Automatic range selector

Claim 1

In a meter mechanism for indicating the value of an unknown parameter applied thereto, the mechanism including a scale with a plurality of ranges of values to which the meter mechanism can be made responsive at a particular instant, a range selector for developing an indication of the particular range of the scale which encompasses the value of the unknown parameter, and a scale selector coupled to the scale and the range selector and being responsive to the indication of the range selector to select the particular range of the scale and to make the meter mechanism responsive thereto, the improvement in the range selector, comprising: a meter relay coupled to said meter mechanism and being responsive to the value of the unknown parameter being outside the range to which the meter mechanism is then responsive to develop a high signal with the value of the unknown parameter of greater value and a low signal with the value of the unknown parameter of lesser value, and a plurality of stepping relays coupled in series to form a cascaded series of N relays, where N is an integer, said cascaded series being arranged in sequence from the first through the Nth relay, each of said N relays having a rotating portion with a number of contact positions, each combination of positions of all of the rotating portions of said stepping relays having associated therewith one of said ranges so that rotation of said rotating portion of any of said relays from one contact position to an adjacent contact position in one direction corresponds to ranges of increasing value and in the other direction corresponds to ranges of decreasing value, one of the contact positions of the first through said (N-1)th relays being a transfer position and said relays being so coupled to each other that with rotation of one of said rotating portions to the transfer position thereof in said one direction causes the rotating portion of the adjacent relay next higher in order in the order from said first through Nth relay to rotate to the next contact position thereof in said one direction and with rotation of one of said rotating portions to the transfer position thereof in said other direction causes the rotating portion of the adjacent relay next lower in order in the order from said first through Nth relay to rotate to the next contact position thereof in said other direction, a relay of said cascaded series being coupled to said meter relay and the scale selector and being responsive to said high signal to rotate the rotating portion thereof in said one direction to the next adjacent contact position and being responsive to said low signal to rotate the rotating portion in said other direction to the next adjacent contact position, the scale selector being responsive to the contact position of said rotating portion to make the meter mechanism responsive to the range associated with the combination of contact positions of said rotating portions.