FreeDave

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Chief Technologist

Dave Freeman is a Texas Instruments Fellow and Chief Technologist for Power Supply Solutions in the Power Management business unit. Dave has expertise in the areas of battery management ranging from charging to capacity estimation. In the areas of power management, he covers low power DC/DC, high frequency power conversion and digitally controlled power. Other areas of focus for Dave are renewable energy systems and low power energy harvesting. Addition interest includes sensors and analytical methods used to evaluate physical properties of materials. Dave offices inside Kilby Labs where he manages the energy lab as well as power/energy related research projects.


FreeDave

's contributions
  • 06.02.2014
  • 1 Comment(s)
Bring on the drones
  • 02.03.2014
  • 2 Comment(s)
Set-top box and saving energy
  • 07.31.2013
  • 2 Comment(s)
Helping batteries last longer
  • 06.18.2013
  • 5 Comment(s)
The value of efficiency
  • 05.07.2013
  • 2 Comment(s)
Big numbers, big confusion
  • 04.30.2013
  • 2 Comment(s)
What does “access” really mean?
  • 07.31.2013
  • Helping batteries last longer
  • Hello John, Battery capacity fade is a popular topic in various smartphone forums for example the Android forums. Even USA Today had an article about this topic, http://www.usatoday.com/story/tech/2013/08/16/macbook-air-battery/2665109/ You can find additional information by searching in Google and entering "Battery Fade Kinetics".
  • 06.18.2013
  • The value of efficiency
  • Here is a link to energy use by washer. downloads.energystar.gov/bi/qplist/res_clothes_washers.pdf‎ Many washers use only 95kWh per year based on 392 loads and including the water heating but does not include drying energy. At $0.10 per kWh, that is about $9.50 per year. So in what planet and what universe, it seems Earth and our Universe which can be narrowed down to the Milky Way galaxy. The numbers that my friends were using probably came from the Energy Star label where the water is heated by gas so the cost is only for the electricity used by the washer.
  • 06.18.2013
  • The value of efficiency
  • I did not know that. I just thought they committed suicide and became drier lent. Do you know if they become plastic, wire, or wooden hangers?
  • 04.30.2013
  • What does “access” really mean?
  • It does seem that the hardware has the knobs but they are not used to minimize the energy. I guess the issue is that hardware and software do not speak the same engineering dialect. I think there is hope in that many universities are putting courses together.
  • 02.20.2013
  • Runaway Lithium-Ion batteries
  • Thanks for all your comments. Airbus has announced that they are changing out their Li ion batteries on the A350. I do not recall any reported issues for them. Thanks LostInSpace2010, yes I recall an event where a power tool NiCad pack was being charged by a lab supply. Things may have been fine except the person in "charge" went to lunch. The battery did get hot enough to vent the aqueous mixture of potassium hydroxide. No real damage other than everything on the bench was coated. Thanks pete22, if there were a good way to detect a potential problem they may have been able to shut down the back before it had the potential to run away. If they could tolerate the extra redundant cells, they could have used the lithium iron phosphate cell. I appreciate the comments and look forward to more discussion.
  • 12.04.2012
  • How do we get to a DC-powered home?
  • First, I would like to thank you for all the comments and insights on this topic. DC does have its issues with arcing and this would add to the cost of implementation. Adding a detection circuit for low voltage arc detection would be a challenge especially when cost is considered. This may end up restricting DC to applications that are not hot pluggable. Otherwise, a circuit would need to be added that detects the absence of a load and reduces the current to some sleep-non-arcing level. The circuit would have to detect that when a load is connected before powering the socket. Again this may have cost issues that make it not acceptable. As suggested, LED Lighting would seem to be a natural fit for a distributed DC bus. This could service all the fixed light fixtures. A good point is made about general distribution and the likelihood of having adapters at the end just due to the diversity of DC voltage requirements. One benefit would be having just one PFC circuit that could service all the low voltage low power DC loads. For heating and cooling, two charts do make sense and would make it easier to interpret. However, I think the government was trying to convey the annual percentages. I am impressed by the number of you that have centralized DC implemented in your homes. It is through your experiences we can judge the level of practicality for DC distribution home systems. Energy storage is a good portion of the reasoning behind a DC system. I would certainly implement large energy storage in my house when the cost hits about $100/kWH. I think we are a long way from a DC only home in the US. In the end, it will mostly be like some of you suggest, a hybrid system of AC and DC in the home with AC feeding the house.