JPS5821508A - Potentiometer - Google Patents

Abstract

PURPOSE:To attain a long life and high accuracy witout sliding, by using a shift register constituted by connecting a plurality of bit elements in series. CONSTITUTION:A high level signal from a high level signal source 3 is inputted by the first shot of pulses Pc from a clock source 1. The bit element 4-1 of the shift register 4 memorizes said signal. The memory bit of the high level signal is shifted to the right at evercy clock pulse Pc which is sequentially generated. When the bit corresponding to the position of a sensor 6 becomes a high level, the output of the sensor stops a counter 5 which has counted the clocks. Since the counted value is proportional to the sensor position, the digital value itself is oututted or it is converted into an analog value and outputted as a voltage. A numeral 2 in the Figure is a reset pulse source.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a potentiometer, particularly a potentiometer without a sliding mechanism.

Potentiometers have been commonly used in various measuring instruments and instruments. For example, in automatic balance recorders, potentiometers are used to detect the position of the ben and convert it into an electrical signal. However, conventional potentiometers have a sliding mechanism that constantly rotates, so the sliding winding that comes into contact with the slide wears out, resulting in a short service life.

The present invention aims to eliminate the drawbacks of the conventional potentiometers described above and provide a non-sliding potentiometer with a long life and high precision. It is characterized by the use of a shift register consisting of bit elements connected in series.

The present invention will be described in detail below with reference to an embodiment shown in one drawing.

FIG. 1 is a circuit block diagram of a potentiometer showing an embodiment of the present invention.

In FIG. 1, 1 is a clock bus p generator, 2 is a reset bus p generator, 3 is a high level signal generation source, and 4 is n bit elements 4-1@4-2...4- n is a shift register configured by connecting them in series, 5 is a counter,
6 is a sensor. Although not shown, the sensor 6 moves together with the position moving body.

Each bit element of the shift register 4 is still arranged along the moving path of the moving object. The clock pulse Pc generated by the clock pulse generator 1 is used as a shift pulse for each bit element 4-1, 4-2, etc. of the shift register 4.
・Along with being added to 4-n.

It is input to counter 5. Further, the reset pulse Pr generated by the reset pulse generator 2 is also sent to the shift register 4.
are connected to each bit element 4-1, 4-2, . . . 4-n.

Now, when the circuit shown in FIG. 1 starts operating, the clock pulse of the first note from the clock pulse generator 1 causes
The bit element 4-1 receives the high level signal from the high level signal generation source 6 at its input and stores it. When a subsequent clock pulse is applied, the high level signal stored in bit element 4-1 is shifted to bit element 4-2 and stored. Ru. Similarly, each time a clock pulse is generated and applied, the storage bit of the high level signal in the shift register 4 is shifted, and when the high level signal reaches the bit element corresponding to the position of the sensor 6, the sensor 6 is Detects high level signals. On the other hand, since the counter 5 counts clock pulses after the start of the shift operation, when the high-level signal is shifted to the bit element corresponding to the sensor 6, the count contents of the counter 5 also become the corresponding value. ing. Therefore, when the sensor 6 detects that a high level signal has been shifted to the corresponding bit element, the counter 5 stops counting based on the detection output. Since the count value of the counter 5 when stopped is proportional to the position of the sensor 6, this digital image symbol may be directly derived as a position signal, or it may be further converted to an analog signal by a DA converter, or the sensor of the potentiometer may be used. (Moving object) It is possible to obtain electric current and voltage proportional to the position.

FIG. 2 shows a more specific example of the sensor 6 portion in FIG. 1. In the figure, reference numeral 7 denotes a light source using a light emitting diode, which is connected to the position detection shaft 10 of the potentiometer. Reference numeral 8 denotes an element whose resistance value changes according to light, which is made of, for example, cadmium sulfide, and is connected to the conductor 9. Assuming that the position detection axis 10 is now at the position of the bit element 4-4 and a high level signal has been shifted to the bit element 4-4, the resistance of the light guide 8 is lowered by the light from the light source 7, and the bit element is The high level output of 4-4 is output from light guide 8. It is applied to the counter 5 via the conductor 9 and stops the counting operation.

Note that when the reset pulse Pr is applied, each bit element of the shift register 4 is cleared. Reset pulse Pr
As shown in FIG. 6, the clock pulse Pc is also generated at regular intervals, and when the reset pulse Pr is generated, the clock pulse Pc also starts in synchronization with this. That is, the reset pulse P
The measured value is updated at a period of r. If a continuous analog signal is required, the DA-converted signal may be held until the output point of the next cycle.

Further, in the above embodiment, the clock counting of the counter is stopped at the sensor output, but the counting contents may be read out at the time of the sensor output without stopping the counting.

In addition, while we used optical sensors as an example, there are also sensors that use electrostatic or electromagnetic coupling.

Other non-contact types may also be used.

Furthermore, the moving direction of the moving body of the potentiometer can be freely adapted to either a rotary type or a linear type.

The potentiometer of this invention is as described above.

a shift register in which a plurality of bit elements each arranged along a movement path of a position moving body are connected in series; a means for inputting a predetermined signal to shift a reference bit element of the shift register; means for counting the shift status at the start of the shift; means for detecting when the signal shift of the shift register reaches the position of the moving object; and means for deriving the output of the counting means as a position signal in accordance with the output of the detection means. Since it is made of Toyoshi, there are no contact parts, so you can get a product with a long lifespan.

In addition, since it is mainly composed of shift registers, it is possible to use ultra-LSI, which has improved greatly in terms of integration quality in recent years, and it is also possible to reduce the size and cost. In addition, the linearity is better compared to the conventional sliding coil.
Since it also has excellent temperature characteristics, it is possible to obtain a highly accurate potentiometer.

[Brief explanation of drawings]

FIG. 1 is a circuit block diagram of a potentiometer showing an embodiment of the present invention, FIG. 2 is a diagram showing a more specific example of the sensor portion shown in FIG. 1, and FIG. 3 is a diagram showing a reset pulse and a clock pulse. It is a figure showing a relationship. 1; Clock pulse generator, 2I reset pulse generator, '3; High level signal source. 4N shift register, 5; counter. 6N sensor, 7; light source, 8N light guide. 9; Conductor; 10; Position detection axis. Patent applicant Shimadzu Corporation Representative Patent attorney Shigeru Nakamura

Claims (1)

[Claims] A shift register in which a plurality of bit elements are connected in series, each of which is arranged along the movement path of the position moving body and the one position moving body, and a reference bit element of this shift register is shifted by inputting a predetermined signal. means for counting the shift status at the start of said shift; means for detecting when the signal shift of said shift register reaches the position of said moving object; and said counting means output in accordance with the output of said detection means. A constant tension V yometer, characterized in that it is provided with means for deriving the position signal as a position signal.