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    Radio Circuit Analysis

    How would I go about analyzing a circuit such as the one below? I have a few questions to start with: 1) Do you consider the antenna an AC voltage source? 2) What is the purpose of C2? I'm assuming it's to reduce noise, but how exactly does it accomplish this? 3) If I wanted to use an NPN...
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    Oscillator output

    Just a quick question or two.... does the sine wave output of a hartley oscillator (or colpitts or another sinusoidal output oscillator) create AC (does the output voltage go negative)? Or is it just DC with voltage moving smoothly up and down? Also, if I were to take a 1MHz signal from a...
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    Help with radio circuits

    Hey again guys, in need of a bit of help again. In my robotics class at school (which basically turned out to be a electronics/ infrastructure physics class) we have a summative project due at the beginning of june, and I've got a great idea for the project (mine is a new security feature for a...
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    Inductance of a coil

    I need to build a coil with these specs: 1 inch length, .5 inch diameter, ferrite core, 30 turns of 22awg wire and 3 layers. Can anyone give me a pretty accurate measure of the inductance of that coil? This is for a capacitor charging circuit, and I've done a few calculations of my own but I...
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    Transformers

    Just a quick question: Lets say I have two transformers, one with a 2:1 voltage ratio and one with a 3:1 voltage ratio. If I were to hook these up so that the voltage gets increased twice, would the output voltage be 6 times as much as the input? Would the current follow the same pattern as...
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    High Voltage Cap charger

    Hey guys, just doing some research into converting voltages, and I was just thinking: Would it be possible to say hook up a 9v battery to a IC555 timer, and connect the output of that timer to the primary winding of a transformer and connect the secondary winding to a high voltage capacitor...
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    Simple transistor question (probably)

    Hey again everyone, just one simple question about transistors: Why do people say something like 'a transistor typically has .6V from its gate to its emitter and .2V from its collector to its emitter'?? Doesn't the voltage get determined by the rest of the circuit? Like for instance, if I put...
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    Op Amps gain

    Ok, if the data sheet for a differential op amp says 100dB, then that means a power gain of 10 000 000 000 right? Holy SMOKES! That can't be right. The way I figure that huge number is 100dB = 10B right? And the way to get the ratio gain from B is to put 10 to the power of the bels, so 10 to the...
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    Inductance

    I have a question about inductors. Inductance is the same thing as Field Intensity right? They are both measured in Henries. So then why does one formula for figuring out the field intensity rely on the current put through the coil and one doesn't?? Heres one formula : L = ((Number of Turns)
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    Laser Parking Aid Schematic

    Lately my parents have been having a hard time parking their car in the garage because of visual obstructions. I have a circuit here that will use a 5v power supply (probably plugged into the wall, batteries wouldn't last long enough) --d1 is a laser pointer --r1 dissipates .5V so that d1 runs...
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    Ok, only one more question about transistors, I promise!!

    Ok, now that I've got the hang of what they're for, and things like DC gain and such, how would you design a circuit and figure out the specs for your transistor? For instance take this circuit for example: How would I go about figureing out values for Q1? Would I use Ohm's law, Kirchoffs...
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    has to do with my transistors post below

    Ok everyone i tried my best to figure this out, but I came up with nothing. It's sort of hard to search the internet for parts with certain specs, especially transistors. So I need some help from you guys. Basically this is a schematic for a (crappy)laser pointer detonator I'm making, just for...
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    transistors

    I have a few questions about transistors, so here we go: How can you tell how much current must flow between base-emitter to allow current to flow collector-emitter?? How can you tell which connector on a transistor is the emitter? When a transistor gets a small current running through the...
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    Infrared phototransistor

    Ok, i built this infrared emittor using three 1.6v 50mA 100mW infrared leds, with a 100ohm resistor, and a 9v battery all in series. I did all the math and i bought the parts, soldered them and glued down the connections so that they dont move aroudn a whole lot, and it works great. Each led...
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    conventional schematic help

    Ok, I've learnt how to read electronic schematics in electron-flow style, and now that I've finally learnt it pretty decently I figure out that there's a whole different style? Conventional flow eh? Hmph. It makes absolutely no sense to me. How can people stick with that ancient method of doing...
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    Radio Controlled Switch for Ignition

    Ok heres my idea, and it's probably been thought up 10000000s of times but I'm just wondering if this would work and if anyone has any ideas on how to make this: A radio frequency transmitter (probably either 27 or 49 mhz
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    SUPER CONFUSED =\

    http://www.teachers.ash.org.au/jfuller/test2/diodesB.htm on that page, if you scroll down there is a picture of a grey box with little red lines on it. below that there is a tiny little schematic. I'm having a LOT of trouble getting all this through my brain..I'm a complete newbie to...
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