10-23-2014 Capacitors and capacitive circuits

A Capacitor is a device that stores electric charge and electrical potential energy.

• Capacitance is a measure of the ability of a device to store charge per unit of voltage applied across the device

This is the application of kirchoff's law. These capacitors are in parallel and they in turn have a negative effect on each other, this is the opposite of the effect of resistors in parallel, in which they total to a greater resistance.

The capacitance of a given capacitor is defined mathematically as the ratio of the magnitude of the charge, q, on either one of the conductors to the voltage, V, applied across the two conductors

Michael Faraday. Total Badass. 

Don't sleep in class. Ever. This shows that some capacitors or some circuits can be simplified just by redrawing them to recognize what is in series and what is in parallel.

• Given some circuit containing only capacitors, the objective is to find the capacitance of a single capacitor that has the same capacitance as combined capacitance of all the capacitors in the circuit. The combination of capacitors can then be replaced by its equivalent capacitance.
• The next step is to decide which capacitors are in series and which are in parallel - Series and Parallel Connections.

By using the rules of parallel and series capacitors you can reduce the various sub-combinations until you are left with a single capacitor

The exercise shows the charging and then discharging of a capacitor. How it charges very quickly and discharges very quickly, yet theoretically never gets fully charged or fully discharged.  

In this experiment, the capacitance is monitored so that a rate can be established for charging and discharging, and a relationship between Voltage and time can be seen.