How many basic types of magnetic reed switch sensors exist?

The correct answer is that there are two basic types of magnetic reed switch sensors, which are classified based on their construction and application. These two types are generally known as normally open (NO) and normally closed (NC) reed switches.

A normally open reed switch remains open (non-conductive) until a magnetic field is applied, at which point it closes in response to the magnetic field. This type of switch is commonly used in applications where the circuit should be completed only when a magnet is present, such as in door and window sensors for intrusion detection.

Conversely, a normally closed reed switch starts in a closed state (conducting) and opens when a magnetic field is applied. This type is useful when the circuit is intended to be active until interrupted by the presence of a magnet.

These distinctions in functionality are fundamental for designing security systems and determining how magnetic reed switches can be integrated into various applications, thus highlighting their importance in intrusion detection systems.