While security and life-safety are the most critical issues that must be addressed, convenience is a luxury every user and building owner desires. Automated openings make operation of the door very convenient. New technology allows an opening to be monitored from anywhere in the world via the Internet. In addition to security, life-safety and convenience, other benefits include better access, egress control and more efficient operation. With electronic keys, an employee is unable to simply walk into a hardware store and cut extra keys to the office. These keys are controlled by a computer which is monitored by the person responsi-ble for the maintenance of the system. The control offered by electronic keys allows the person in charge to be made aware that a key has been lost or mis-placed and that key be removed from the system. There are four components required in an access control system; these compo-nents are: The power source, load, control and conductor. Power Source The power source, also known as the power supply, ensures proper voltage, which is a term used most often to describe the electrical energy that causes current to flow in a conductor, similar to pressure in the water pipes in a plumbing system. The power supply also ensures that the proper current — alternating current (AC) or direct current (DC) — is present in order to properly operate the system. The amp, which is a unit of measurement for the rate of electrical current, is the last piece of information required in order to specify the proper power supply. The power supply has a transformer, which takes in the high voltage from the power company and reduces it down to the low voltage required by the load, and the rectifier within the power supply changes the current and converts the voltage to DC. Power supplies should be specified with capacitor filters and regulators that will ensure the correct voltage output required for the device. If the device requires 24 volts of DC and there is no capacitor filter and regulator, the output could be too high or too low, which will either not allow your device to operate properly if at all or burn it out, requiring replacement. The last point regarding the power supply is the amps. The power supply must be specified with the amps equal to or greater than the device. If the device requires one amp, the power supply must be able to handle at least one amp if not more; if more is available, addi-tional devices can use the same power sup-ply, also depending on other factors such as the conductor gauge and distance. A battery backup option is available for systems that are not required to be tied into the fire alarm system. This ensures that the system will remain operational during a power outage for as Circle Product Information no. 204 on page 32 www.cmmonline.com 31
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