Bed egress alarm circuit

Claim 1

A condition responsive circuit for signalling the departure of a patient from a bed or the like by generating an output signal upon the opening of a switch, comprising: a switch being normally closed by the weight of a patient in a bed; an FET having source, drain and gate electrodes, said gate electrode connected to said switch for normally drawing only a nominal current and for continuously biasing said gate electrode to render said FET non-conductive; a normally off output means coupled to said at least one of source and drain electrodes for generating an output signal when said FET is rendered conductive; the opening of said switch to remove the continuous bias from said gate electrode; delay means coupled to said switch and said gate electrode for maintaining a bias at said gate electrode to prevent said FET from being rendered conductive for a predetermined time interval after the opening of said switch; and said output means including an SCR, an SCR switch, and a signal means, all connected in series; said SCR being rendered conductive by said FET being renderEd conductive to thereby generate an output signal from said signal means, and said SCR being thereafter rendered nonconductive only by operating said SCR switch.