Activity for Andy aka
| Type | On... | Excerpt | Status | Date |
|---|---|---|---|---|
| Comment | Post #286809 |
It draws 6 uA current and that will still deplete your battery. I'd be concerned about that but sure, in principle, that's the sort of comparator idea that fits in with my thinking. Check that it can handle supplies as high as 9 volts and, regards the resistor values, there should be enough informati... (more) |
— | almost 3 years ago |
| Edit | Post #286809 |
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— | almost 3 years ago |
| Edit | Post #286809 | Initial revision | — | almost 3 years ago |
| Answer | — |
A: Battery protection circuit > What kind of IC can be used to drive the MOSFET, so that when the voltage drops below 6.2 V the battery disconnects from the load? That reverse protection MOSFET works fine for reverse protection but, it cannot be used to turn-off the load when the battery is correctly connected. Look closely... (more) |
— | almost 3 years ago |
| Comment | Post #286792 |
The op-amp (beyond its local feedback) needs to have a resistor in series with the output that feeds the first inductor L1 else, it's not a Hartley oscillator. Please learn how to draw schematics correctly. (more) |
— | almost 3 years ago |
| Comment | Post #286793 |
Actually, to make this circuit work correctly, you need theoretically an extra resistor to ensure that the pi-network behaves like a 3rd order filter and not a 2nd order filter. This means that the op-amp MUST have output resistance (despite the circuit showing none). I mean, what's the point of the ... (more) |
— | almost 3 years ago |
| Comment | Post #286745 |
Yes, you could make a converter using a BJT oscillator and a transformer connected to a rectifier and smoothing capacitor but, it would be low-powered, inefficient and have poor regulation so, why would you bother? (more) |
— | almost 3 years ago |
| Comment | Post #286738 |
A BJT doesn't have a CE junction; it has a BE and BC junction. The yellow line you drew is too simplistic as is the graph you drew it over. Each curve in that graph has a differently sloped saturation region like [this](https://it.mathworks.com/help/examples/sps_product/win64/ee_npn_02.png). This mea... (more) |
— | almost 3 years ago |
| Comment | Post #286724 |
R/L is actually \$4\pi\$. You have inadvertently chosen to work in radians/sec but you didn't convert Hz to rad/sec. Rookie error. Also, you didn't appear to understand that the basic relationship involved is this: \$Q=\dfrac{1}{R}\sqrt{\dfrac{1}{LC}}\$ and, Q is centre frequency divided by bandwidth... (more) |
— | almost 3 years ago |
| Edit | Post #286714 | Initial revision | — | almost 3 years ago |
| Answer | — |
A: Complex frequency of a pole > if we don't apply a sinusoidal signal at the input s may become a complex number $$$$ All real-world signals exist only on the \$j\omega\$ axis. Consider that a complicated signal can be broken down into a fundamental sinewave and its harmonics. The harmonics are still sinusoidal an... (more) |
— | almost 3 years ago |
| Edit | Post #286547 | Initial revision | — | almost 3 years ago |
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A: Unexpected impedance spike when paralleling capacitors I think you can make a pretty good case for the spike being caused by the addition of the 100n and 10n capacitors: - Image alt text > I assume that the solder blobs between capacitors introduced a series > inductance that in turn caused the spike in impedance at 8MHz. It can't be ruled out ... (more) |
— | almost 3 years ago |
| Comment | Post #286537 |
Your graph is for a PNP transistor yet you have drawn an NPN transistor (more) |
— | almost 3 years ago |
| Edit | Post #286493 |
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— | about 3 years ago |
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— | about 3 years ago |
| Edit | Post #286493 | Initial revision | — | about 3 years ago |
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A: Thévenins Theorem for Transistor Circuit > Is the Thevenin's Theorem being applied incorrectly for the circuit ? It's being applied inaccurately. The final Thevenin voltage should be 2.782 volts (rather than your calculated value of 2.61 volts). I calculate the Thevenin resistance to be 759 ohms (near enough to yours so that it doesn'... (more) |
— | about 3 years ago |
| Edit | Post #286435 |
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— | about 3 years ago |
| Comment | Post #286435 |
You can tweak the MOSFET VGS threshold voltage with the addition of a VSB voltage. See [this](http://cmosedu.com/jbaker/courses/ee420L/s15/students/yurgelon/lab8/lab8.htm) (more) |
— | about 3 years ago |
| Edit | Post #286435 |
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— | about 3 years ago |
| Edit | Post #286435 | Initial revision | — | about 3 years ago |
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A: What is this fourth connection in NMOS device? That fourth connection is the bulk/body/substrate connection: - Image alt text Image from here. On a normal 3 terminal MOSFET the "body" is connected to the source. On your device, the 3 n-channel MOSFETs share a common bulk pin that should usually be connected to the most negative voltage of y... (more) |
— | about 3 years ago |
| Edit | Post #286299 |
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| Edit | Post #286299 | Initial revision | — | about 3 years ago |
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A: What reactance actually is? "React" implies a response to an "event". - For an inductor, the "event" is a change in current, \$\frac{di}{dt}\$ - For a capacitor, the "event" is a change in voltage, \$\frac{dv}{dt}\$ $$$$ So, an inductor or capacitor will produce a proportional reaction (or response) to something c... (more) |
— | about 3 years ago |
| Comment | Post #286020 |
The maximum allowable level of the input voltage ripple is not calculated; it is something you, as an engineer decide upon. (more) |
— | over 3 years ago |
| Edit | Post #285994 |
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— | over 3 years ago |
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| Edit | Post #285994 | Initial revision | — | over 3 years ago |
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A: Why are some PCB design software programs considered to be 'hobbyist' programs? > Why are some PCB design software programs considered to be 'hobbyist' programs? Elitism and, folk with money to burn. I've used Altium, PADs, OrCad, Eagle and my current personal favourite is KiCAD. Yeah it's a bit messy on libraries but it's a small price to pay. I pretty much like Eag... (more) |
— | over 3 years ago |
| Comment | Post #285928 |
Mike, I'm not demanding anything and I have no interest in the politics of the site. (more) |
— | over 3 years ago |
| Comment | Post #285921 |
It seems a rather lame discussion to some of those on SE. I mean, recently one guy kept having a go at me and we both got banned for 5 days. Another more recent SE discussion got me banned for a week despite the idiot totally trying to misrepresent what I said in his answer i.e. his answer was all ab... (more) |
— | over 3 years ago |
| Comment | Post #285921 |
@#53110 cheers Mike (mike?) (more) |
— | over 3 years ago |
| Comment | Post #285921 |
@#53042 I'm happy to take a look at the carnage of your endeavours that happened before I joined. I'm also happy to give you my opinion on what you wrote but, I can be brutally honest sometimes so, if you are up for it, leave a link. (more) |
— | over 3 years ago |