Rated voltage The maximum voltage at which electric component can operate for extended periods without undue degradation or safety hazard.
Rectifier A solid-state electrical device that will allow current to flow in one direction only. It is designed to convert alternating current to direct current.
Reader A device that obtains data from an access credential (card, tag, etc.) and send the data to a controller for an access decision. (Some units combine reader and controller in one device.)
Recycle time The time needed to reset and rein the timing function and remain within the specified timing tolerance. Recycle time is generally specific "during timing" or a "after timing".
Regulated power supply A power supply provides a constant output regardless of voltage variation.
Relay An electrically controlled device that opens and closes electrical contacts to effect the operation of other devices in the same or another electrical circuit.
Remote alarm A visual or audibly signaling device used to signal violations at locations removed from the central control station or monitored open. For example, a remote alarm may be placed roof, in a stair tower, or at guard station outside a building.
Remote reset A switch located at a monitored opening. If a violation occurs, the alarm at the control console can not be turned off until the?? is secured and the remote reset is activated. Its purpose is to ensure the inspection of an opening that has been violated or left open.
Reset time The time required to return the output to its original condition.
Resistance The opposition to the flow of an electric current (measured in ohms); the reciprocal of conductance.
Resistor A circuit element whose chief purpose opposes the flow of current, causing a decrease in voltage.