6,785 reputation
1029
bio website embedinc.com/olin
location Littleton, Massachusetts
age 58
visits member for 1 year, 8 months
seen 4 hours ago

Electrical engineering consultant specializing in microcontrollers and the circuitry around them. Master of engineering in EE from Rensselaer Polytechnic Institute in 1980.

We are certified Microchip design partners, and have been in the top catagory consistantly since around 2000. Various free downloads related to developing PIC firmware and other things are available at http://www.embedinc.com/pic/dload.htm.


Oct
21
comment Why the bulb does not glow in this configuration of batteries?
Huh? There is way too much handwaving, and the description is poorly written and confusing. Show a diagram.
Oct
18
comment Spherical mirror ray diagram question
@TuP: What you are talking about is a approximation, useful only for spherical mirrors over small angles. A small piece of a sphere approximates a parabaloid well enough for some purposes, like a shaving mirror for example. For such small patches of a sphere, rays parallel to the axis get reflected so that they pass close to r/2. The bigger the angle of the spherical section, the more the error. To eliminate this error, the shape has to be parabaloid.
Oct
18
comment Spherical mirror ray diagram question
@TuP: Then you were taught badly. Or more likely, you misunderstood something.
Oct
17
comment Is a flow of ionized water an electric current?
@nonex: Ionic doesn't mean net charge. In fact, most things that are composed of charged ions have them in roughly equal opposite numbers. If they didn't, a net charge would build up, which would create a force that would migrate the imballanced ions back to equillibrium.
Oct
17
comment Objective visual reality
This is about philosophy, not physics.
Oct
17
comment Using a LabView interface, how do I control phase and intensity fluctuations in the RF electrical signal being fed to an AOM?
This is way too broad, and isn't about physics in any case.
Oct
17
comment What causes ballpoint pens to write intermittently?
@aitch: Yes, these pens do work better when warm. There is a marked difference between a pen that has been in a car in the cold of winter versus getting baked in the sun in summer. This appears to be because warmer ink is less viscous.
Oct
16
comment Can we double the electric energy?
@Abhis: As I said, it is quite possible to make a higher current out than in, so it's hard to tell what the point of your comment is. I even gave a example with 10 A in and 68 A out. If this is all you are after and both input and output are AC at the same frequency, then a transformer would be much simpler and can be made more efficient for the same cost.
Oct
15
comment Case of the mysterious bullets (taken from Mad About Physics)
Your quoted "question" is no question. Nothing is ever asked.
Oct
13
comment How would gravity change on a planet rotating around itself very fast?
Your last paragraph is incorrect. It makes no sense to talk about a "centrifugal force" without specifying a mass, which was never mentioned. You then compare that force to accelleration in the last sentence, which is wrong again. Either pick a example mass and use force consistantly, or probably better, stick to accelleration.
Oct
10
comment Storing a Planet-sized Chunk of Metal Inside a Star
@Luaan: Yeah, I was thinking of a fairly large orbit, something like several planets out, but at right angles to the predominant planetary orbital plane. As you say, someone would be quite unlikely to stumble upon it if they didn't already know it was there and where to look. In our system, I'd have it at a distance from the sun between the orbits of Mars and Jupiter.
Oct
10
comment Storing a Planet-sized Chunk of Metal Inside a Star
@Luaan: And why can't they store it by putting it in orbit around the star? That would seem both simpler, a lot more efficient, and within the realm of plausibility for the right kind of science fiction.
Oct
7
comment High power short duration from low energy source?
Whoever downvoted this, it would be useful to everyone to explain what exactly you think is wrong, misleading, or badly written. Silent downvotes do this site a disservice.
Oct
7
comment High power short duration from low energy source?
I don't need anything. I'm just pointing out that this doesn't really provide what the OP asked for. The problem is that you are totally ignoring the exponential nature of the voltage and current.
Oct
7
comment High power short duration from low energy source?
You are missing the point. The OP wanted 1 kJ in 1 ms, which your example doesn't provide. He didn't say anthing about a rectangular pulse, so a exponential decay is acceptable. The problem is your numbers don't work out. 1 kV on 1 mF into 1 Ohm isn't going to deliver 1 kJ in 1 ms.
Oct
7
comment High power short duration from low energy source?
It's not that simple. Your example starts delivering 1 MW initially, but will then fall off as the capacitors discharge. Due to the falloff, you're not going to get 1000 J in 1 ms.
Oct
6
comment Capacitors and Resistors - Series or Parallel?
Your question can't be answered because the initial conditions at the time the switch is closed are not stated. For example, if both caps are charged to 12 V initially, then nothing will ever happen in this circuit, forever (for ideal parts).
Sep
26
comment Existence of a physics-god
By bringing up god you already dragged this discussion into theology. This kind of nonsense simply doesn't belong here. -1 from me too.
Sep
25
comment What does it mean to have two phase coherent signals at different frequencies?
You can still talk about a phase relationship between two frequencies when they have a integer ratio, such as 3:2 in your example. In that case, you assume some reference, like the positive zero crossing, in each signal.
Sep
25
comment The earth is spinning, so why don't we jump and land on a different location?
@Holger: As the projectile falls back down, the discrepancy between its lateral speed and the ground's lateral speed decreases again, but the discrepancy still exists until the projectile hits the ground. The west offset distance is the time-integral of this lateral velocity discrepancy. The down portion of the flight contributes the same west offset as the up portion.