Alarm device

Claim 2

An electronic alarm circuit to indicate intrusion into a protected area comprising: an alarm device, control means comprising a transistor and a biasing circuit connected to the alarm device to control operation thereof, actuating means connected to the control means actuated in response to an intrusion into the protected area to cause the control means to complete the electrical circuit of the alarm device and cause actuation thereof, and, interrupter means comprising the series combination of a relay winding and a capacitor interposed between the transistor output circuit of the control means and the alarm device to periodically interrupt actuation of the alarm device tO provide intermittent operation thereof in response to an intrusion into the protected area, the control means having timing means to cause the alarm device to remain actuated for a predetermined period of time after the actuating means are deactuated.

Claim 3

The electronic alarm circuit recited in claim 1 wherein the biasing circuit reverse biases the transistor when the actuating means are deactuated.

Claim 4

The electronic alarm circuit recited in claim 2 wherein the biasing circuit forward biases the transistor when the actuating means are actuated.

Claim 5

The electronic alarm circuit recited in claim 3 wherein the interrupter circuit is connected to the output circuit of the transistor and comprises means to selectively vary the current in said output circuit to cause intermittent operation of the alarm device.

Claim 6

The electronic alarm circuit recited in claim 3 wherein the biasing circuit comprises the series connection of resistance means and capacitance means connected through the control electrodes of the transistor to a source of potential the capacitance means being charged to maintain the transistor in reverse bias condition when the actuating means are deactuated, and the actuating means comprise means to discharge the capacitor when actuated to forward bias the transistor.

Claim 7

The electronic alarm circuit recited in claim 4 wherein the biasing circuit comprises the series connection of resistance means and capacitance means connected through the control electrodes of the transistor to a source of potential, the capacitance means being charged to maintain the transistor in reverse bias condition when the actuating means are deactuated, and the actuating means comprises means to discharge to capacitor when actuated to forward bias the transistor.

Claim 8

The electronic alarm circuit recited in claim 6 wherein the alarm device comprises an automobile horn, the protected area being the associated automobile, and wherein the actuating mean are actuated in response to the opening of an access to the automobile.

Claim 9

An electronic alarm circuit to indicate intrusion into a protected area comprising: an alarm device, control means comprising a transistor and a biasing circuit, said biasing circuit comprising a series connection of resistance means and capacitance means connected through the control electrodes of the transistor to a source of potential, actuating mean connected to said control means comprising means to discharge the capacitance means when actuated to forward bias the transistor in response to an intrusion into the protected area, thereby causing the control means to complete the electrical circuit of the alarm device and cause actuation thereof, and interrupter means interposed between the control means and the alarm device to periodically interrupt actuation of the alarm device to provide intermittent operation thereof in response to an intrusion into the protected area comprising the series connection of a relay winding being responsive to the flow of current of predetermined amplitude therethrough to actuate the alarm device, the control means having timing means to cause the alarm device to remain actuated for a predetermined period of time after the actuating means are deactuated.

Claim 10

An electronic alarm circuit to indicate intrusion into a protected area comprising: an alarm device, control means comprising a transistor and a biasing circuit, said biasing circuit comprising a series connection of resistance means and capacitance means connected through the control electrodes of the transistor to a source of potential, actuating mean connected to said control means comprising means to discharge the capacitance means when actuated to forward bias the transistor in response to an intrusion into the protected area, thereby causing the control means to complete the electrical circuit of the alarm device and cause actuation thereof, and interrupter means interposed between the control means and the alarm device to periodically interrupt actuation of the alarm device to provide intermittent operation thereof in response to an intrusion into the protected area comprising the series connection of a relay winding being responsive to the flow of current of predetermined amplitude therethrough to actuate the alarm device, the control means having timing means to cause the alarm device to remain actuated for a predetermined period of time after the actuating means are deactuated.

Claim 11

The electronic alarm circuit recited in claim 8 wherein the alarm device comprises an automobile horn, the protected area being the associated automobile, and wherein the actuating means are actuated in response to the opening of an access to the automobile.

Claim 12

The electronic alarm circuit recited in claim 8 wherein the actuating means comprises at least one switch connected in parallel with the capacitance means.