JPS63151815A - Apparatus for displaying displacement quantity - Google Patents

Abstract

PURPOSE:To accurately determine the displacement level of a part to be detected, by mounting a sensor resistor, a first amplifying circuit, an output stage transistor, a display circuit, a potential follower circuit, a switch means, a timer circuit and a second amplifying circuit. CONSTITUTION:The voltage appearing at one terminal of a sensor resistor RS immediately after a key switch 2 is closed is amplified by a first amplifying circuit OP1 to be given to output stage transistors Tr10, Tr11 and directly transmitted to a display means 8 without generating the relay of display and, therefore, displacement quantity can be rapidly determined at the simultaneous point of time when the key switch 2 is closed. During this time, the condenser C1 in a displacement follower circuit 4 is rapidly charged on the basis of the signal from a timer circuit 6. After this charge is performed, the output signal of the circuit OP1 is made ineffective and the signal of a second amplifying circuit OP2 amplifying the voltage at one terminal of the condenser C1 is given to the transistors Tr10, Tr11. Then, the display means 8 is controlled on the basis of the voltage at one terminal of the condenser C1. By this method, even when a part to be detected largely displaces and a resistance value abruptly and largely varies, the indicator of the display means 8 is not abruptly shaken and easy to look at.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention has a sensor resistor whose resistance value changes depending on the displacement level of a detected portion whose amount of displacement is detected. This invention relates to a displacement display device using an ammeter type gauge that drives the pointer of the ammeter type gauge according to a value change, and uses this pointer to display the above-mentioned displacement level. It is used.

[Conventional technology]

Conventionally, in order to detect mechanical displacement, a variable resistor is operated based on the amount of displacement, and a gauge pointer is moved based on the change in the resistance value of this variable resistor to display the amount of displacement. This device is commonly used, but the problem is that when the amount of displacement changes rapidly, the pointer vibrates violently, causing discomfort to the observer who watches the movement of the pointer, and making it difficult to correctly recognize the amount of displacement. There was a point.

For example, in a display device that displays the liquid level in a vehicle's fuel tank, the liquid level may vibrate violently due to vehicle vibrations while the vehicle is running; If the pointer fluctuates significantly, it can cause discomfort to the driver of the vehicle and make it difficult to accurately determine the amount of remaining fuel. For this reason, various devices have been developed. For example, a delay circuit is provided between a sensor and a display section that displays the signal from the sensor, and the magnitude of the delay operation of this delay circuit is selectively switched. Therefore, a device has been developed that provides a large delay in activation when there is a relatively large change in the liquid level, such as when the vehicle is running, to prevent the pointer from vibrating due to sudden changes in the liquid level. For example, Japanese Utility Model Publication No. 59-37699 describes a circuit shown in FIG. 2, in which a signal from a liquid level sensor 71 is transmitted to an amplifier 73 via a delay circuit 74.
This amplifier amplifies the signal to drive an ammeter type meter 72. Then, when a signal is output from the liquid level sensor 71 in response to a signal from the key switch 2, the preset circuit 75 reduces the delay operation of the delay circuit 74 for a predetermined period of time from that time, so that the liquid level sensor is activated. The detected liquid level is quickly transmitted to the meter 72 and displayed. On the other hand, if the liquid level is relatively easy to fluctuate after a predetermined period of time has passed since the key switch 2 was turned on, the preset circuit 75 One idea is to increase the delay operation of the delay circuit 74 so that even if the liquid level changes rapidly, the meter 72 follows it and the pointer does not move suddenly.

[Problem that the invention seeks to solve]

However, this circuit basically provides a delay circuit between the liquid level sensor and the meter and switches the delay operation of this delay circuit. Therefore, even if the meter wants to display the liquid level quickly based on the signal from the liquid level sensor, it is inevitable that a certain amount of delay will occur.For example, immediately after the key switch is turned on, It was not possible to display the liquid level in the gasoline tank. In other words, even in such a case, only a circuit configuration that can perform a certain degree of delay operation could be constructed. That is, in the configuration in which the delay time of the delay circuit is switched, the charging of the capacitor in the delay circuit is switched from rapid charging to slow charging.
Even rapid charging requires a certain amount of time, and it is impossible to make the charging time extremely long because this would involve increasing the size of the circuit. Therefore, even when rapid charging is performed and the delay circuit's delay operation is small, there is a certain amount of delay in operation, making it difficult to promptly display the signal from the liquid level sensor on the meter. .

