Recent content by lucy_b14

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    An amplifier that won't amplify

    Hi I've built what is meant to be a non-inverting dc amplifier using a 741 op-amp (shown in attached diagram). Resistor values are: R0A= 470k, R0B= 47k. I am feeding the op-amp a supply voltage of 12v and an input voltage to the non-inverting input of 0.5v. According to the resistor values...
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    Re-writing aircraft equations of motion (attachment problem fixed)

    Hi, I hope someone can help me with this question, I originally posted this question in the homework help forumbut no one seems to be able to help me with it. I think my problem is more math related - I don't really know where to start. I have been a given a matrix containing aircraft...
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    Full wave rectifier for piezoelectric stack

    I'm afraid I can't work out what you're getting at. Having tested the piezo stack using an oscilloscope, it clearly shows an AC signal when an impact is applied. As far as I can tell, the only way to extract maximum available power is to rectify the output. Please let me know if I'm getting...
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    Full wave rectifier for piezoelectric stack

    Hi My project involves rectification of a voltage produced by a piezoelectric stack subjected to an impact. The voltage shall be rectified using a full wave bridge rectifier. I aim to use a capacitor (in position of the smoothing capacitor) to store the energy harvested from the impact...
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    Where can I find a piezo stack for a reasonable price?

    Hi I'm planning an experiment in which I will try to generate power from a force applied to some piezo electric material (in fact it will be an impact with the ground). I think I need to find a piezo stack, but where can I buy such a thing for a reasonable price? Does anyone have any...
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    Generating using a DC brushed motor

    Good Evening I'm interested in the possibility of using a DC brushed motor as a generator (ie running it in reverse - mechanically turning the shaft to produce electricity). However, I have no idea how to calculate the power I could potentially achieve. Any tips or equations in particular...
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    How Can I Calculate Power Requirements from a Sensor Datasheet?

    Hi Sorry, I guess I was a little sparse on detail - I was trying to keep it simple! I am basically designing a wireless autonomous sensor device powered by energy harvested from the surrounding environment. This energy will need to be stored in a battery, so I need to find the amount of...
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    How Can I Calculate Power Requirements from a Sensor Datasheet?

    Hi I am trying to calculate the power required to take a measurement using a sensor. Datasheets do not provide the power requirement for devices (in watts). Can anyone give me any advice on how to find the power requirement using information provided in a typical datasheet? I know I could...
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    Strut Braced Wings: Advantages, Disadvantages & Commercial Use

    Hi Does anyone know the main advantages and disadvantages of strut braced wings on fixed wing aircraft, and why they are not used for any large commercial planes these days (as far as i know!)? Thank you
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    Finding the Phase Angle & Understanding Bandstop Filters

    Hi Does anyone know the equation for the phase angle by which v0 leads v1 in a bandstop (parallel resonant) circuit? also, can anyone tell me how (in terms of the equation for the transfer function) a bandstop filter works? Thanks a lot, any help appreciated. :redface:
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    How do actuators in fly-by-wire systems on aircraft work?

    Hi, I'm doing some research into fly-by-wire system on aircraft and need some more information on actuators. I know that electrical signals are sent to the actuator from an onboard computer, but I'm not sure how the actuators then move the control surfaces. Do they use hydraulics? If so how do...
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    Scientific reasons why airfoils are used to straighten airflow

    thanks a lot! it does make sense
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    Scientific reasons why airfoils are used to straighten airflow

    yeh, its to do with my last post, but the replies don't seem to explain why an airfoil straightens airflow.
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    Scientific reasons why airfoils are used to straighten airflow

    can anyone tell me the scientific reasons why airfoils are used to straighten airflow (e.g. turbulent flow from a fan or propeller). i know how they are used to produce lift, but cannot see how they straighten airflow. thanx! o:)
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    Investigating Air Flow from a Fan: Vortex, Equations & Airfoils

    I am doing an investigation into the air flow from a fan in my physics class. I need to know why the reason why air flows in a vortex shape from the fan (in physics terms), and what equations I can investigate (anything, e.g thrust etc). Also, I believe the airflow from a fan can be...
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