A capacitor consists of two mutually insulated metal plates or metal foils that face each other, and wound with insulating spacer. Its major feature is the capacity. The two-wire line is isolated with two very narrow strips of metal, compared against each other.
A capacitor or a capicity (C) operated with DC voltage has extremely high resistance. The current flow takes place when the capacitor is connected to a DC voltage, and the current is switched on. The flow decreases in an exponential function. In the steady state, with the capacitor fully charged, it is not possible to measure any more current flow.
A capacitor connected to AC voltage provides different results. It is measurable on alternating current, although no electrically leading connection is given over the dielectric. The electrons do not flow through by the capacitor, and rather oscillate between the generator and the capacitor’s surfaces back and forth. At alternating voltage the capacitor is periodically loaded and unloaded, or constantly reloaded. If one doubles the frequency, the resistance value halves itself.
Capacities are meassured with an LCR meter.« Back