ovikytkimiä

Ovikytkimiä, also known as door contacts or magnetic switches, are simple electrical devices used to detect whether a door or window is open or closed. They are commonly employed in security systems and home automation. The most typical configuration consists of two parts: a magnetic reed switch and a magnet. The reed switch is usually mounted on the door frame, and the magnet is attached to the door itself, positioned so that when the door is closed, the magnet is close enough to the reed switch to activate it. When the door is opened, the magnet moves away, deactivating the switch.

There are two primary types of reed switches used in ovikytkimiä: normally open (NO) and normally closed (NC). A normally open switch remains open when the magnet is present and closes when the magnet is removed. Conversely, a normally closed switch is closed when the magnet is present and opens when the magnet is removed. For security applications, normally closed switches are often preferred. This is because if the wiring to the sensor is cut, it will register as an open door, triggering an alarm.

Ovikytkimiä are powered by low-voltage electrical current, often from a central security panel or a battery. When the state of the door changes, the ovikytkin sends a signal to the connected system, indicating the change in status. This signal can then be used to trigger alarms, turn lights on or off, or initiate other automated actions. Their simplicity, reliability, and low cost have made them a ubiquitous component in residential and commercial security and automation.