Fluid level limit value electrical transducer - has Wiegand wire attached to float with excitation and sensing coils

摘要

A limit value transducer for fluids is esp. applicable as an oil or fuel level indicator and uses a float (14) borne by the fluid (15). It is a compact, simple, economically produced electrical transducer with a low internal impedance. A Wiegand wire (13) is attached to the float (14) and passes through a non-magnetisable tube (10) of glass carrying one or pref. two coils (11,12). One coil carries an a.c. of frequency 400 Hz at the most. One coil (11) is a read-out coil of thin wire. The other coil is a thicker stimulating coil (12) wound around the sensing coil (11). Several sensing coils may be used with a common excitation coil. Alternatively, separate sensing and excitation coil pairs are used for upper and lower fluid limits.