# Tag Info

2

(Remote Control) RC servos usually have that type of functionality and they --usually-- use a PWM pulse to control the position. The standard idea is (used to be) that you provide a digital pulse (either Hi or Low) 50 times per second (so the duration of the pulse is 20[ms]). Modern RC servos can be more forgiving and can have different times. The duration ...

0

The brake works by converting motion to current, and current to heat. The current in this case will be vertical, as it is perpendicular to both the motion (forward) and the magnetic field (horizontal). If the magnets are all facing the same way, they will maintain a DC voltage from the top to the bottom of the rail. This is interesting, but doesn't ...

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Not 100% sure what might be the problem in this case, but there are several reasons what could go wrong. I personally had a tough time not logging the right CAN data, so you should make sure you are doing it correctly. Then it can be the actual domain frequency... There might be a problem in hardware or software you are using or the actual connection between ...

3

Each pair will act like a horseshoe magnet with the rail acting as a "keeper" which closes the magnetic circuit and will result in maximum friction. The alternative is to place all the same poles touching the rail with the result that the flux path to the other pole must travel through the air. The permeability of air is about 0.001 times that of ...

0

Weight. As turbines get larger, it's the point of diminishing returns it takes a steady and constant wind velocity in order to accomplish the same goal. The bigger the machines get...........the efficiency rate declines. It's all based on the Cube square law. When an object undergoes a proportional increase in size, its new surface area is proportional to ...

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Just use 2 separate supplies (with appropriate current ratings). Or a 12V supply and a buck regulator. There are power supplies with 2 outputs, but they are generally designed for a specific purpose, eg. PC power supplies which can provide 12V and 5V. I am not aware of any common dual supply that provides 12V and 6V.

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Your cell phone contains an oscillator. This is a circuit which when fed direct current converts it into ultrahigh frequency sine waves, which are then modulated by an encoded version of the audio signal from the phone's mic unit.

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For any battery which works via electrochemical reactions, the voltage output of the battery will be the same regardless of its size as long as the chemistry is the same. However, the current output of the battery depends on the square area of the surfaces upon which the chemistry is taking place. Small surfaces, as in small batteries, means small amounts of ...

2

There is an upper limit for how loud a sound that can be produced in air on earth. I think that moonshot rockets were about as loud as a sound can be. Now we have sound propagation. This will be affected by the ground, temperature, conditions, and a ton of other things. Realistically, to get sound traveling "the maximum" we will need conditions ...

2

The nyquist plot is nothing more than just a polar representation of the bode plot (assuming we neglect negative frequencies). So if you know how $e^{-Ts}$ affects the bode plot, you can essentially just pick a certain amount of frequencies, get their phase and magnitudes from the bode plot, and compute its corresponding position in the Nyquist plot. Just ...

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As you note yourself, Kv = 1/Kt. 200 Kv (RPM per volt) = ~21 rad/sec per volt. Invert this to get a torque constant of 0.04775 Nm per amp. This is what you want to know. As you calculated, at peak power, the motor will draw 41.7 amps. Multiply this by the torque constant to get about 2 Nm of torque. The issue I see is that you are assuming that all of the ...

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There are three ways I can think of to do this off the top of my head. The first would be to spring load the poster in the retracted position. When the motor loses power, the poster retracts on its own. When the Arduino is powered, it can drive the motor to open the poster and hold it there. Mechanically this is more complex. It requires well balanced forces,...

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Instrumentation engineer, with emphasis on optics, controllers, and the other stuff you said. What you described is a great rap sheet for looking for a new job! And definitely emphasize NASA. I would not say "systems engineer" since in my experience in aerospace that implies someone who works on writing and tracking requirements all day, and you ...

1

Kv is for back EMF. It is part of what you need to model the current, in addition to the resistive and inductive model of the motor windings. The current then gives your torque via Kt. This is all to a first approximation. Here's a paper that describes the model, in Section II.C, equations (1-3) https://www.researchgate.net/publication/...

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Your definition of $K_t$ seems a mistake. By definition, the torque constant is simply the slope of $T (Nm)/i(amp)$ curve of a motor, and It should be noted that the parameter $K_t$ is not related to the voltage under which the motor is operated. If you use the motor at 12VDC or 24VDC this constant will remain the same. This attribute of the motor is very ...

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