i'm taking a course in Switched-mode power supplies and I am a bit confused about the theoretical explanation of what is happening in increasing voltage using a bootstrapped capacitor.
You connect a capacitor with a +Vdd. This places a charge +Q on one side and -Q on the other side of the capacitor. You then apply +Vdd to the other plate and use a diode on the other to stop the current flowing. 1)
- You've then surely got +Q on both plates now. Or is that even right?
- This confuses me a little further, if the equation for a capacitor is Q = CV, is Q in this equation the amount of charge that can be placed on one plate, i.e. +Q, or the total difference +Q and -Q, i.e. equal to a difference of 2Q?
- I read in multiple sources that a capacitor is the same as an inductor and it's voltage cannot change instaneously, in a similar way an inductor's current cannot change instaneously. However the latter's is due to the magnetic field collapsing, And I do not see anything happening to the electric field?
I think my problem probably lies in the definition's of these quantities and what is happening to the charge on the capacitor's plates and the electric field between them but cannot figure out what.
Please see an example circuit below of where this is applied.