What is the formula to calculate power in a capacitor circiit?

 

W = 0.5*C*V^2 --> divide both sides by 0.5*V^2

W/(0.5*V^2) = C

C = 180J/ (0.5 * 450V^2) = 1777uF

Q = C*V = 0.8C

 

W = 0.5*C*V^2 --> divide both sides by 0.5*V^2

W/(0.5*V^2) = C

C = 180J/ (0.5 * 450V^2) = 1777uF

Q = C*V = 0.8C

Just to be clear, W in these equations is energy in Joules stored on the capacitor, not power (which is energy per unit time).

If the capacitor is being charged and discharged at a specific frequency (f) then the power dissipated in the charge and discharge circuit in watts is f*C*V^2.

 

If the capacitor is being charged and discharged at a specific frequency (f) then the power dissipated in the charge and discharge circuit in watts is f*C*V^2.

Yep, any R-C snubber used in a switcher has power dissipation in the snubber resistor given by:

Freq x C x V (squared)

Doesn't matter what the Ohmic value of the resistor is, same power.

 

Yep, any R-C snubber used in a switcher has power dissipation in the snubber resistor given by:

Freq x C x V (squared)

Doesn't matter what the Ohmic value of the resistor is, same power.

It's also the power dissipated by an amplifier or digital circuit driving a capacitive load. Charging and discharging the stray capacitance on a circuit board or internally in an IC is the primary cause of power dissipation in CMOS circuits.