The new Spot-On sensor is designed like no other reed switch based proximity sensor. There are sensor assemblies that feature internal magnets but none like this one.
Other proximity sensors feature rectangular or square magnets arranged parallel to the switch and are housed in box like housings. They are activated when steel or a magnet align parallel to the box. The steel sensors previously available on the market were limited to low power applications (under 10 watts). The new Spot-On sensor is tubular or cylindrical in shape, features axially arranged magnets and is capable of 100 watts.
HOW IT WORKS
The internal ring magnets feature opposing magnetic fields held in a fixed position with a physical space between them (they do not move in response to the approach of the target). At the center of this physical space the magnetic force is balanced and creates a neutral position. The high powered reed switch is effectively centered in this neutral position. When the target (or magnet) approaches the sealed end the magnet closest to the target effectively becomes stronger and pushes the neutral position into the sensor housing, the reed switch goes active. Upon withdrawal of the target (or magnet) the neutral position returns to its balanced position and the reed switch deactivates.
Intended for activation with a steel target the Spot-On sensor can be activated with ferrous brackets, bolt heads, steel vanes (for precise and narrow on/off relationship) but also with a magnet. Depending on magnet shape, more specifically length, the Spot-On sensor can be activated at a gap of 3 inches (or more).
This design features no internal moving parts other than the reed switch armature. It is exceptionally resistive to axial shock and vibration (unlike the competitive product). The Spot-On sensor enjoys all the features of the internal hermetically sealed reed switch (giving it effectively a double seal environmentally (glass to metal seal and epoxy seal at wire exit)). Reed switches are known to go millions of cycles as they have virtually no moving or sliding components.
Spot-On is innovative enough that it is the most recent and most ingenious to receive a patent in many years that features a reed switch. Hermetically sealed, explosion proof, fast activation, very impressive! It can be scaled down in size to a much smaller diameter if an application warrants that. It can be scaled to feature multiple reed switches into double-pole-double-throw, triple-pole-triple-throw; all being activated simultaneously by One Actuator Event (steel or magnet approach).