Therefore, the present invention immediately moves the pointer according to the displacement level of the detected part, and when the displacement level is desired to be displayed, it is displayed immediately without unnecessary delay operation, and as a result, the display device can be visually checked. If the displacement of the detected part changes significantly in a short period of time due to disturbance, the change can be immediately communicated to the guide. figure,
To provide a displacement amount display device that can reduce the amount of touch of a pointer and eliminate the disadvantages such as making an observer visually viewing the display device feel uncomfortable and making it difficult to accurately grasp the amount of displacement of a detected part. The purpose is to

[Structure of the invention]

In order to solve the above-mentioned problems, the present invention amplifies the voltage appearing at one end of the sensor resistor via the first amplifier circuit (OPI), and transmits this signal to the output stage transistor (T r II T
r ++), the display means connected to the collector side of the output stage transistor immediately causes the pointer to swing based on the change in the resistance value of the sensor resistor, and the amount of displacement of the detected part is immediately determined. It is to be displayed.

During this time, the capacitor C8 in the potential tracking circuit (4) is rapidly charged based on the signal from the timer circuit (6) until the voltage of the capacitor becomes substantially equal to the voltage at one end of the sensor resistor. I'll keep it. Furthermore, after a predetermined period of time has elapsed to complete the rapid charging, the capacitor is slowly charged and discharged, and a follow-up operation is performed so that the voltage becomes equal to the voltage appearing at one end of the sensor resistor.

Further, after quick charging is performed by the timer circuit 6, the first
Since the output signal of the amplifier circuit (OPI) is disabled and the signal of the second amplifier circuit (OF2) that amplifies the voltage at one end of the capacitor is enabled, this time the second amplifier circuit (OF2)
The signals are applied to the output stage transistors (Tr, ., Tr++). Therefore, the display means (8) is a sensor resistor (
It is controlled based on the voltage at one end of the capacitor that follows the voltage at one end of R3 with a slow time constant.

[Effect]

With the above configuration, after a predetermined period of time has elapsed since the switch means for turning on power to the display means (8), the display means (8) is controlled by the voltage at one end of the capacitor, which charges and discharges at a slow time constant. Therefore, even if the detected portion is greatly displaced and the sensor resistance value suddenly fluctuates greatly, the voltage at one end of the capacitor does not change so much, and the deflection of the pointer of the display means does not fluctuate greatly. Therefore, the pointer does not swing sharply and is easy to see.

In addition, immediately after the switch means is turned on, the voltage at one end of the sensor resistor is directly transmitted to the display means (8) via the first amplifier circuit (OPI), so there is no display delay, and therefore, the voltage at one end of the sensor resistor is immediately transmitted as soon as the switch is turned on. The amount of displacement at that point can be grasped.

〔Effect of the invention〕

As described above, in the present invention, the amount of displacement can be displayed on the display means without any time delay immediately after the switch means is turned on, so that an observer looking at the display means can grasp the information immediately. I never feel uncomfortable. In addition, even if the displacement of the detected part fluctuates drastically due to disturbance, the display means will be driven by the voltage at one end of the capacitor after a while after the switch is turned on, so the pointer will not vibrate suddenly. , it is possible to accurately grasp the displacement level of the detected portion.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is a battery, 2 is a key switch, and 3 is a sensor portion, which is provided with a sensor resistor Rs and a fixed resistor R0. Reference numeral 4 denotes a potential follow-up circuit, which includes a comparator CP+ that compares the voltage at one end of the sensor resistor Rs with the voltage of the capacitor CI to control the transistor Tr and control the charging and discharging of the capacitor. It is being R1 and Rz are resistors, and Rx and Ra are resistors for charging the capacitor C1. Reference numeral 6 denotes a timer circuit, and a signal from the timer circuit 6 controls the transistor Tr via the resistor R1, and similarly the transistor Trh via the resistor R111.

When the transistor Tr is turned on, the transistor Tr is turned ON and the capacitor C1 is rapidly charged by the current flowing through the batch I71, the key switch 2, the transistor Tr4, and the resistor R11.

The timer circuit 6 has resistors R1 to R0, and when the voltage of the capacitor C2 increases due to the charging current from the battery, the comparator CP! outputs a low level signal, and the transistor Tr
, Tr are turned off. This stops the rapid charging of the capacitor CI, and the capacitor CI is charged via the resistor R3R4 and the transistor T
r, and the voltage V at one end of the resistor Rs is repeated.
It is controlled so that substantially the same voltage as IIS appears as VO2.

When transistor Tr= is turned off, transistor Trs
ONL, the first amplifier circuit OPI via diode Dz
The output of is considered invalid. Conversely, when the transistor Tr= is ONL, the signal from the second amplifier circuit OP2 is made invalid via the diode D. 8 is an ammeter type meter serving as a display means. Tr. , Tr, are output stage transistors.

