Recent content by xw3850

For me to hold a heavy object stationary in air is tough and eventually I will get tired. So it seems I am expending energy. But then how much? I discovered it was quite hard (for me anyway) to calculate how much energy it costs to hold the object when there is no work. The only thing I could...

Oh ya, I supose that answer is only good for bipolar transistors. Not sure sure if there is a generic FET model. I kinda doubt it. The version I use is hspice. http://www.stanford.edu/class/ee133/spice/hspiceman.pdf There is a chapter that describe the various FET models in excruciating detail...

Are you interesting in how it models a transistor or how sets up and solves a system of equations? Pretty much any answer will be specific to a particular version of spice but for the transistor: In general this model is used...

Has the building itself done any recent upgrades? new power distribution throughout the floors, lighting, phone lines, whatever? One thing I don't understand. The radio would be an electrical signal going through the metal. I get how one could measure that, amplify it, and put it out on...

Doesn't radio station output, more or less, constant power? Shouldn't this mean the noise should be more or less constant? I would lean toward wind myself, but presumably there was wind when the building was initially constructed and I get the impression that the noise is a relatively new thing.

One more suggestion: Why cool a CPU? Using a fat power resistor or something would make this experiment much easier, and you could draw the same conclusion. Not quite as sexy though. :)

Oh, I don't want to discourage you from trying though. One can learn a lot from this type of experiment. Since this is a homework forum, I leave figuring out the proper way to measure the CPU die temp to you. It's actually a very interesting problem and different techniques have different...

Some things you may want to keep in mind: The internal temperature sensor in the CPU die (what the typical software app reads) is useless for this type of thing. It can easily have errors in the 10-15% range, and it's error can be non-linear. It's not really designed for performance...

actually, just to be 100% clear I guess I should have stated when phase = 0 then the load is purely resistive because the maximum current happens at the same time as the maximum voltage. Here pf = 1 and the leading and lagging term obviously do not appply.

Basically, The phase can vary between pi/2 and -pi/2. When phase >= 0, then the load is capacitive because the maximum current comes before the maximum voltage. This is leading. When phase < 0, then the load is inductive because the maximum voltage comes before the maximum current. This is...

Thanks Berkeman, I think I understand. So what parameters are most important in the Flywheel transistor? Obviously it must be able to handle the maximum amount of load current but I guess it should also have a saturation resistance low enough so that the Vds is small when it's conducting...

Hi, I am going through Franco's "Design with Operation Amplifiers and Analog Integrated Circuits" (an undergraduate textbook) and I am on the chapter about regulators and my question is specifically about the buck kind of switching regualtors. As I understand the basic operation of a...