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  1. L

    Piecewise linear diode model?

    A search for "piecewise linear model" turned up the following link: http://www.ittc.ku.edu/~jstiles/312/handouts/The%20Piecewise%20Linear%20Model.pdf How many regions of the V-I curve are you expected to model?
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    diodes conducting in different cases?

    The general technique is to replace the diode with either a short circuit or an open circuit then look for a logical inconsistency. Does the short circuit current flow in the forward direction? Does the open circuit voltage reverse bias the diode? If one of these conditions is false, then...
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    Help with Resistor question, for a non electronic's guy

    Soft plastic or rubber material may not be a very good conductor of heat so the temperature differential may need to be relatively high. I would recommend a concept feasibility test. Take an empty container and mount a 500 watt infrared reflector bulb in the center pointing upward. Then pile...
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    pulse count

    This is the sort of project that begs for implementation with a microcontroller. The basic program would count impellor pulses in a register, reset the register when it reaches 720 and also increment the display register. It is a one-chip solution versus doing the same function in hardware. A...
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    Help finding voltage across diode

    The saturation current is a parameter of the diode itself, and is the "Io" value in the ideal diode law.
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    Help finding voltage across diode

    There are some conditions left unsaid by the problem so I would just assume ideal conditions. Use the ideal diode law at room temperature, 300 Kelvin ( http://pvcdrom.pveducation.org/SEMICON/EQUAN.HTM ). Then for any given diode voltage you can calculate the corresponding diode current. To...
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    Help with noise issues

    Your circuit may be susceptible to spontaneous oscillation due to the high degree of cross coupling in your wiring method. For non-clocked gated circuits this type wiring might not ordinarily be a problem, but with no power decoupling capacitors and no semblance of a ground plane that I can...
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    NE555N vs NE555P

    In general the beginning letters refer to the temperature range that the chip has been designed for, while the ending letters refer to the package the chip comes in. Some manufacturers use 'N' and others use 'P' to refer to the PDIP package or Plastic Dual In-line Package. So it is likely that...
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    problem with op amp positive and negative feed back at a time?

    Just write the node equations at the op-amp inputs, then solve for the output voltage as a function of the input voltage. See attachment.
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    Meaning of BATERRY polarity

    @lefam: "So in a battery, ....." It is not useful to think about what happens in a battery because then you have to think about electrons and how electrons behave in terms of chemistry. That is a chemistry issue, not an electronics issue. Focus your attention not on the battery but on the...
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    problem with op amp positive and negative feed back at a time?

    The basic technique for analyzing an op-amp circuit is to calculate the voltage at the (-) input to the op-amp as a function of the output and/or input voltage. Then do the same for the (+) input. Set these two expressions equal to each other, V(-)=V(+), then crank the algebra to get the...
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    Meaning of BATERRY polarity

    Don't get too concerned about the flow of electrons. For all practical circuit analysis and design purposes, just assume that current flows from plus to minus. About the only time you will need to consider electrons is in the study of quantum electronics and the physics of the P-N junction...
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    Pre-amplifier and Amplifier difference?

    Would you place the most attention to low-noise electronic design in the pre-amp or the power-amp? Why? Would the volume control, equalization, and tone controls be placed at the input to the pre-amp or at the input to the power-amp? What is the voltage gain and current gain of each...
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    diodes conducting in different cases?

    The problem states that the diodes are ideal. That must mean that the diodes have no forward voltage drop and no reverse current. So in one circuit D1 will have no voltage across it and in the other D1 will have no current flowing through it.
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    Intrinsic carrier concentration

    I input your equation to mathcad14 then asked it to solve for T and got an answer as shown in the attachment. I'm not really sure what that all means except that it must be difficult to find T as a function of N.
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    Deadmau5 helmet (a "helmet" full of LEDs)

    I'm not so sure that the mouse head is constructed from an LED matrix. It looks more like the result of video rotoscoping with color screening, and masking or keyframe tracking. The mouse head may just be a mask where another video signal is substituted for the mask. See your local weather...
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    Factors that can cause charge/discharge rates of capacitor to be different

    Electrolytic capacitors are based on a chemical reaction which may not have exactly the same rate in the forward and reverse directions. Also, electrolytics have noticeable internal leakage. Film and ceramic capacitors exhibit dielectric absorbtion or soakage which is fairly linear for both...
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    Stuck on this one.

    Whenever you are stuck, draw the Karnaugh maps. That way you don't have to think about it. Just follow the rules for minimization, and believe what the K-map tells you.
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    Questions n, n+1, and n+2 from my homework

    Could your fan motor be one of those single-phase capacitor-start induction motors? Or one of those permanent-split capacitor (PSC) motors without a centrifugal switch, such as are often used in air movers and ceiling fans? My 220 volt pool pump motor seems to be a PSC motor.
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    Biasing (question 7 of my homework)

    The dictionary can be your friend here. My Websters New World College Dictionary defines bias as: "<Radio> the fixed voltage applied to an electrode circuit to control the mode of operation, usually measured with the cathode voltage as reference." So 'biasing' means to apply a bias to an...
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