US 3,962,620 A · Switching apparatus

Abstract

A programmer or switching apparatus produces an ON and OFF valued control signal for turning an associated controlled component ON and OFF at preselected points in the variation range of a reference variable. The apparatus includes a reference transducer for converting the reference variable into a reference signal representing the variable. A pair of set-point devices provide a pair of set-point signals which are compared with the reference signal to define operating points at which the control signal switches between its ON and OFF values. The apparatus has the versatility of allowing, by merely setting the set-point devices and without making any circuit changes, the first transition of the control signal to be either from ON to OFF or from OFF to ON as the reference variable increases from its minimum to its maximum value. A number of basic units or parts of basic units may be combined to provide a number of control channels controlling the operation of a number of controlled components in response to the same reference variable. The reference variable may be the angular displacement of a rotatable shaft which may rotate continuously in one direction through repeated revolutions or which may oscillate back and forth between given end points. It may also be the linear displacement of a linearly movable element, or it may be some other continuously variable quantity such as elapsed time, temperature, pressure, liquid level, etc.

Claims9

Dependent claims

A switching apparatus for producing an ON and OFF valued control signal which switches from one value to the other at adjustable selected points in the variation range of a given reference variable, said switching apparatus comprising:

a reference transducer having said reference variable as an input thereto and operable to convert said reference variable to a reference signal the magnitude of which reference signal corresponds to the magnitude of said reference variable, an ON set-point device for producing an ON set-point signal having a selectively variable magnitude, an OFF set-point device for producing an OFF set-point signal having a selectively variable magnitude which may be either higher or lower than the magnitude of said ON set-point signal, and a control signal generating means responsive to said reference signal, to said ON set-point signal and to said OFF set-point signal for generating an ON and OFF valued control signal which, as said reference signal increases in magnitude and regardless of whether said ON set-point signal is of a higher or lower magnitude than said OFF set-point signal, switches from its OFF to its ON value when said reference signal reaches comparison with said ON set-point signal and which switches from its ON to its OFF value when said reference signal reaches comparison with said OFF set-point signal.

A switching apparatus responsive to a given reference variable and comprising:

a reference transducer having said reference variable as an input thereto and operable to convert said reference variable to a reference signal the magnitude of which reference signal corresponds to the magnitude of said reference variable, an ON set-point device for producing an ON set-point signal of selectively variable magnitude, an OFF set-point device for producing an OFF set-point signal of selectively variable magnitude, an ON comparator for comparing said ON set-point signal with said reference signal, an OFF comparator for comparing said OFF set-point signal with said reference signal, a third comparator for comparing said ON set-point signal with said OFF set-point signal, and a logic device responsive to the outputs of said three comparators for providing an ON and OFF valued control signal which, for an increasing reference variable, goes ON when said reference signal reaches comparison with said ON set-point signal and goes OFF when said reference signal reaches comparison with said OFF set-point signal regardless of whether said ON set-point signal is of a higher or lower magnitude than that of said OFF set-point signal.

Dependencies are inferred from the claim text.

Switching apparatus

Life of this patent

Switching apparatus

Life of this patent

Abstract

Claims9