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  1. L

    Why is this so?

    You might want to look up information on the Crookes Radiometer to determine if there is any bearing on your question. Also, consider the following extract on the pressure of light: http://www.dartmouth.edu/~pressureoflight/history/history2.html During the period 1900-1903, Ernest Fox Nichols...
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    OP-AMP negative feedback intuitively

    I don't really understand this technique of iterating through the feedback loop. Never heard of it. Ideal op-amps have instantaneous response so iteration is not necessary. But real op-amps are not ideal. The linear operating region of a real op-amp exists only when the input terminals are...
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    Why is this so?

    Simple physics. Consider the equation for motion -- Force = Mass x Acceleration; and the equation for the weight of an object -- Weight = Mass x Gravity. When an object is falling, and ignoring air resistance, the only force acting on the object is its weight. So substitute weight for the...
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    Definitions for op amps?

    Recall from Algebra I that a straight line is defined by a slope and zero intercept. Your circuit, regardless of the resistor values, has a zero intercept of zero, i.e., zero at the input produces zero at the output. So instead of one of the circuit inputs being grounded, it would need to be...
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    Definitions for op amps?

    Attached image extracted from Texas Instruments Application Report SLAA068A - April 2000 "Understanding Basic Analog – Ideal Op Amps" It explains how to analyze the op-amp differential amplifier circuit shown in your image.
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    Which Switching Transistor?

    The LM35 is a Centigrade temperature sensor with a scale of 10 mV per degree. So an output of 300 mV equates to a temperature reading of 30 deg C, while 301 mV is 30.1 deg C. So if you want full-current turn-on within 0.1 deg C, then use a voltage comparator and a band-gap voltage reference to...
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    Kirchoffs First and Second Law in this basic circuit:

    First, realize that you are not going to 'verify' Kirchoff's law by finding the answer. Rather you will be using Kirchoff's law in order to find the answer. For instance, when you assume the presence of a loop current, the voltage drops are expressed as IR drops - the product of the loop...
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    Kirchhoff's Law

    So I took your two equations and plugged them into a computer algebra system for a solution. Have attached a cropped screenshot of the whole thing. Note that other than typing your equations and component values once into the equation editor, all the rest was copy/paste and menu selections...
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    ELECTROMAGNETS

    If you don't supply electricity to the fan, then where will the energy come from to turn the fan blades?
  10. L

    Kirchhoff's Law

    It is a four-step process: 1. Decide what analysis method to use. 2. Follow the rules for converting the circuit diagram into a set of algebraic equations. 3. Crank out the solution by solving the set of algebraic equations. 4. Use the solution to answer the other questions. So have you...
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    7 segment decoder

    HD74LS248
  12. L

    Is this possible?

    What you have is an idea and a concept. What separates a concept from a working system is engineering, politics, and funding. The engineering is the interesting part; not so much for the other parts (at least for engineers).
  13. L

    flyback voltage

    When the loop is closed current (blue) from the battery flows through the resistors and inductor. Note that the diode is reverse-biased. When the switch suddenly opens, current through the inductor does not suddenly stop, rather the inductor generates a flyback voltage as high as necessary to...
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    Transistor Switch HELP!!

    To provide more clarity I would advise replacing the voltage divider with its Thevenin equivalent. Then get an upper bound on the collector current in the ON state; assume Q1 is in saturation with Vce = 0.2 V. Then Ic = E/R = (1.226 - 0.2)/(8171 + 36K) = 23.2 uA with emitter voltage Ve = 0.84...
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    Transistor Switch HELP!!

    Changing R11 has no affect on the OFF state voltage.
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    Transistor Switch HELP!!

    The highest U13A input voltage occurs when the transistor is non-conducting (OFF) and the R1/R3 voltage divider gives 1.22 V. When Q1 is conducting (ON) the collector pulls current from R3, lowering the input voltage generated across R3. So if you want a lower input voltage, drive Q1 into...
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    Sine Wave using DAC?

    The question might as well be, How can an arbitrary waveform be generated using a DAC? So I Googled for: DAC signal generator arbitrary waveform. The answer is out there.
  18. L

    flyback voltage

    I used LibreOffice Draw to create the schematic, and used GIMP to finalize the graphics .png file, both running on Linux. I think there may be versions that run on Windows (don't really know and don't care). Have attached a copy of the Draw .odg file with your schematic on the second slide...
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    RS Flip Flop with Clock Pulse

    When you add clocked flip-flops to a logic circuit, it changes from simple gate logic to a synchronous state machine. The state at any time 't' is given by the value of all the flip-flop outputs, Q(t). The clock is implied by the 't+1' where Q(t+1) shows the new state after the clock pulse...
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    flyback voltage

    I believe this is the schematic translation of the ASCII diagram: Can you see why this won't work? :(
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