Comment by periblepsis on Solving for equivalent resistance and flow of current
No, your idea does not work. There will be a current in the \$25\:\Omega\$ resistor if you apply a voltage source or current source across the \$4\:\Omega\$ resistor. So you just got lucky with your...
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Answer by periblepsis for T and Pi model of Common Emitter Amplifier
non-linear DC-only bipolar modelThese models come from two of the original three equivalent non-linear level-1 models of the bipolar transistor: the hybrid-\$\pi\$ (note: \$\pi\$-model) and the...
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Answer by periblepsis for Solving for equivalent resistance and flow of current
Create the following circuit:simulate this circuit– Schematic created using CircuitLabUse KCL:eqA = Eq( Va/R1 + Va/R4 + Va/R5, Vn/R1 + Vb/R4 + Vc/R5 + I1 + I2 + I3 ) # KCL VaeqB = Eq( Vb/R2 + Vb/R4 +...
View ArticleComment by periblepsis on High speed switching between two power supplies for...
Do you have a datasheet on the higher speed valve?
View ArticleComment by periblepsis on Identify the component: stack of metal plates
I think I see four tabs on it. If that's right, then likely a bridge rectifier. It does have the vague appearance of a selenium rectifier. But I have to admit that all of those I have here are bolted...
View ArticleComment by periblepsis on Out resistance of Common emitter and common...
@Alex For the common emitter, the collector is treated as infinite impedance (current sink) unless the Early Effect is also added in (which it appears it is not in your example.) Because of that, the...
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Answer by periblepsis for Deriving initial condition for a series RLC with...
I'll stay completely in the time domain.In my own way of writing:$$\begin{align*}R_1\,i+\frac1{C_1}\int i\:\text{d}t+L_1\frac{\text{d}}{\text{d}...
View ArticleComment by periblepsis on Why exactly is capacitance equal to both Q/V and εA/d?
I'd recommend the latest version of "Matter & Interactions" by Chabay and Sherwood. It covers everything you need to know about capacitors and the physics, without getting overly deep into the...
View ArticleComment by periblepsis on Capacitor Limits Output Signal from Class AB Amplifier
@AlfieWren-Swords What in the heck are you doing in the red-circled area here??? And what's driving the orange-circled area??? I get it that you have a long-tailed pair to start -- okay. I see that you...
View ArticleComment by periblepsis on What exactly causes current to flow through a...
This is all completely covered, in depth, in "Matter & Interactions" by Chabay and Sherwood, 4th edition (and earlier ones, too.) It takes just a few nanoseconds to set up the surface charges...
View ArticleComment by periblepsis on Modeling Electret in a simulator
I use something like this in LTspice. Let me know if anything there doesn't make sense. (Or if the whole thing misses your point.)
View ArticleComment by periblepsis on Common base Colpitts oscillator producing two...
Doesn't surprise me at all. I used to listen to such effects, tuning my radio and finding varying volume of the exact same transmission at 5 or 6 different places in the same band and definitely not...
View ArticleComment by periblepsis on Capacitor Limits Output Signal from Class AB Amplifier
@AlfieWren Yes, you can try and build it. That's why I added the emitter degeneration and used a reasonable current source. Just do NOT use a solderless breadboard. The CE stage you pasted into that...
View ArticleComment by periblepsis on Get a analogue voltage from a PWM signal to emulate...
@Skele_C I get a minimum of \$\frac{12\:\text{V}}{1+\frac{240\:\Omega}{40.5\:\Omega}}=1.73262032\$ and a maximum of \$\frac{12\:\text{V}}{1+\frac{240\:\Omega}{281\:\Omega}}=6.47216891\$. But it is...
View ArticleComment by periblepsis on Calibrating phase shift of multiple RF circuits
I have very little experience here. But I imagine others do about what you did -- careful construction to within some tolerance -- followed by measuring the relative phases and amplitude differences...
View ArticleComment by periblepsis on Bjt but no value given for Beta or alpha
If the voltage drop across RB is less than 100 mV then this would mean 4.9+ V across the forward-biased BE junction of the NPN on the left. That will result in an insane amount of base current, limited...
View ArticleComment by periblepsis on One-Key Power On/Off Circuit Analysis
Normally, a long-press / short-press thing is done with an MCU. But if you don't want to program, you could look at this answer.
View ArticleAnswer by periblepsis for Resistances seen by the source and load in an...
For the circuit you've shown us, a CC arranged topology with a bipolar transistor, the input capacitor is usually taken as a wire (for AC purposes) and isn't counted in the input...
View ArticleComment by periblepsis on If you were to start out to build a class AB...
AHX123, I just wrote something here. Whether or not it is of use to you is another thing. I doubt you are ready. But it describes about what you are looking for, I think.
View ArticleComment by periblepsis on Calculating Vab Without Reducing the Circuit Using...
Turing, is the idea of turning off sources allowed? You have three of them. So you'd sum up three results to get the final result. Or are you sure that source transformation must be used, exclusively?...
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