Prealarm system for an anti-theft alarm

• US 5,216,407 A
• Filed: 03/10/1992
• Issued: 06/01/1993
• Est. Priority Date: 03/10/1992
• Status: Expired due to Term

• Current Assignee: Shih-Ming Hwang
• Original Assignee: Shih-Ming Hwang
• Inventors: Hwang, Shih-Ming
• Primary Examiner(s): Swann, III, Glen R.
• Application Number:
  US07/848,199
• Time in Patent Office: 448 Days
• Field of Search: 340/426, 340/429
• US Class Current: 340/426.22
• CPC Class Codes: B60R 25/104 characterised by the type of theft warning signal, e.g. visual or audible signals with special characteristics

Abstract

A prealarm system is provided for an anti-theft alarm where a signal from a displacement/vibration detector is picked up by a one-shot timer circuit. If no other activation signal is picked up after the first signal is received a main control alarm circuit is activated for (1) driving a siren circuit to generate a short chirp sound as an audible warning, and (2) a flashing circuit to flash a light for a preset period of time as a visible warning. If the number of activation signals received subsequent to the first are greater than a predetermined threshold number, or the activation signal continues for a predetermined period of time, the main control alarm circuit is activated for driving, (1) the siren circuit to give a normal audible signal alarm, and (2) both, the flashing circuit for flashing a light and the dome light control to provide visible signals.

Claims

1. A prealarm system for coupling to an anti-theft alarm system, comprising:

sensor means for generating at least one activation signal responsive to detection of an attempted entry into a vehicle;

one-shot timer means coupled to said sensor means for generating a first control signal responsive to said activation signal;

alarm control means coupled to said one-shot timer means for (1) generating a second control signal responsive to fewer than a predetermined number of occurrences of said first control signal in a selected time, or (2) generating a third control signal responsive to a predetermined number of occurrences of said first control signal in said selected time;

alarm means coupled to said alarm control means for generating an audible warning tone signal responsive to said second control signal and an audible alarm signal responsive to said third control signal;

light flashing means coupled to said alarm control means for flashing a light for a predetermined time period responsive to said second control signal and substantially continuously flashing said light responsive to said third control signal;

dome light control means coupled to said alarm control means for illuminating a vehicle dome light responsive to said third control signal; and

,

paging signal means coupled to said alarm control means for transmitting a warning signal to a remote communication system responsive to said third control signal.

2. A prealarm system for coupling to an anti-theft alarm system, comprising:

sensor means for generating at least one activation signal responsive to detection of an attempted entry into a protected space;

one-shot timer means coupled to said sensor means for generating a first control signal responsive to said activation signal;

alarm control means coupled to said one-shot timer means for generating a second control signal responsive to a predetermined number of occurrences of said first control signal in a selected time;

alarm means coupled to said one shot timer means for generating an audible warning tone signal responsive to said first control signal, said alarm means being further coupled to said alarm control means for generating an audible alarm signal responsive to said second control signal;

light flashing means coupled to said one-shot timer means for flashing a light for a predetermined time period responsive to said first control signal, said light flashing means being coupled to said alarm control means for substantially continuously flashing said light responsive to said second control signal; and

a sensitivity indicator coupled intermediate said sensor means and said one-shot timer means for indicating the presence of said activation signal, whereby said sensitivity indicator facilitates sensitivity adjustment of said sensor means by providing a visual indication of an output from said sensor means.