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US 4,215,351 AGranted
Chart recorders
AssigneeNational Research Development Corporation
InventorDavid J. Lowe
Life of this patent
Estimating the term…
Abstract
In a potentiometric chart recorder, the speed of the chart motor 22 is, in one mode of operation (AUTO) selected by a switch 32, varied between two values in dependence upon the rate of change or slope of the input signal at 10 as detected in a detector 30. The slow speed is obtained by intermittent operation at the fast speed, and during the non-operative periods power-consuming circuitry e.g. 16, 18, 26 is switched off by a switch 40.
Claims17
A chart recorder, comprising:
- an input terminal for receiving an electrical input signal a value of which is to be recorded;
- first drive means for relatively moving a length of record medium past a recording member at a selectable controlled rate;
- and
- second drive means connected to said input terminal for relatively moving the recording member across the record medium to a position dependent upon the said value of said input signal;
- wherein the improvement comprises means which at least in one mode of operation of the recorder connects said first drive means to said input terminal such that said first drive means is responsive to said input signal, for making said rate, at which the record medium is relatively moved past the recording member, automatically dependent upon the slope of said input signal.
2 more elements
A chart recorder, comprising:
- an input terminal for receiving an electrical input signal a value of which is to be recorded;
- first drive means including circuitry and for relatively moving a length of record medium past a recording member at a selectable controlled rate;
- and
- second drive means including circuitry and connected to said input terminal for relatively moving the recording member across the record medium to a position dependent upon the value of said input signal;
- means for selectively operating the first drive means at a fast speed or a slow speed and obtaining the slow speed by intermittent operation at the fast speed, and means responsive to selection of the slow-speed condition for disconnecting, during the non-operative periods, at least some of said circuitry from its power supply, whereby power consumption is reduced.
2 more elements
Dependencies are inferred from the claim text.