the Eureka finale tonight at 9pm, I'm giving away Eureka T-shirts to 3 random people who RT this note by 10pm PT #
- 5:35 on Friday and there is NOTHING going on. And to top it off I feel tired and achy. Fun day! #
- My Recent Tracks:♫Rage Against the Machine – Bombtrack
♫System of a Down – Sugar
♫See it @http://bit.ly/KW2sL # - RT @modmyi 500k MemberMadness Contest – Win a MacBook Pro/iPhone 3G[S]! Sponsored by FreshBooks.com/MiniBooks.app & NegriElectronics.com. #
I recently purchased a USB mug warmer off of ebay. It was one of the $2 ones, with integrated 4 port USB hub. It shipped in from Hong Kong.
At first, I found it fantastic. It seemed a great use of USB to me. I often consume warm beverages at my computer, but I usually don’t finish them before they get cold. Unfortunately, reality soon sunk in. The warmer just didn’t keep things warm. It barely got warm to the touch.
So, I dissasembled it. Taking a look at it, it was nothing more then a simple hub with an added resistor circuit on a switch. The resistors simply dissipated voltage when the switch was thrown.
So, the first “increase the heat” modification was to disable the USB hub that was robbing voltage from the heating element. I cut a trace on the board by scratching it with a screwdriver. No more hub voltage. But alas, even without the drain of the 4 port hub, it scarecly got any warmer.
I set aside the “heatsync” (a 1/8th inch thick piece of aluminum about the size of the bottom of a coffee mug) and let the resistors heat up on their own. After a 10 minute heatup…they got kinda warm. So, I deduced the resistors weren’t making good enough contact with the heatplate. I removed the globs of thermal paste, added a little back, and put a penny between each resistor and the plate. EUREKA…heat….but only in two very small spots. The resistors just didnt have the oomph to even begin to heat the plate up.
So, I decided to do some math. Ohms law to the rescue.
I = V / R
I being current in Amps, V being voltage in volts, and R being resistance in Ohms.
and
P = V x R
P being power in watts, V being voltage in volts, and I be resistance in Ohms.
After scraping off all of the thermal paste, I discovered that the resistors were 17 ohms. The two in series was 34 ohms of resistance. After some math, I found out that they were dissipating .73 watts of power. This is NOT a lot of heat. So, it was time for a drastic redesign.
I came up with this circuit.
All of the resistors in that circuit are 1 ohm, 1 watt resistors. The total resistance of that circuit is 10.5 ohms. Using the above formulas, that circuit would dissipate 476 mA of energy, less then the 500 mA possible from a USB port. It also would dissipate 2.38 watts of energy, producing a nice, toasty plate.
All of the parts have been ordered and are on the way. I’ll soon be posting photos of the build process and an instructable. I’ve already decided to use the housing from my current warmer, removing the built in circuit and adding to some mass to the warmer plate.
