JPS6223885B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a standard AC voltage generator that generates an AC standard voltage suitable for calibrating a standard voltage measuring device.

In conventional devices of this kind, it is generally possible to easily generate high-accuracy signals in a large output voltage range, but the output accuracy is poor in small output voltages around zero, and it is extremely difficult to output with high precision. Ta. Accurate zero voltage is required when zero-calibrating the measuring instrument to be calibrated for purposes such as zero adjustment, but since conventional standard AC voltage generators cannot generate accurate zero voltage, zero calibration is required. Only in certain cases, the signal input from the standard AC voltage generator was cut off, and the input terminal of the measuring instrument to be calibrated was directly short-circuited to provide zero input and zero calibration was performed. As described above, the conventional device has disadvantages in that it is troublesome to change the connection of the signal conducting wires, and in addition, it takes time to change the connections.

In view of these points, an object of the present invention is to forcibly set the output voltage to an accurate zero voltage and output it when the output voltage falls below a specific value near zero, so that the calibrator can be calibrated without changing the connection. It is an object of the present invention to provide a standard AC voltage generator capable of generating a standard voltage for performing calibration including zero calibration of a measuring instrument.

The present invention will be explained in detail below using the drawings. FIG. 1 is an explanatory diagram of the basic principle of the present invention. In Fig. 1, 1 is an output setting device that can specify the output voltage by setting a dial, 2 is a voltage generator that generates AC voltage,
It is controlled by an output setting device 1 and generates an output voltage corresponding to a dial setting value. 3 is voltage generator 2
This is an output changeover switch that selectively selects the output voltage or zero voltage, such as the common voltage. The output setting device 1 has its dial setting value, that is, the voltage generator 2
When the output voltage becomes below a specific value near zero, a zero output signal S is generated, and this signal S drives the raw power changeover switch 3 to select and output the zero voltage. Voltage generator 2 is reference voltage generator 2
1 and an amplifier 22. The reference voltage generator 21 generates a reference sine wave AC voltage signal. The amplifier 22 performs AC amplification of this sine wave signal, and its gain is controlled by the output setting device 1. It should be noted that the gain of the amplifier 22 may be fixed and the reference voltage generator 21 may be controlled by the output setting device 1 so that the designated voltage of the dial setting can be obtained from the amplifier 22.

The operation in such a configuration will be explained next.

(1) In the case of normal output state Voltage generator 2 generates a voltage according to the dial setting value of output setting device 1, and output selector switch 3
selects and outputs this voltage. For example, when the output setting device 1 is set to 100.23V, the amplifier 22 outputs an AC voltage of 100.23V via the switch 3.

(2) When outputting zero voltage When the dial setting value of the output setting device 1 is decreased and the setting value becomes below a specific value, the zero output signal S is generated from the output setting device 1 and drives the output changeover switch 3. In this case, the amplifier 22 outputs the designated voltage of the dial setting value, but the switch 3 does not select this designated voltage output, but selects and outputs zero voltage. In other words, if the specific value is specified as 1V, the upper digits are subtracted for each digit from the set value 111.23.
000.23, a zero output signal S is generated.
In other words, the lower two digits can be forced to generate an accurate zero voltage by operating the switch 3 without setting them to zero.

Note that the present invention can also be applied to a standard DC voltage generator. That is, a DC voltage generator is constructed by using the reference voltage generator 21 of the present invention as a reference DC voltage generator that generates a DC reference voltage, and the amplifier 22 as a DC amplifier. With this configuration, it is possible to output an accurate zero voltage regardless of the set value when the set value falls below a specific value, similar to the basic principle diagram device shown in FIG.

FIG. 2 is a configuration explanatory diagram for explaining another basic principle of the present invention, and is similar to that shown in FIG. 1 except that the output changeover switch 3 of FIG. It is the same as that of Second
In the configuration shown in the figure, when the zero output signal S is generated, zero voltage is input to the amplifier 22, so even though the set value is set below a specific value, the amplifier 22
outputs zero voltage at its output impedance.
Incidentally, in the case of a normal output state, the output voltage specified by the dial setting value is outputted as in the case of FIG. 1.

