| 摘要 |
An electronic digital slide rule in the form of a small hand-carried, battery powered digital electronic calculator capable of performing substantially all of the mathematical operations performed by the conventional mechanical slide rule. The electronic digital slide rule utilizes a computing technique based on integrating for a period of time proportional to one input variable x, a fixed or variable pulse rate signal, the magnitude of which may be proportional to another input variable y, to a constant, or to some other known function. The computing technique is implemented by a pulse rate generator producing a pulsetrain representative of one factor of a function whose solution is desired. First factor input means are provided for supplying the one factor to the input of the pulse rate generation means whose output is supplied to an output integrator and timing circuit. A second factor input means is coupled to and controls at least in part operation of the output integrator and timing circuit means. The electronic digital slide rule is completed by a function selector switching means that interconnects the pulse rate generation means to the second factor input means and to the output integrator and timing circuit means in a manner to perform a selected one of a plurality of different logical operations on the first and second input factors to thereby derive a desired output solution. In preferred embodiments of the slide rule, an output indicating means is coupled to the output from the output integrator and timing circuit means for displaying the solution in legible form. The plurality of different logical operations capable of being performed by the electronic digital slide rule include the arithmetic operations of addition, subtraction, multiplication, division, squaring and square rooting, and exponential, logarithmic and trigonometric operations. In constructing the electronic digital slide rule, the first and second factor input means may comprise mechanical switches having a plurality of discrete contact positions which also serve as in input memory for retaining the value of the input first and/or second factors. It is also preferred that the electronic digital slide rule operate from a battery operated power supply means for supplying energizing power to the slide rule through a start-stop switch which energizes the slide rule only during periods of use and conserves the battery power supply during periods of non-use. It is also anticipated that the electronic digital slide rule would be fabricated from micro-miniaturized integrated circuit structures mounted on a single supporting circuit board and housed in the form of a pocket size container for easy transport and use. A preferred embodiment of the electronic digital slide rule also includes a decimal point placement indicating means for visibly indicating to the user of the device the position of the decimal point in an output solution displayed by the output indicating means.
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