Device for finding concealed studs
First Claim
1. A device for detecting the position of a stud in a partition comprising first and second substantially coplanar side-by-side capacitor plates which are electrically isolated from one another, means for applying an alternating signal to said plates through first and second impedance means respectively, so as to produce on said plates alternating voltage signals of amplitude related to the capacitance of each plate, means for producing a first electrical signal related to the sum of such alternating voltage signals, means for producing a second electrical signal related to the difference between such alternating voltage signals and display means including display enabling means operable in accordance with said first electrical signal and balance indicating means operable in accordance with said second electrical signal.
2 Assignments
0 Petitions
Accused Products
Abstract
A detector device for finding concealed studs in partitioning includes a pair of plates which are supplied with ac via resistors. Amplifiers produce outputs representing the sum and difference respectively of the signals imposed on the plates. The sum signal drives a display enabling circuit including a comparator which enables a display means to operate when the sum signal exceeds a threshold level. The difference signal drives two comparators which control three display device such that one display device is operated only when the detector device is over the center of a stud. The other display devices indicate which way the detector should be moved to place it over the center of the stud.
51 Citations
13 Claims
- 1. A device for detecting the position of a stud in a partition comprising first and second substantially coplanar side-by-side capacitor plates which are electrically isolated from one another, means for applying an alternating signal to said plates through first and second impedance means respectively, so as to produce on said plates alternating voltage signals of amplitude related to the capacitance of each plate, means for producing a first electrical signal related to the sum of such alternating voltage signals, means for producing a second electrical signal related to the difference between such alternating voltage signals and display means including display enabling means operable in accordance with said first electrical signal and balance indicating means operable in accordance with said second electrical signal.
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13. A device for detecting the position of a stud in a partition comprising first and second substantially coplanar side-by-side capacitor plates which are electrically isolated from one another, an oscillator for applying an alternating signal to said plates through first and second resistors respectively, so as to produce on said plates alternating voltage signals of amplitude related to the capacitance of each circuit plate, a summing circuit for producing a first electrical signal related to the sum of such alternating voltage signals, a difference circuit for producing a second electrical signal related to the difference between such alternating voltage signals and a display including a display enabling circuit operable in accordance with said first electrical signal and a balance indicator operable in accordance with said second electrical signal.
Specification