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When I look at the datasheet for a 2N3906 manufactured by Fairchild (https://www.fairchildsemi.com/datasheets/2N/2N3906.pdf), I see on page 3 that it has an Emitter-Base breakdown Voltage of -5.0V. So if your SW12 switch is closed then you're applying 12V to the base of your 2N3906. Its emitter is tied to ground through RaT1-2, so you're effectively applying ...


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Page 2 of this datasheet tells the story. Under absolute maximum ratings it states that the maximum reverse voltage of base and emitter is 5V. You have exceeded this by using 12V and although the base-emitter region is probably still intact (due to the 100k resistors in your design) you can't expect leakage current to be insignificant. Don't expect ...


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This is expected. Edit: It's not leakage- you're breaking down the E-B junction in reverse by exceeding the breakdown voltage (typically rated at 5V with actual breakdown 6~9V). A p-channel MOSFET might give you what you want since the gate is insulated. There are also (somewhat rare) 'symmetrical' transistors that have equal E-B and C-E breakdown voltages ...


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You "feel like there's something missing" in the task... and you are right, there are missing two pieces of information to determine the required bias (\$ V_{GS} \$). From the given information you can write: $$ I_D = \frac{V_{DD}}{2 \cdot (R_S + R_D)} = \frac{k \cdot V_{DD} - V_{GS}}{R_S} = I_{DSS} \cdot \left(1 - \frac{V_{GS}}{V_P}\right)^2 $$ where ...


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-- "Old" question, I know, but still wanted to answer, on this, the eve of my return -- The filtering is most likely intended to keep the VDDCORE noise out of the VDDPLL, to increase its accuracy. As such the values are probably calculated for its likely-to-be-used core clock speed. Usually in the Design Checklist they use values that are calculated and ...


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As the comments to your question say, you need to find out a suitable capacitor value. You can then see what the valley voltage of your ripple is, add in the voltage drop caused by the rectifier diodes, then arrive at the MINIMUM transformer secondary voltage. You will then select the next highest available transformer secondary voltage, re-do all of the ...


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555 is not a right component for the task; it is okay to use for two LEDs, but things quickly get hairy for more than two LEDs. You need a Ring Counter + astable multivibrator (Examples of ring counters can be seen here: https://www.google.com/search?q=ring+counter+circuit&source=lnms&tbm=isch). You can try this one for example: ...


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How about an astable multivibrator? In a 2-LED configuration, they one is on while the other is off, and the frequency determined by your resistor/capacitor choice. You can find the schematic for a 2-LED astable multivibrator on the internet (wiki article here), and I don't see why it wouldn't work for 3 LEDs.


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I think you're going into far too much detail too early on. I've designed complex state machines many years ago and this kind of problem is going to be a bit tricky to get right. Step 1, is to get the behaviour right. Don't even think about assigning binary numbers to represent the states yet. Clearly from your postings, you haven't really got the whole ...


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Are depletion mode devices being made obsolete by the development of the technology of enhancement MOSFETs? No, I wouldn't say so. Depletion mode devices, like most discrete devices, are being made obsolete by the development of integrated circuits. As time goes on, ICs are developed for progressively more specialized purposes, reducing the need for ...


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You are asking way too many basic questions for this stage in your course. This means you didn't understand some previous material, but worse, it's clear you don't have any intuition and feel for circuits. With some hard work you can possibly muddle your way thru and eventually receive a degree, but that will be just a hollow piece of paper. I've ...


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Regarding the ICs, I think it is simply because of the compatibility with the manufacturing processes used. Threshold voltage of a MOSFET is controlled by technological parameters (concentration of dopants in the channel and oxide thickness), which are shared among all devices on the chip and hopefully the whole wafer. Insertion of a depletion-mode device ...


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Since it is class work, I am hesitant to say too much. Also, I am not an audio amp designer. But I would suggest Douglas Self's book on audio power amplifier design, since he also does not use MOS or IC's (such as op-amps). It may be the intent of your teacher that you all struggle through the trade-offs of different amplifier architectures. But there is ...


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Firstly, can I just say you haven't really provided enough information, and are also asking too much in one question. I would definitely suggest getting a book. A really good one is "the art of electronics". It has been the "bible" for a long time, and will give you a range of circuits from the most basic to more elaborate, with all the explanations, for ...


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"What, if anything, am I missing?" The main thing would be that you are using non-isolated boost regulators. With a non-isolated boost, the minimum output voltage will be Vin-Vd or in this case ~11.6V, since Vin is 12V and D1 and D2 are Schottky diodes. A transformer coupled Flyback or Sepic would be needed to have standby output voltages less than Vin. ...


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No, your feedback will not work. Your schematics has N-channel mosfets. They require gate to be more positive than source. In your design, when the system is on, you will have +24/+30v on source, and only 0/+12V on gate. Even if you change mosfets to P-channels, you will still have at least 12v across gate-source when system is on is open. You would not ...


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This is not a "real answer" yet. It may become one. But hopefully still useful. I'm getting around to getting around to playing with Rogowski coils as part of a larger project. The internet is full of references as you know doubt know, but Should be close to what is wanted DESIGN AND CALIBRATION OF ROGOWSKI COILS This looks extremely good - despite the ...


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You could use a voltage divider, but it will probably be simpler and safer to use a step down transformer to scale the mains voltage down to something the Arduino ADC can read. Make sure that you use an actual bare transformer that outputs an AC waveform and not a switching or rectifying power supply that outputs DC. You can use any transformer that brings ...


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I know this is an old question, but I am actually doing pretty much the same thing. I am designing an "80's style" console based on the Z80. What I have decided to use is the Propeller microcontroller from Parallax. https://www.parallax.com The Propeller (sometimes called "prop") has 8 cores that run at the same time. Each core is capable of displaying ...



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