Alert alarm responsive to an unaccompanied child

An alarm permissive of the passage through a portal of an adult, and of the passage of a child preceded or followed by an adult within preselected lengths of time, and responsive to the passage of a child unless preceded by or followed by an adult dimension of height, a dimension of width, and a pair of spaced apart sides, said alarm comprising:

• an adult sensor disposed at an upper height at one side of said portal;
• a child sensor disposed at a lower height at one side of said portal;
• an energy beam directed across said portal from side to side at each of said heights, directed at the respective one of said sensors whereby each said sensor is responsive to a physical presence in said portal at its respective height;
• adult actuator circuitry adapted to be triggered by a signal from said adult sensor respective to a physical presence in the portal at said adult height, said adult actuator circuitry including an adult timer which defines a length of time a child may pass through the portal after an adult has passed without giving an alarm;
• child actuator circuitry adapted to be triggered by a signal from said child sensor respective to a physical presence at said child height, said child actuator circuitry including a child timer which defines a length of time within which an adult must pass through the portal after a child has passed without giving an alarm;
• and
• alarm circuitry responsive to said actuator circuitry to announce the occasion when said child actuator circuitry has been triggered without a preceding or subsequent triggering of said adult actuator circuitry within lengths of time respective to the first of the actuator circuitry to be triggered.