JPS5826274A - Level display circuit - Google Patents

Abstract

PURPOSE:To display the state existing in the middle of levels corresponding to two adjacent lamps, by comparing with the reference voltage and by controlling a light emitting element after the repeated waveform whose amplitude is changed linearly is overlapped on input voltage. CONSTITUTION:After an output of an oscillator 8 which generates low- frequency triangle wave through a capacitor 9 is overlapped, voltage X to be measured is applied parallely to input terminals of comparators 2-1-2-4. While, DC electric source voltage +Vcc is divided by a voltage divider consisting of resistances 3-1-3-5, and is added to -input terminals of the comparators. The output of the comparators 2-1-2-4 is applied to invertors 4-1-4-6 and AND gates 7-1-7-3 and one of light emitting diodes 5-5 in which a cathode side is made to a low level is turned on. By this way, the state that the input voltage level is in the middle of the reference voltage corresponding to two LEDs is recognized, and also it is understood that any one of two reference voltage is closer by checking the conditions of its flickering.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a visual level display using a lamp or the like.
This invention relates to a level display device.

A level display device using a lamp or the like uses a plurality of lamps or the like to display the level as a discrete value. Conventionally, methods for lighting lamps in such level display devices include lighting all of the lamps between the lamp representing the lowest level position and the lamp corresponding to the input level; , a method of lighting only the lamp corresponding to the input level, etc. has been used, but in any of these methods, the level at that time is two adjacent to each other.
If the value is between the levels corresponding to the individual lamps, usually only the lower lamps are turned on, and it is impossible to display the intermediate value. Therefore, in order to accurately display the level using such a level display device, an extremely large number of level display lamps must be used, which is impractical, and therefore, its use is limited to simple level display means. It was limited.

The present invention aims to eliminate such drawbacks of conventional contact, and the seventh object is to provide a level display device using lamps, etc., to display the level corresponding to each of two adjacent lamps. It is an object of the present invention to provide a display device that can represent such a state even in the case of an intermediate level, and can also represent which of the adjacent lamp levels is closer.

The level display device of the present invention includes an oscillator that generates a repetitive waveform whose amplitude changes linearly, and superimposes it on the output input voltage so that two adjacent input voltage levels can be displayed.
When the level is between the levels corresponding to the respective lamps, the two adjacent lamps are lit in an intersecting I pattern, and depending on the blinking status of these two lamps, the two adjacent lamps are It is possible to display the state of the input voltage level which is between the levels corresponding to the lamp.

Hereinafter, the present invention will be described in detail with reference to Examples.

FIG. 1 shows the structure of an embodiment of the level display device of the present invention. In the figure, 1 is a resistor for input signal coupling, 2
-1 to 2-4 are comparators, 3-1 to 3-! I is a resistor forming a voltage divider, 4-1 to 4-6 are inverters, 5-
1 to 5-5 are light emitting diodes (IJD), 6 is a current limiting resistor, 7-1 to 7-5 are AND gates, 8 is an oscillator (08C) that generates a low frequency triangular wave, and 9 is an oscillation r
This is a capacitor for coupling the output of XI8.

The input voltage X to be measured is applied in parallel to the (g) input terminals of each of the comparators 2-1 to 2-4 via a resistor 1.

On the other hand, the DC power supply voltage +VCC is divided by a voltage divider consisting of resistors 3-1 to 5-5, and the voltage at each voltage division point is applied to the (→ input terminals of comparators 2-1 to 2-4, respectively).

Now, resistors 5-1 and 3-2 t 5-2 and 5-3゜5-!
and 3-4, and the connection points of 3-4 and 5-5 are A, respectively.
B, C, and D, if the input voltage level
The cathode side of 5- becomes low level, and the power supply +VO
A current flows from C through the resistor 6 to the LED 5-1, causing it to light up.

When the input voltage level
-1 has a high level on the cathode side and no current flows, but inverter 4-3. Antogame) L after 7-1
The cathode side of the ED 5-2 becomes low level, and current flows from the power supply +VCC through the resistor 6 to the IJD 5-2, turning on the light. Similarly, when the input voltage level
D5-s lights up, and when the input voltage level X exceeds the potential at point C and is below the potential at point D, LID L4 lights up. Furthermore, when the input voltage level X exceeds the potential at point D, the output of comparator 2-4 becomes high level, and inverter 4
-6, the cathode side of LED5- becomes low level, and the power supply V (from 10 via resistor 6, LED5-,
K current flows and lights up. In this way, any one of the LEDs 5-1 to 5-5 lights up in response to fluctuations in the input voltage level.

