GENERAL SPECIFICATIONS KJT's SNG-S Series Speed Sensors use a magnetically biased Hall-effect integrated circuit (IC) to accurately sense movement of ferrous metal targets. The specially designed IC and a permanent magnet are sealed in rugged, probetype packages. The IC detects the alteration of the magnet's flux density when it is approached by ferrous metal. A sensor positioned at the circumference of a revolving gear wheel detects the teeth and spaces, and supplies a digital pulse output with frequency proportional to gear wheel speed. Optimum performance is dependent upon a combination of variables such as target material, geometry and speed, sensor/ target gap, and environmental temperature.

High Output VRS sensors are designed for use in applications where higher output voltages are needed. They perform best at low to medium speeds with medium to high impedance loads. Front-End Sealed versions are available for use where the sensor is exposed to fluids, lubricants or adverse environmental conditions. Passive VRS (Variable Reluctance Speed) Magnetic Speed sensors are simple, rugged devices that do not require an external voltage source for operation. A permanent magnet in the sensor establishes a fixed magnetic field. The approach and passing of a ferrous metal target near the sensor's pole piece (sensing area) changes the flux lines of the magnetic field, dynamically changing its strength. This change in magnetic field strength induces a current into a coil winding which is attached to the output terminals. The output signal of a VRS sensor is an ac voltage that varies in amplitude and wave frequency as the speed of the monitored device changes, and is usually expressed in peak to peak voltage (

The KJT-EV58S40-LY series Variable Reluctance Speed (VRS) sensors consist of an iron core, an inductive coil and a permanent magnet and an amplifier. A ferrous pole wheel passing the sensor face changes the magnetic field strength, resulting in an AC Voltage being induced in the coil. The signal is converted to a square wave signal with constant amplitude by the integrated amplifier. The frequency of the output signal is proportional to the speed of the moving target.