Sleep sensing apparatus for use on automotive vehicles

Claim 1

Apparatus for providing a warning when the driver of a motor vehicle becomes drowsy or falls asleep while driving, comprising: A. an electrical switch coupled to steering apparatus of a motor vehicle or the like, said switch being of the single pole double throw type, the coupling to said steering apparatus being such that a small movement of the steering apparatus moves the pole of the switch from one throw to the other, the single pole of said switch being grounded, B. an alarm circuit including an alarm device connected in series with a silicon controlled rectifier and adapted to be connected across the terminals of a suitably regulated direct current source, the negative terminal being grounded, a series connected capacitor and resistance being coupled between the positive terminal of said direct current source and the junction between said alarm and rectifier; C. a programmable unijunction switch, said switch having a programming element coupled to a voltage dividing network effectively coupled across said alarm circuit, the base of the unijunction switch being grounded through a resistance element and being directly coupled to the gate of said silicon controlled rectifier and the other element of said unijunction switch being coupled through a resistance across said direct current source, through a variable resistance to the positive terminal of a grounded direct current generator, a capacitordiode network for supplying a negative potential through a resistance element, one throw of said switch being coupled to said capacitor-diode network and to the positive side of said direct current source and the other throw of said switch being coupled to the junction between the series connected capacitor and resistance which are connected between the positive terminal of said direct current source and the junction between said alarm and said rectifier.