Next, when the output of the oscillator 8 is coupled to the output side (point Y) of the input voltage coupling resistor 1 via the capacitor 9, the potential at the point Y fluctuates around the input voltage level in accordance with the output of the oscillation 11B. FIG. 2 shows changes in the potential at point Y, that is, the level at the (4) input terminal of each comparator, with respect to time t.

In the figure, X1 exemplifies the case where the input voltage level X is close to the point A potential, and X exemplifies the case where the input voltage level X is between the A point potential and the B point potential. In addition, in the same figure, Y, , Y, each have an input voltage level of X1*
It shows the level of point Y when Xs.

In Fig. 2, if the input voltage level is xl, the level at point Y is due to the superimposed triangular wave voltage.
It fluctuates as shown in YsK, and is shown in eight dengue (
In state 1), the level at point Y is below the potential at point A, so L
PID5-1 lights up and is indicated by eight-)
In the state of , the level at point Y exceeds the potential at point A, so IJ
D5-2 lights up. Therefore, in this state, IJD5-1
and 5-2 are lit alternately, and the proportion of the lighting time is the same when the input voltage level -1t or the lighting time of LED5-z is longer, and the degree of lighting time is greater as the difference between the input voltage level X and the potential at point A is greater.

On the other hand, if the input voltage level is , the level Y at point Y,
Since its positive and negative peaks are between the A point potential and B point potential, LED 5-2 is always lit, and LED 5-1 and LID
5-3 does not light up. In this way, 1 of the Y point potential
When 11N changes so as to cross the reference potential corresponding to adjacent LEDs, two LIilDs are lit alternately, and when it does not cross the reference potential, only one LFiD is lit.

In this way, in the level display circuit shown in FIG.
By superimposing the output of oscillation l18 on the input voltage,
If the input voltage level is between the reference voltages corresponding to two LEDs, you can know that this is the case, and depending on the blinking situation, the two adjacent LEDs
By not only knowing which of the reference voltages corresponding to
It is also possible to know whether the input voltage level is changing to the reference voltage of 0 IJD. In this case, the signal station wave number of oscillation 1) 8 is suitably 2Hs @ degree from the point of view of visibility, and its amplitude is slightly smaller than the difference in mu quasi voltage between two adjacent LEIDs. A small degree is appropriate. In addition, since the waveform is such that the change in blinking time is approximately proportional to the change in the input voltage level, it is desirable to use a repetitive waveform whose amplitude changes linearly with time, such as a triangular wave or a sawtooth wave. Furthermore, in the embodiment shown in FIG.
It goes without saying that the present invention can be similarly applied to cases where other types of information than IDs are used.

As explained above, according to the level display (b) path of the present invention, even when the input voltage level is between the levels corresponding to 62 adjacent display lamps, the input voltage Not only can you tell which side the level is closer to the level or approximately in the center, but also by looking at the change in the blinking status of the seven.
This is extremely effective because it allows us to know in which direction the input voltage level is changing, which allows us to obtain more accurate and detailed information about the input voltage level.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing the configuration of an embodiment of the level display circuit of the present invention, and FIG. 2 is an explanatory diagram showing a comparator input voltage waveform. 1: Resistor, 2-1 to 2-4: Comparator, 6-1 to 5
-s: Resistor, 4-1 to 4-6: Inverter, 5-1 to 5
-5 Two light emitting diodes (LED), 6: Resistor, 7-1~
7-s: AND gate, 8: Oscillator, 9: Capacitor Patent applicant Fujitsu Limited agent Patent attorney Gobe Tamamushi (3 others)

Claims (1)

[Claims] In a level display circuit that displays the input voltage level by comparing the input voltage level and a reference voltage and controlling the light emission of the light emitting element depending on whether the input voltage level exceeds the reference voltage, the amplitude changes linearly. 1. A level display circuit comprising an oscillator that generates a repetitive waveform, and superimposing the output of the oscillator on an input voltage.