Surface mount rotary position sensors maximise precision at 1% linearity

February 20, 2015 // By Graham Prophet
Murata has announced what it claims to be the most precise surface-mount type rotary position sensors available, the compact and low-profile SVK3 series. With linearity of ±1%, the sensors achieve twice the precision of the preceding products and withstand the automotive temperature range.

Rotary position sensors are used as feedback control devices for drive motors and as temperature and airflow adjustment switches in vehicle air conditioning systems, to detect the rotation state (angle) of motors or switches. Market demand is growing for more finely tuned motor control and switch adjustment; Murata has developed the SVK3 series, rotary position sensors that achieve a level of control precision it says has previously difficult to attain, for example fine enough to enable subtle adjustments to the visibility of head-up display (HUD) screens, or fine temperature adjustment settings to fractional values beyond the decimal point using air conditioner temperature adjustment switches. The devices measure W11 × L12 × T2.1 mm and weigh 0.4g; they can gbe used as direct upgrades for earlier Murata parts.

The sensors meet the usable temperature range (-40 to 125 degrees C) and service life (300,000 cycles) requirements for automotive applications. The SVK3 series rotary sensors have a resistance of 10 kΩ, and provide an effective angle of rotary movement of 333.3 degrees.

Specific examples of applications for the versatile SVK3 series include electronic rotary switches for automobile air conditioning (climate control) systems, visibility adjustment, position memory, failsafe functions for head-up display (HUD) screens, electronic rotary switches, selectors for household appliances (washing machines, coffee makers, etc.), and as feedback sensors for motor drive devices in robots.