# Tagged Questions

Capacitance is the ability of a body to store an electrical charge

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### 'How/why' does a human act as a capacitor for a theremin?

I've read that a human plays a theremin by acting as a capacitor, or reducing the capacitance of the theremin. What properties of a human make it act this way? Is there any way of reducing/negating ...
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### Energy stored in the capacitor increase when the capacitance decrease [on hold]

Help!!!!Energy stored in the capacitor increase when the capacitance decrease.Suggest an explanation for this energy increase, making reference to conservation of energy. Question [paper 3,Q4(D)(ii)] ...
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### Equivalent capacitance for Darlington

In a Darlington pair of BJTs, it is known that equivalent parameters of a unique transistor can be found ($r_{\pi}$, $r_{o}$, $g_{m}$). But what about its capacitance? Is it possible to replace ...
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### How to use BSIM3v3 capacitance for hand calculation?

As you all probably know, capacitances in BSIM3v3 are just the partial derivatives of the terminal charges with respect to the terminal voltages. They are not physical two terminal capacitors. Cij = ...
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### Why does 7.6Mhz signal start appearing?

I am using a reference design that modulates a 8Mhz carrier DC square wave in simple on-off keying at 10bps. I wanted to change the carrier to 125kHz. I took out the 56pF capacitor in C4 and ...
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### Is it practical to measure an unknown capacitance by measuring its impedance?

I've recently seen some fourth year engineering projects at my school (University of Waterloo) and one that I found interesting was this novel pressure sensor that uses nano silver separated by a di-...
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### Cable-to-cable crosstalk (Capacitative Coupling)

I'm having some difficulty understanding the solution to this question. Compute the cable-to-cable crosstalk due to capacitive coupling in a harness between two cable pairs having an average ...
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### Capacitive touch insulation problem?

I have an "U" shaped metal profile that is 2 meters long each side is 1.5 cm. It is sprayed with acrilic color. and i want to use it as indirect light profile/enclosure for a 12v Led strip. While ...
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### Does this speed controller alter resistance or capacitance?

The attached image is of a ceiling fan speed controller module I brought online. It seems the attached circuit mainly consists of some capacitors. This makes me believe that the 4 different settings ...
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### Sensing a touch of a metal

Assume there is a piece of metal. I would like to identify, with a microcontroller, if another metallic object is touching this piece. I want to apply this for a smart hook that "knows" if a ...
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### Why do we use two parallel capacitors in a voltage regulator circuit? [duplicate]

C1 and C2 are parallel capacitors and their total capacitance is 1000.1 uF. I think C1 is ...
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### C4D capacitively coupled electrode sensing - circuit simplification

I am trying to make a detector to pick up small changes in capacitance. Basically both electrodes have a common ground and are closely spaced. One is driven by oscillator at 0.1-1MHz and the other one ...
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### How to find the sketch energy of the capacitor (let's say versus time) with the q-v plot shown below?

I wonder what is the plot of the energy of the so-called capacitor,it's will be 0 except in 2 and 3 that is a delta function but when we want to calculate it's energy we don't know the exact value of ...
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### If the voltage doesn't kill you, does the current capability matter?

Trade electricians often work on live household circuits carrying 120V AC. I've gotten shocked by accidentally touching such hot wires often enough to recognize the 60Hz AC buzz. Fortunately, human ...
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### Find the equivalent capacity of this circuit [closed]

I wonder how to obtain the equivalent capacity of the circuit below.I think adding a voltage source and using KVL would be a nice idea but I don't know how to apply it.any hints would be appreciated.
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### Glove Breach Detection

I'm trying to design a circuit that would be fitted inside large plastic gloves. That when the gloves are cut the circuit produces a signal. Currently I'm considering having a metal (probably ...
I know that equivalent capacitance of multiple capacitors in series is $$C = \left(\frac{1}{C_1} + \cdots + \frac{1}{C_n}\right)^{-1}$$ and in parallel is $$C = C_1 + \cdots + C_n.$$ But there are ...