US 6,642,848 B1 · Shock sensor by variable capacitor

Abstract

This invention is pertaining to multi purpose shock sensor comprising three conductive plates arranged in 3 layers in parallel which make 2 variable capacitors connected in series. Two outer plates are firmly attached to a supporting insulating material and the center plate is located between the 2 outer plates and arranged as movable by resilient element toward either side of the outer plate depending on the direction of the impact felt on the shock sensor causing changes of the capacitance values of the both capacitors. If the 2 capacitors are connected across a voltage source through a resistor, the voltage is charged across the 2 capacitors and their charged values are inversely proportional to their capacitance values. Moving the center plate due to a shock causes changes on both capacitance values, which change voltages across the capacitors, and the changed voltage can be used to activate an object. The shock sensor can be used for door alarm, auto alarm, hard disk drive sensor, automobile impact sensor and other applications.

Claims5

Dependent claims

A shock sensor comprising:

three metal conductive plates, of which two metal conductive outer plates affixed firmly to insulator support means, separated with some distances by a movable metal conductive center plate affixed to said support means through an elastic means, wherein the three plates comprising two variable capacitors connected in series;
a voltage source to supply charging voltage across each capacitor, wherein the voltage across each capacitor detects the changed capacitance in response to shock, or impact felt on the center plate;
a resistor connected in series with said two variable capacitors across the voltage source to limit the charging current;
insulating support means to which the conductive plates affixed, wherein if the center plate vibrates caused by a shock sensed on the plate, the capacitance values of said two variable capacitors are changed, in response to shock or impact applied on the plate, in turn, changing the voltage drop across each capacitor, the changed voltage is inversely proportional to the capacitance value.

1 more element

Dependencies are inferred from the claim text.

Shock sensor by variable capacitor

Life of this patent

Shock sensor by variable capacitor

Life of this patent

Abstract

Claims5