Automatic time-controlled alarm system

Claim 1

A self powered alarm system which provides for a predetermined time period during which a false alarm may be corrected, comprising: a. electrical sensor means for sensing an alarm condition; b. electrically actuated first alarm signal means for generating a first audible alarm signal; c. first electronic alarm switching means switchably connecting said sensor means and said first alarm signal means for energizing said first alarm signal means immediately upon tripping of said sensor means; d. first electronic time delay means, connected to and triggered by said first alarm switching means, for measuring a first time delay following energization of said first alarm signal means; e. electrically actuated second alarm signal means for producing a second alarm signal; f. second alarm signal interrupt means for periodically interrupting said second alarm signal means for driving said second alarm signal means, and having a transistor with its input in parallel with a capacitor and its output connected to a relay, the transistor and relay cooperating to cause the capacitor to alternately charge and discharge, producing an alternating signal which drives said second alarm signal means, said second alarm signal interrupt means being connected in series with said second alarm signal means so that electrical current through said second alarm signal means operates said second alarm signal interrupt means; g. second electronic time delay means for measuring a second time delay, said second time delay commencing at the termination of said first time delay; h. automatic reset means connected to and driven by said second time delay means for de-energizing and re-setting said alarm system; i. false alarm reset means for manually de-energizing and resetting said alarm system; j. power means for energizing said alarm system; and k. second electronic alarm switching means, connected to and activated by said first time delay means, for connecting said power means to said second alarm signal means and to said second time delay means when said first time delay has been measured.