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1
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3answers
496 views

Intensity distribution of a LED light source

The light source: 190 high power LEDs in NIR. I have the datasheet of the LED. I want to make a graph showing the spatial distribution, and to measure the intensity of the beam on the whole field of ...
1
vote
0answers
114 views

Simplifying a biquadratic filter equation [closed]

I am trying to calculate input impedance of a multiple feedback low pass filter. What I need is the symbolic expression as simple as possible so that later I fill in the values and get the impedance ...
2
votes
1answer
521 views

Electrical flow in a simple parallel circuit

I'm having trouble understanding something in one of my text books: Let’s have a look at the implications of each circuit configuration. Figure 3.13 shows the Conventional representation of a ...
3
votes
2answers
503 views

The role of resistor in e.g. an AND gate

What is the role of the resistor in e.g. an AND gate like this one? : One often sees lots of resistors in electric circuits, but I haven't really understood their role.
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votes
3answers
5k views

Calculating time for a fully charged UPS

I have a UPS of 1000 Volts connected with 2 batteries each of 150 Amp. How much time it will take to consume the whole UPS (after fully charged) when a device of 1Amp is getting electricity form that ...
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votes
3answers
5k views

Why and how exactly is electric motor torque limited?

Inspired by this question and specifically this answer to it. From my experience there's always some very specific limit to how much torque an electric motor can output. For example, an electric ...
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votes
6answers
9k views

What would be the effective resistance of the ladder of resistors having n steps

I'm a tutor. This is a high school level problem. In high school, every one have might have solved a problem of effective resistance of a ladder of resistors having infinite steps. Now the problem is ...
0
votes
1answer
214 views

Waveforms for a given ideal inverters circuit

I have the following circuit. All the inverters are ideal CMOS. I need to draw the waveforms for each point (A, B, D, E, Vo), given that waveform at input. What I want to ask is if what I did so ...
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2answers
386 views

A lightning protection device physics

Here is a description of the principle of the operation of a new lightning device: During a storm the ambient electric field may rise to between 10 to 20 kV/m. As soon as the field exceeds a thresold ...
6
votes
2answers
1k views

Lots of little questions about radiation of LC circuits

I'm trying to get a more intuitive understanding of resonant inductive coupling. It's supposed be a more efficient way to transfer electrical energy wirelessly, because the coils are only coupled by ...
8
votes
2answers
550 views

Torque of an electric engine

So I have some follow up questions from this thread: Electric engine transmission Basically, I am looking for a more precise mathematical statement that makes this true. Why is it that the electric ...
13
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7answers
3k views

What is a general definition of impedance?

Impedance is a concept that shows up in any area of physics concerning waves. In transmission lines, impedance is the ratio of voltage to current. In optics, index of refraction plays a role similar ...