Reed switches from masetec

Unfortunately not, or at least it is risky. In reed technology, as in other areas, efforts are made to avoid a simple switch from one manufacturer to another. Many factors matter here, such as the number of turns in the respective test coil. A coil with 5,000 turns naturally has a different value than one with 10,000 turns.

Exactly—good attention! AW stands for ampere-turns and is probably the most important value in the reed world, as it defines sensitivity, i.e., the switching distance. Please note: an AW value of, for example, 10–15 AW is often equated with a switching distance of 10 to 15 mm, which is absolutely incorrect. The sensitivity of reed switches is determined in predefined coils. By applying a voltage to the coil (current flow) with a defined number of coil turns, a magnetic field is generated. If I then increase this current until the contact closes, I have determined the pull-in value (A × W). If the current is then reduced until the contact opens again, this results in the drop-out value.

Good question! A reed switch installed in a housing is generally referred to as a reed sensor, whereas the uninstalled reed is the switch.

This is, of course, the most important question, because this knowledge opens up countless applications.

Two contact blades made of ferromagnetic material are hermetically sealed into a glass tube under an inert atmosphere (e.g., nitrogen). After the sealing process, the overlapping contact blades inside the glass body form an air gap in the contact area. For improved switching behavior, the two blades are coated in the so-called contact zone with ruthenium, rhodium, or iridium. The key point, of course, is that when exposed to a sufficiently strong magnetic field, the two contact blades assume opposite polarity and thus close the contact.

Most reed switches/sensors are so-called SPST-NO (Single-Pole Single-Throw, Normally Open) types and are also referred to as Form A switches (normally open contact). However, many reed-based applications require an SPST-NC (Single-Pole Single-Throw, Normally Closed) or Form B (normally closed contact). In addition, SPDT (Single-Pole Double-Throw) or Form C (changeover contacts) are indispensable in numerous applications. In a few products, bistable switches—also known as Form E or latching—are used.

We know that every application requires different distances. To achieve these, we can either adjust the AW value, use a stronger or weaker magnet, or even adapt the magnet material. Revising the position of the magnet relative to the reed could also lead to the desired result. You can find information in the download area about the different approaches and the resulting changes in switching behavior.

We know how difficult it can be to modify reed switches—this is why we offer this service. Whether trimming, bending, or other adaptations: there are numerous ways to tailor reed switches precisely to your requirements.

No—of course not. We can adapt our reed switches to your application.