FIG. 3 is a block diagram showing an embodiment of the present invention, which is configured to digitally display the output voltage. In FIG. 3, parts equivalent to those in FIG. 1 are given the same reference numerals, and their explanations will be omitted. 31 is a setting value register that converts the dial setting value of the output setting device 1 into a code signal for display and stores it, 32 is a zero output register that stores a zero output code signal, and 33 is the output of the setting value register 31 or a zero output register. 32
A display selector switch that selectively selects the output of
Normally, the output of the set value register 31 is selected. 34 is a display switching device that receives the zero output signal S of the output setting device 1 and drives the display switching switch 33;
While the zero output signal S is applied, the switch 33 is driven at a predetermined cycle to alternately select the output of the register 31 and the output of the register 32. A display 35 digitally displays the signal selected by the display changeover switch 33.

In such a configuration, in a normal output state, the specified voltage of the dial setting value of the output setting device 1 is output from the output changeover switch 3, and the setting value is digitally displayed on the display 35. When the dial setting value is decreased and the value falls below a specific value, a zero output signal S is generated and the output selector switch 3
At the same time, the display changeover switch 34 operates and the display changeover switch 33 alternately selects the output of the set value register 31 and the output of the zero output register 32 at a predetermined cycle, and the display changer 34 outputs a zero voltage. Digitally displays the value and zero alternately. For example, subtract the upper digits from the setting value of 111.23 to 011.23→
When it changes from 001.23 to 000.23, the display 35 shows
Displays 000.23V and 000.00V alternately. This allows it to be recognized that although the dial setting value is 000.23, zero voltage is being output.

Note that the output code signal of the zero output register 32 is not limited to a zero signal, and may be a blanking code, for example. In this case, while the zero voltage is being output, the display 35 flashes the dial setting value so that it can be recognized that the forcibly selected zero voltage is being output.

In addition, the display changeover switch 33 may have a different configuration,
During zero voltage output, the display 35 shows zero (000.00)
It is also possible to configure the setting value to be displayed blinking in a normal output state outside the zero output region.

Note that the dial setting of the output setting device 1 can also be configured with a reference value dial for setting a reference value, a division dial for dividing this reference value, or a deviation dial for setting a deviation from the reference value.
In such a configuration, it is not very easy to directly read the specified value from the dial setting value, but the display on the display 35 allows the specified value and the actual output voltage to be read directly.

As explained below, according to the present invention, the output voltage can be forcibly set to zero in a range where the output accuracy near zero is poor. In this case, it is not necessary to completely set the dial setting value to zero, but only the upper digits need to be set to zero so that the value is below a specific value, so the operation is simple. When calibrating a measuring device to be calibrated using the standard AC voltage generator of the present invention, there is an advantage that even during zero voltage calibration, the calibration can be performed only by setting the dial on the output setting device without changing the connection of the signal conductor. .

Furthermore, since the actual output voltage can be equivalently displayed, it is extremely convenient to be able to recognize when the output voltage reaches zero without having to decipher the dial setting value. In addition, in a display mechanism that directly detects the output voltage and turns off the output lamp when the output voltage is zero, this is considered to be the same as when the output is turned off due to a power failure, but in the device of the embodiment, this is the case. Since this method does not cause any problems, it is highly effective in practical use.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the principle configuration for explaining the basic principle of the present invention, Fig. 2 is an explanatory diagram of the principle configuration for explaining other basic principles of the present invention, and Fig. 3 is a standard AC according to the present invention. FIG. 1 is a configuration explanatory diagram showing an example of a voltage generator. 1... Output setting device, 2... Voltage generator, 21...
...Reference voltage generator, 22...Amplifier, 3...Output selector switch, 31...Setting value register, 32...
...Zero output register, 33...Display changeover switch,
34...Display switching device, 35...Display device.

Claims (1)

[Claims] 1. A voltage generator that outputs a voltage according to the dial setting device, which is composed of an output setting device that specifies the output voltage by dial setting, a reference voltage generator that generates an AC reference voltage, and an amplifier that amplifies this reference voltage. , an output changeover switch that is driven by a zero output signal generated from the output setter and selectively outputs the output voltage or zero voltage of the voltage generator; and a code for displaying the setting value of the output setter. a set value register for converting into a signal and storing it; a zero output register storing a zero code signal; a display changeover switch for selecting either the output of the set value register or the output of the zero output register; and the display changeover. A display device that digitally displays the signal selected by the switch, and a display switching device that receives the zero output signal of the output setting device and drives the display switching switch, and when the dial setting value is below a specific value, A standard AC voltage generator characterized by outputting zero voltage and digitally displaying a dial setting value and zero alternately.