Capacitance - Capacitance And Direct Current

In a direct-current circuit a series capacitor will permit only a single pulse of charging current when the circuit voltage is changed. The charging current in quickly falls to almost zero as a capacitor charges from a constant-voltage source. Capacitors are sometimes used in circuits to oppose direct current. They may block direct current while simultaneously passing a superimposed alternating currents. A blocking capacitor is commonly used to separate alternating and direct current components.