Capacitors (Figure 21) are devices used to absorb and store electric current to prevent damage to components. These components are made of two conductor plates with a non-conducting material between them. Capacitors will store energy if the circuit is broken and will remain charged until the circuit is restored.
Capacitors are useful for absorbing stray currents and preventing arcing across opening contacts. Variable capacitors are called trimmers or tuners and are used only in very sensitive circuits with low current flow.