The operation will be explained below. When the key switch 2 is turned on, the voltage of the capacitor C2 is charged with a time constant c2XR. And the voltage at one end of capacitor C2 is the reference voltage V
CCXRs / (R? +RI)... However, vCC is the constant voltage given to terminal Tc...
The output of comparator CP2 is Hi until the voltage reaches .
Since it is at the gh level, the transistors Tr and Tr
a*Tr h is ON. Therefore, the transistor Trs is turned off, and the output of the second amplifier circuit OP2 becomes Low level.

Therefore, the output of the sensor resistor Rs whose resistance value changes depending on the fuel level (v*s) ”-Rs/ (RO+R
s) XVCC has an amplification factor (1
+ Rrh/RI? ) is amplified. Therefore, the amount of displacement detected by the sensor resistor Rs is transmitted to the display means 8 without any time delay, and the pointer is immediately driven.

At the same time, the capacitor C1 is connected to the O of the transistor Tr4.
It is charged by N with a fast time constant C,XR,,. When the voltage of the capacitor CI becomes the same voltage as the voltage Vllll at one end of the sensor resistor Rs, the output of the comparator CP1 becomes Lo.
The level is switched from W level to High level, and both transistors Tr, Tr are turned on. This causes the transistors Tr, Tr.

is 0FFL, after this capacitor C3 is resistor R4゜R1
When the transistor Tr is turned on, it is slowly discharged through the resistor R4.

Afterwards, that is, after a predetermined period of time has elapsed since the key switch was turned on, the voltage of capacitor C2 changes to the reference voltage (Re
/ (Ry +Rs)XVCC), so
After that, the output of the comparator CP2 becomes Low level. Therefore, the transistors Tr, Tr.

is 0FFL, and even if a low level signal is output from the comparator CPI and the transistor Tr is turned off, the capacitor C1 will no longer be rapidly charged. Therefore, capacitor CI is repeatedly discharged or charged with a slow time constant C+XR4.

Further, since the output of the comparator CP2 becomes Low level, the transistor Trs becomes 0FFL, and as a result, the transistor Trs is turned on. Therefore, the output of the first amplifier circuit OPI is disabled, and the display means 8 is controlled by the output of the second amplifier circuit OP2. That is, the output of the comparator CP2 is inverted to low level, so that the transistor 3
When the FF is turned on, there is no current to bring the output of the second amplifier circuit to Low level via the diode D+, so the voltage VCI of the capacitor CI is amplified by the amplification factor (t+R5/R&) by the second amplifier circuit OP2, and this amplified The signal is applied to the output stage transistor T r Io +Tr, and a current is supplied to the display means 8 and the capacitor C3
This causes the pointer to oscillate depending on the voltage. Therefore, for example, when the fuel level shakes violently due to vehicle vibration, the float that detects the fuel level moves up and down violently.
Variable resistor linked to the float, i.e. sensor resistor Rs
Even if the resistance value of capacitor C1 fluctuates greatly, the voltage vcI of capacitor C1 gradually rises or falls. In other words, the capacitor C gradually increases with a delay operation of time constant C and XR4.
Since the voltage at I fluctuates, the pointer of the display means 8 controlled by this voltage will not swing suddenly (the pointer of the meter will move smoothly and will not fluctuate suddenly).

[Brief explanation of the drawing]

FIG. 1 is an electric circuit diagram showing an embodiment of the present invention, and FIG. 2 is an electric circuit diagram of a conventional circuit. l... Battery, 2... Key switch, 4... Potential tracking circuit, 6... Timer circuit, 8... Display means,
OPl...first amplifier circuit, OP2...second amplifier circuit, Tr. . Tr: Output stage transistor.

Claims (1)

[Scope of Claims] A sensor resistor whose resistance value changes depending on the amount of displacement of a detected portion, a first amplifier circuit that amplifies the voltage at one end of the sensor resistor, and a signal driven by the first amplifier circuit. an output stage transistor that is connected to the output stage transistor, and a display means that changes the position of the pointer depending on the amount of current flowing through the output stage transistor; a potential follow-up circuit having a capacitor that is charged to the same voltage as the display means; switch means for connecting a power source to the display means; A timer circuit generates a signal to rapidly charge the capacitor, and slowly charges the capacitor after a predetermined period of time, and a voltage at one end of the capacitor in the potential tracking circuit, and the amplified signal is used A displacement amount display device comprising a second amplification circuit that supplies an output stage transistor.