Recent content by Nanren888

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    Strange homemade device found hidden.

    Not really the clearest of images. Where do/did the wires go. Looks like power, like a light or similar rather than anything as complicated as radio. Any more images? from different angles?
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    Simple lamps circuit

    What's your starting point? The switching seems ok. What do you know of switches? There is a time element involved, as one seems to flash. What do you have that might be able to change with time after being turned on?
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    How to translate compartmentalized liver to analog computer? I Just want to learn to translate the f

    Maybe someone else with the same homework. Should they have asked you? Did they state the question more clearly?
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    Bluetooth controller - does one exist?

    What experience does he have? There are lots of boards that are programmable & have BLE. Many will take add-on boards that will control higher voltages. They tend to need some programming and wiring. . I googled "bluetooth relay board" and got a few hits on board that show a phone controlling...
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    How to translate compartmentalized liver to analog computer? I Just want to learn to translate the f

    Seems to match. Did I miss something? dx_2/dt = term in x_1 + term in x_2 + another term in x_2 Why two terms in x_2 ? - I guess they must represent competing processes or something dx_2/dt = k12 * x_1 + -k21 * x_2 + k23 * x_2 Seems to match.the equation to the figure. What is the question...
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    Detection of electronic device

    Have you got a reference or link to "the handheld one"?
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    LED Array question

    Summary: parallel LEDs without individual resistors are often not a good idea as one gets most of the current, blows up, then the next one gets most of the current and blows up , until there are none left. . If each LED can take the max current, then no blow, up, but they will have dfiffernet...
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    Microcontroller USB clarification

    The devices I have used that do this, such as my phone or a pi, have a single connector and you use a cable to adapt when you want OTG. This, way it is one at a time. . Not that many devices use "B" anymore.
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    LED Array question

    yes, but, ... not so clearly ok. I don't know how flickering LEDs work. LEDs will not actually have the same voltage drop. Also the voltage tends to go down with temperature, so if one gets more current, hence gets warmer, its junction voltage will drop and will get more of the current...
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    electronic following circuit

    So, if you are still interested to learn, there are some ideas above. In terms of technolopgies that you might like to look at; UWB ultra wide band - on recent phones. Recent phones are actually a good platform for proof of concept trials as equiped with multiple sensors A111 and similar radar...
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    electronic following circuit

    step one: google it with the aim in mind rather than the technology to do it. If you don't find anything, there could be good reasons for this. Often it's just not a good idea, or some parts of the technolgy are beyond reach, either complexity or cost/practicality. Sometimes also safety...
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    Electric circuit problem

    Not sure what you mean. It has 0.7 mA of base current. So it is driven at least. For any real transisitor you can look up characteristics to check the effect of this with a 5k load, from a load line on the characteristic curves. . Or <Proof by spice> That LTSpice says Vce is 0 means it is on.
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    I need to boost the signal on a fm modulator

    Many places have provision for low power FM stations. Some places have compulsory inspection of equipment before starting, others don't. These licenes will often get you a Watt, but take some arranging. In areas where this is possible, there are often pre-approved hardware options. Often only...
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    How do I measure a material's capacity for ultrasonic media use?

    Do you mean as a projector or receiver of ultrasonic waves, such as piezo-electric properties, or as a medium that the wave pass through? As suggested in the matrial referenced above, coupling into & out of the medium is often relevant; if there is a significant impedance change at the...
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    Help needed

    Like 5 volts to 50volts? power? Or a 5microVolt signal that you want to see at 1 volt? AC or DC? What are the constraints?
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