Recent content by superkaho

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    The superheating of distilled water in microwave oven

    As we know, the heating principle of microwave oven is by the vibration of water molecules inside the food. However, it is reminded that a cup of water should not be heated by the oven, otherwise, water would be overheating but not boils. Once it was stimulated, it boils. From the...
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    The cooling capacity of air-conditioner

    Thanks... By the law of conservation of energy, the equation: Qh = Qc + W decribes the heat released from condenser is equal to the sum of heat absorbed by evaporator and the work by compressor. However, when I investigate the COP = Qc/W. Though I accept COP can be greater than 1, but I still...
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    The cooling capacity of air-conditioner

    Thanks all your replies, here is to summarize the key points we've made. (1) COP is not the same as efficiency, but it can indicate how effective the air-conditioner to absorb heat by each unit of work input. (2) Air conditioner is not an energy converter, but just a device to transfer heat...
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    The cooling capacity of air-conditioner

    When the problem is considered for each part such as (1) compressor (2) cooling part. I understand the functions and the amount of energy transfer to be defined. For example, the work done by the compressor is W while the heat absorbed by the cooling part is Qc. I also understand that the work...
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    The cooling capacity of air-conditioner

    but the point is that the output(cooling capacity) is even more than the input(work done by the compressor), not the opposite. why? energy lost to the surroundings or by itself seems difficult to explain it...
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    The cooling capacity of air-conditioner

    I would like to ask why the cooling capacity of air-conditioner is 2-3 time more than the work done by the compressor?? According to the conservation of energy, the amount of work input should be equal to the amount of heat absorbed(cooling capacity), isn't it?? Can anyone explain it...
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    The measurement of current in electrical appliance

    As we all know, the current should be measured in series with the multimeter... However, how do we connect the multimeter in series with home appliance without damaging the wire(plug)??
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    Is Digi-Key the Best Source for Parts Information and Ordering?

    oh...this curve of the diode is really cool! but is there any other diode that can be interchanged?? because I just asked the store by phone and they said they do not have 1N5817. Instead, they only have 1N5819...Could you suggest some other diodes that can serve the same purpose?
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    Is Digi-Key the Best Source for Parts Information and Ordering?

    Thanks for your information, you are really great!:smile: Since I asked some salemans yesterday, but they just led me somewhere with plenty of electronic elements...such as resistors, diodes, transistor, IC etc... but what I learned the characteristics of diode is only about its unidirectional...
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    Is Digi-Key the Best Source for Parts Information and Ordering?

    Since the wind is artificially produced by eight fans outside a square, each side have two fans. (East, South, West, North). Each time only one side of the two fans are switched on. So in order to capture the maximum amount of wind energy, I can only place them face to each fan with the least...
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    Is Digi-Key the Best Source for Parts Information and Ordering?

    Thanks for your reminder~~ Suppose each generator can prodcue the emf with 2V. Which circuit design below would be better for maximizing the power output of 50 ohms?? Each two generators are placed in four different directions. (i.e. East, South, West, North) Only one side of...
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    Is Digi-Key the Best Source for Parts Information and Ordering?

    For those 8 mini-turbines, only 2 or 4 of them are operated at the same time. Would the other turbines become motors and dissipate power from the 50 ohms resistor? It is known that the internal resistance of each generator is around 14ohms. How should I connect them such that the maximum...
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    Is there an Optimal RPM for a DC generator?

    yes, I must use the given generator to produce the maximum power output across a 50ohm resistor...Suppose the wind speed is 3.5m/s from a fan. What I can vary is the gear ratio, blade shape/material/size (swapped area).
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    Is Digi-Key the Best Source for Parts Information and Ordering?

    Suppose there are eight mini turbines each genearate voltage with 1.5V, if I want to measure the total power produced by them. Should I connect them in parallel or in series circuit with the 50ohm load? Which method is more accurate? If they are in parallel, the voltage across the load...
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