Magnasphere's TW series is used in the security industry for door and window sensors in closed loop alarm systems. It has a wider actuation zone in the X or Y axis than other Form A Magnasphere switches. Its robust, all-metal construction is highly resistant to magnetic tamper and defeat as well as permanent contact welding from power surges.
The basis of the technology is a magnetic sphere or ball contact housed in a durable metal housing. Completing the switch is a seal that contains the contacting electrode, which is insulated from the metal perimeter by a ceramic-to-metal bond. The case or seal provides the second contact point required to complete the electrical circuit. The seal/electrode cap is welded to the housing in an inert atmosphere, providing a hermetically sealed contact. Post-assembly magnetizing activates the magnetic properties of the contact.
Construction: Non-ferrous metal housing, compression seal hermetically sealed, protective gas atmosphere, precious metal plated spherical magnet contact.
Soldering Guidelines: 600°F (315°C) temperature iron for 5 sec. (max.). Not to be soldered to within 1/8" (3mm) of glass seal. Lead pins precious metal plated for enhanced solderability.
Termination Polarity Guidelines: Polarity selection is non-critical, though some life gain may be realized by center pin as cathode on logic loads, but center pin as anode on larger loads.
Leadwire Cutting / Bending Guidelines: Cut length has no effect on magnetic OP/REL values. Shearing action type cutters are recommended. End nippers and side cutters are NOT recommended. Metal-style seals are extraordinarily rugged, but the bending of unsupported lead wire pins adjacent to the glass seal is not recommended. For example, when bending, use the support of some type of parallel jaws spaced away from the glass seal to grip the lead wirepins while bending the pins' free ends so that no bending strains are imposed on the glass seal.
- Hermetically sealed contacts
- Non-contact operation
- Robust metal construction
- Magnetic anti-tamper
- High voltage EMI resistance
- Wide operating temperature range
- Intrinsically safe for use in volatile atmospheres
- Compact size
- Low cost ferrous proximity sensing
- High-stress applications that require a more robust switch such as small-engine oil level sensing, off-highway vehicles, and automotive
- Applications with high levels of electromagnetic interference (EMI) such as generators and motors
- High-volume applications that require automatic insertion or surface-mount printed circuit board assembly of insert molding such as utility metering devices and automotive switches
- Non-defeat anti-tamper applications such as industrial equipment, utility metering, and safety interlock