Final answer:
A switch-based control system enables device operation by altering the resistance within an electrical circuit to open or close the current loop, controlling the flow of current and thus the operation of the device.
Step-by-step explanation:
The type of control system that provides device operation by opening or closing an electrical current or voltage loop is commonly referred to as a switch-based control system. A switch can have a variable resistance, which is nearly zero when closed, allowing current to flow through the circuit, and extremely large when open, which stops the current from flowing. This is analogous to a valve in a water system that controls the flow of water through the system.
Switches and capacitors are examples of circuit elements included in such a control system. A closed switch acts as part of the wire and current passes through it with no loss of voltage, while an open switch prevents the flow of current entirely. For example, when you turn on a light using a light switch, you are closing the electrical circuit, allowing the electric current to flow and power the light bulb.
In electric circuits, direct current (dc) systems have a constant source voltage while alternating current (ac) systems have a source voltage that varies periodically. A device such as a battery, generator, or wall outlet creates a potential difference that drives current. Ohm's Law states that the current through most substances is directly proportional to the voltage applied.