Composite automatic control system for vehicle engine with theft prevention circuit

Claim 1

A composite automatic control system for theft prevention of a vehicle comprising a secret coded locking circuit including: (a) A plurality of manually operated switches; (b) first pulse generating circuit means connected to said plurality of switches whereby one pulse is generated at the output of the first pulse generating circuit means each time when any one of the switches is operated; (c) counter means connected to the output of the first pulse generating circuit means to count the number of the output pulses whereby an output of logic HIGH signal is provided each time when a count of predetermined number of pulses is reached; (d) timing circuit means and second pulse generating circuit means connected to a predetermined number of switches preselected from said plurality of switches whereby the second pulse generating circuit means provides an output of logic HIGH signal to enable an electrically controlled device to be operated with DC power only if said predetermined number of preselected switches are operated in a predetermined sequence within a predetermined time interval, the number of preselected switches being equal to said predetermined number of pulses; and (e) judging circuit means connected to the output of said counter means and to the output of said second pulse generating circuit means whereby the judging circuit means provides an output of logic HIGH signal to enable an alarm device to be operated with DC power and at the same time disable the electrically control device unless the output of said counter means and the output of said second pulse generating means are both of logic HIGH signal.