1 uF Capacitor discharging into a 2uF capacitor

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In summary, this individual is having trouble understanding how to plot the voltage across two capacitors vs. time after a switch has been closed. They are unsure of the math behind the problem and are looking for help.
  • #1
Lefty806
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This is a variant of the classic capacitor discharging into a capacitor problem and I’m having some trouble reasoning it out to my satisfaction…

2 parallel capacitors (one 1 uF and one 2uF) with a switch and a 100 Ohm resistor between them. The 1 uF capacitor is charged to 100V and the 2 uF capacitor is discharged. I’m trying to draw plots of the voltage across each capacitor vs. time after the switch closes. I feel a bit stuck on the math for the unequal capacitor values and the impact on the time constants and voltage levels, but maybe I’m just over-thinking it. Thanks in advance for any insight.
 
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  • #2
Lefty806 said:
This is a variant of the classic capacitor discharging into a capacitor problem and I’m having some trouble reasoning it out to my satisfaction…

2 parallel capacitors (one 1 uF and one 2uF) with a switch and a 100 Ohm resistor between them. The 1 uF capacitor is charged to 100V and the 2 uF capacitor is discharged. I’m trying to draw plots of the voltage across each capacitor vs. time after the switch closes. I feel a bit stuck on the math for the unequal capacitor values and the impact on the time constants and voltage levels, but maybe I’m just over-thinking it. Thanks in advance for any insight.

Hi Lefty806, welcome to PF.

You'll have to show the details of your current attempt(s) in order for us to see how to help you.

EDIT: To start with, note that the capacitors are NOT actually in parallel since there is a resistor between one of the pairs of capacitor leads -- the capacitors are not actually connected to each other at both ends.
 
  • #3
Can you show your circuit diagram
 
  • #4
Thanks for already replying. I will post what.
 
  • #5
Sorry, mobile website mistake on my part...
I will post what I can in regards to previous work and a schematic as soon as I can. Couple hours or so.
 

FAQ: 1 uF Capacitor discharging into a 2uF capacitor

1. What is a capacitor and how does it work?

A capacitor is an electronic component that stores electrical energy in the form of an electric charge. It consists of two conductive plates separated by an insulating material called a dielectric. When a voltage is applied to the plates, an electric field is created, which causes one plate to accumulate positive charge and the other to accumulate negative charge.

2. How does a 1 uF capacitor discharge into a 2uF capacitor?

When a 1 uF capacitor is connected to a 2uF capacitor, the two capacitors share the same circuit, allowing them to exchange charge. The 1 uF capacitor will discharge its stored energy into the 2uF capacitor until both have the same voltage. This process is known as capacitor coupling.

3. What happens to the voltage and charge of the capacitors during discharging?

As the 1 uF capacitor discharges into the 2uF capacitor, the voltage across both capacitors will decrease. This is because the charge is being shared between the two capacitors. The total charge in the circuit remains constant, but the distribution of charge between the two capacitors changes.

4. How long does it take for the capacitors to discharge?

The time it takes for the capacitors to discharge depends on the capacitance values and the resistance in the circuit. The larger the capacitance and the lower the resistance, the longer it will take for the capacitors to discharge. The time can be calculated using the equation t = RC, where R is the resistance and C is the total capacitance of the circuit.

5. What are the practical applications of capacitor coupling?

Capacitor coupling is commonly used in electronic circuits to transfer signals from one stage to another without losing the original signal strength. It is also used in power supply circuits to smooth out fluctuations in voltage. Additionally, it can be used in audio circuits to block DC signals and allow only AC signals to pass through.

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