US 4,057,791 A · Motion responsive alarm system

Abstract

The alarm system, which may be fastened to an object whose movement is to be monitored, includes a unique sensor array providing no output in any static orientation and a pulsating output in response to motional disturbances. A latch circuit is connected to the sensor array and develops a logically high output in response to a pulse from the sensor array. The output of the latch circuit remains logically high until the sensor array fails to output a pulse for a first predetermined time. A triggering circuit generates a trigger signal for activating a series of alarm functions after the latch circuit output has been continuously logically high for a number of the first predetermined time periods. Also, an alarm function may be connected to the latch circuit so as to activate whenever the latch output is logically high.

Claims10

Dependent claims

In an alarm system of the type for responding to motion, the improved combination comprising:

a. sensing means for detecting a motional disturbance and producing a pulsating signal in response thereto;
b. latch means connected for receiving said signal from said sensing means and having an output normally at a first logical level, said output of said latch means transitioning to a second logical level in response to the first pulse of said signal and remaining at said second logical level until said sensing means is characterized by the absence of said signal for a first predetermined time;
c. trigger means responsive to said output of said latch means for developing a trigger signal only after said output of said latch means has continuously been at said second logical level for a second predetermined time;
d. alarm means connected to said trigger means for generating an alarm signal in response to said trigger signal;
and
e. a source of potential.

3 more elements

Dependencies are inferred from the claim text.

Motion responsive alarm system

Life of this patent

Motion responsive alarm system

Life of this patent

Abstract

Claims10