# capacitance

1. ### fundamental behavior of capacitor's plates and the charges in response to sudden changes in voltage?

Hello everyone, I have been trying to understand fully the behaviour of the capacitor and over its two plates when exposed to sudden changes in voltage, and I divide my request for help into two questions: 1- How and why when we apply a sudden voltage over a capacitor C1_Plate_1, the C1_Plate2...
2. ### Formula for calculating capacitor balance resistor values

$$R_{balance} = \frac{NV_{rate} - V_{bus}}{I_{maxleak}}$$ N is the number of capacitors in series Vrate is the rated maximum voltage for any one capacitor Vbus is the bus voltage (the expected voltage across the whole series of capacitors) Imaxleak is the maximum leakage current Rbalance is the...
3. ### Parallel RLC circuit issue

I have been struggling with this issue: https://electronics.stackexchange.com/questions/647796/why-doesnt-the-voltage-at-the-resonance-frequency-go-above-the-input-frequency Does anyone have an idea why that is the case
4. ### What is the function of high current induction heater circuit elements?

Note: English translation is below. Herkese merhaba, Bu devrede komponentin görevleri nelerdir? Örneğin: - Dirençler ne işe yarar? - Bu devrede diyotlar ne işe yarar? - Toroid sargılarının sayısı artarsa ne olur? - Birden fazla kondansatör paralel bağlanırsa ne olur? - Devrenin verimli...
5. ### Led dim to bright then bright to dim in a flip flop ne 555

Hi all, above picture is a ne 555 flip flop circuit (1 off, 1 on) and vice versa. Lets say the red led receives an input (1) that is a constant dc voltage, how do I make the red led to go from dim to bright and then from bright to dim and vice versa with the blue led? Are there any schematic...
6. ### Ferrite bead vs Bypass Capacitor

Why we are using ferrite bead and bypass capacitor, if both are for removing noise? Can you explain why we are using both in the circuit and difference between using them, and where we need to use and how to calculate it?
7. ### Schmitt Trigger with Constant Current Source.

Hi All, To realise the below circuit I designed a circuit in MultiSim and tried ti simulate. But I'm unable to do so. I would appreciate any help in this regard.
8. ### Battery Hot Swap Circuit with Capacitors

Hi everyone, I'm trying to design a circuit whose battery can be hot swapped. I have a 3.6V battery connected to a boost converter, outputting 9V. I'm powering a small computer that requires a 9-20V input, and at idle consumes ~10W. I figured that, so that the computer stays on for 10s (with a...
9. ### SMD Capacitor selection

Hello everyone, How can we calculate the voltage rating of an SMD ceramic capacitor. Is it dependent on the package size?.
10. ### Capacitance and Inductance of twisted pair cable

In one of the article of "All About Circuits" about capacitance and inductance of twisted pair cable i found a set of formulae for computing capacitance and inductance of twisted pair cable based on diameter , spacing and dielectric constant as seen in the snapshot.. Can anybody give me the...
11. ### Buying a new multimeter: how important is hFE?

Hey, I'm buying my second, better, multimeter (first one costed 3 € : ) ) and I have this checklist: * auto ranging * capacitance measurement at least up to 10mF (I see a lot under 1mF and that sounds pretty useless) * ? hFE - how important is this one? It sounds pretty useful to me * I've...
12. ### VHF oscillator circuit w/ large frequency range and change according to capacitance value

Hello, It's my first post. I'm new in electronics fields. I'm french and my english is not very good, excuse me. I want to make a VHF oscillator(~ 30 MHz) that his frequency can change with the value of the capacitance. I found in an another post the RF2506 which seems to works but it's...
13. ### What is Cmeu in an npn BJT operating in saturation mode ?

I know Cmeu is parasitic capacitance in active mode. It's the B-C junction capacitance. But does it change when the npn is operating in saturation mode? Also in general(not just in saturation mode) what happens to Cmeu at increasing Vce? Does it increase? What other things happen to the...
14. ### How to measure capacitance with high series resistance

I have a sensor that can be modeled as a capacitor and resistor in series. The problem with this resistor is the resistance is on the order of 10's MOhm and the capacitance (we believe) is single pFs. I have tried using a resonant circuit to find the capacitance, but the results end up super...
15. ### Measuring DiElectric constant of organic varnish using parallel plate capacitor

Hi, am facing a strange issue. In brief, the objective is to measure di-electric constant of a varnish film (approx 30micron) applied to a copper plate. To achieve this, i have made a capacitance meter (using a CC Bridge method) where the electrodes are two brass plates of 11cm diameter, between...