How Floor-Mat Alarm Circuits Work

Floor-Mat Alarms

• Floor-mat alarms are triggered when a person steps on the mat. They're used for security systems for the home, as part of the perimeter defense of the property, and at the entry for shops and offices. Hospitals and health-care facilities use them to monitor patients' movements without physical or chemical restraints. Different alarm sounds are available, according to the circumstances, such as standard alarms for security systems, and chimes and bird sounds when used for commercial and health-care settings.

Alarm Circuits

• Electricity flows on a pathway, or circuit, between opposing charges -- positive and negative -- in a closed loop. Opening or closing the circuit turns electricity on and off. Alarms use either closed or open circuits. In a closed-circuit system, electricity flows until a movement, such as opening the door, interrupts the circuit, which triggers the alarm. In an open-circuit system, the flow of electricity is blocked until the door opens and completes the circuit, and that starts the alarm.

Floor-Mat Alarm Circuit

• Floor-mat alarms use an open-circuit system. Two metal strips are placed underneath the mat, held apart slightly with a spacer, such as a foam-rubber pad. When someone steps on the mat, the pressure pushes the strips into contact, completing the circuit and sounding the alarm. The alarm is usually wired to a small sound box, which can be located within a specified radius of the mat. The most secure type of alarm box has its own power supply, and has to be turned off.

Variations

• Variations add to the effectiveness of the alarm, with adaptations for different situations. Several alarm boxes or chime units can be installed, desirable for health-care facilities or caregivers at home. A floor-mat alarm can also be wired to trigger the paging system in a hospital. Mats can be weather-resistant and slip-resistant, and even reversible. They're placed by the door, or the bedside when used to monitor patients. When used for security, the floor-mat alarm supports the complete alarm system.