Stud sensor with digital averager and dual sensitivity
AssigneeZircon Corporation
InventorCharles E. Heger
Life of this patent
Estimating the term…
Abstract
A dual sensitivity stud sensor senses studs through both thick and thin surfaces. Studs are sensed by detecting a change in the capacitive loading of plates as they are moved along a surface and into proximity with a stud. The sensor informs the operator when the sensor has (incorrectly) been calibrated over a stud. The sensor also informs the operator if the sensor is placed against a surface either too thick or too thin for stud detection. Through use of a digital register, the sensor remains calibrated indefinitely while the sensor is powered on.
Claims21
A portable device for locating a stud positioned behind a surface comprising:
- a sensor sensing additional capacitive loading caused by the stud while said sensor moves along the surface approaching the stud and providing digital data signals as output when said additional capacitive loading is sensed;
- a digital averager receiving the data signals from said sensor and averaging them;
- and
- a display processor receiving the averaged data and in response providing an indication of the stud position on a display unit.
A method for locating a stud positioned behind a surface comprising the steps of:
- providing a sensor;
- sensing additional capacitive loading caused by the stud while said sensor moves along the surface approaching the stud;
- sending digital data signals from said sensor when said additional capacitive loading is sensed;
- averaging said data signals digitally over a predetermined time period;
- and
- displaying said data signals.
A portable device for locating a stud positioned behind a surface comprising:
- sensor circuitry including a differential capacitive plate circuit, sensing unbalanced capacitive loading of two plates in the differential capacitive plate circuit, and providing digital data signals when unbalanced capacitive loading of the two plates is sensed;
- and
- a display processor receiving said digital data signals and in response providing an indication of the stud position on a display, said display processor providing a linearly stepped voltage to said differential capacitive plate circuit as an offset voltage to cause the sensor circuitry to a null state.
Dependencies are inferred from the claim text.