Hi, I’ve just been reading about the mutual inductance coupling that can exist between adjacent conductors in a 3-phase power distribution system. I’m hoping to clear something up in my mind, if we want to model the imposed mutual impedance, is it represented as impedance between the lines...
Hmmm. I would think generally that the speed of the rotor is not only determined by the rotating magnetic field but also by the load. Assuming no losses if there is no load then there rotor will turn at sync speed and therefore no current will be induced.
But anyway, I guess I need to make my...
Yes, I understand that there needs to be slip and the speed of the rotor will depend upon the load I guess. But what I don't understand is the speed of the magnetic field set up by the rotor due to the induced voltage? Will it slow down as the rotor spins slower?
This is probably a simple question with a simple explanation... I understand that a 3 phase induction machine generates a rotating magnetic field in the stator which by Lenz’s law induces an electromagnetic force in the rotor which moves the rotor in the same direction as the stator magnetic...
The datasheet says +-18V. Hmm, in the past I've never had an issue with powering the same IC with +-15V. I don't see why +-12V would affect operation?
The circuit is very simple, i'll upload an image for you to see for yourself.
Thanks :)
Hi Guys,
I'm trying to amplify a millivolt signal from an electrode that has a high input resistance (~ 200 MOhm). To avoid losses over the series resistance I'm using a high input impedance Op Amp TL071CP as a voltage follower. The problem I'm having though is that for some reason when the...
I just want to clear up my understanding of rated power systems.
For example, if an electrical system is rated 5kVA at a nominated supply voltage and power factor does that imply that the total apparent power (S) supplied to the circuit must equal 5kVA?
Thanks.
I understand that part. It's the actual integral that I need to evaluate that I'm not sure about.
-\int_{0}^{\pi / 2} e^{-st} \sin 3t dt Can i just do that or must the integration limits be between zero and inifinity to transform the function?
Yes, it is but it's the next step that confuses me.
Laplace transform is defined as
\int_{0}^{\infty} e^{-st} f(t) dt
Since we have a different limit how do we transform the function \mathcal{L}\left(-\sin 3t\right) for t\in\left[0,\frac{\pi}{2}\left) ? I've only been learning...
The question that I'm asking is:
\mathcal{L}\left\{ \sin (3t) [ h(t - \pi/2) - h(t) ] \right\}
Heaviside function definition is:
h(t - a)=\left\{\begin{array}{cc}0,&\mbox{ if }
t< a\\1, & \mbox{ if } t\geq a\end{array}\right.
I hope this makes it clearer to understand...
Yes, the h is the heaviside function. The correct answer to the problem is -1/(s^2 + 9) * (3 + se^( (pi * s) / 2 ). I can get -3/(s^2 + 9) but not sure how they get (3 + se^( (pi * s) / 2 ) for the next term.
Do you know where I can get a list of LaTex commands?
Hi. I'm trying to find the Laplace transform of:
sin[3t] ( h[t - pi/2] - h[t] )
I realize that this function is only valid for 0 <= t <= pi/2.
Since the limit is not from zero to infinity (0 to pi/2 instead) how can I use the laplace tranform definition to solve this?
Also, does...
Thanks for your detailed response learningphysics. It's helped clear some things up.
Just another question related to current flow and probably a stupid one but can two currents produced by two indepandant batteries in a DC network flow in opposite directions through the same branch? I have...
Hi Guys,
I'm a first year Electrical Engineering student and we're just covering the basics of circuit analysis. Currently we are going over Nodal analysis.
I'm having some trouble correctly identifying the currents that are entering and leaving a node in a circuit. I can get most simple...