JPH09322537A - Digital-to-synchro conversion method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid the discrepancies between the respective phases of the output voltages of synchro outputs, by a method in which adjusting resistors are connected in series to output terminals so as to make the respective resistance components of the secondary sides of respective transformers equal to each other when looking from the sides of the respective output terminal side. SOLUTION: In order to make the resistance components of the secondary sides 4b and 5b of respective transformers 4 and 5 equal to each other when looking from the sides of respective output terminals S1-S2, adjusting resistors +RS1 and +RS2 are connected in series to the 1st output terminal S1 and the 3rd output terminal S3. The adjusting resistors +RS1 and +RS2 are predetermined so as to be +RS1=R3-R1 and +RS2=R3-R2. Therefore, the resistance components of the secondary sides of the transformers are equal to each other when looking from the sides of the output terminals, and hence the output voltage levels of the respective phases of 3-phase synchro outputs 6 are equal to each other, so that the high precision control on the load side can be realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital / synchronous conversion method, and more particularly, to prevent the deviation of the output voltage between the phases of the synchro output by making the same resistances from the output terminals for obtaining the synchro output. Regarding new improvements in.

[0002]

2. Description of the Related Art As a digital / synchronous conversion method of this type which has been conventionally used, the method shown in FIG. 2 is generally adopted. That is, the reference numeral 1 in FIG. 2 is a D / A converter to which the digital angle input 2 is input, and the analog signal 1 a output from this D / A converter 1 is output to the first via the amplifier 3. , Second transformer 4,
5 is input to the primary side 4a, 5a. The secondary side 5b of the second transformer 5 is connected to the second output terminal S2 and also to the midpoint a of the secondary side 4b of the first transformer 4. First and third output terminals S1 and S3 are connected to both ends of the secondary side 4b of the first transformer 4.

Therefore, the digital angle input 2 inputted to the D / A converter 1 is D / A converted and inputted to the input sides 4a, 5a of the transformers 4, 5 through the respective amplifiers 3. Output terminals S1 to S of output sides 4b and 5b of the transformers 4 and 5, respectively.
A synchro output 6 composed of a three-phase AC signal is output to 3.

[0004]

Since the conventional digital / synchronous conversion method is configured as described above, there have been the following problems. That is, on the secondary side of each transformer, the resistance components R1, R2, and R3 of FIG. 2 exist, but these resistance components R1 to R3 are not the same, and if a load (not shown) is connected, the synchro output is obtained. Therefore, the output voltage is deviated, the accuracy of the synchro output 6 supplied to the load side is decreased, and the operation accuracy of the load side is decreased.

The present invention has been made to solve the above problems, and in particular, the resistances from the output terminal side for obtaining the synchro output are made the same, and the output voltage of the synchro output shifts between the phases. It is an object of the present invention to provide a digital / synchronization conversion method for preventing the above.

[0006]

Digital / digital according to the invention
The synchro conversion method is a digital / digital conversion method in which an analog signal obtained by inputting a digital angle signal to a D / A converter is output as a three-phase AC synchro output from three output terminals via a pair of transformers. In the synchro conversion method, a resistor for adjustment is provided in series with the output terminal, and the resistances on the secondary side of the transformers viewed from the output terminal side are the same.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the digital / synchronous conversion method according to the present invention will be described below with reference to the drawings. Note that the same or equivalent parts as those in the conventional example will be described using the same reference numerals. A reference numeral 1 in FIG. 1 denotes a D / A converter to which a digital angle input 2 is input. 2 transformers 4, 5
Is input to the primary side 4a, 5a of the. The secondary side 5b of the second transformer 5 is connected to the second output terminal S2 and also to the midpoint a of the secondary side 4b of the first transformer 4. First and third output terminals S1 and S3 are connected to both ends of the secondary side 4b of the first transformer 4.

Further, in order to make the first output terminal S1 and the third output terminal S3 have the same resistance components on the secondary sides 4b and 5b of the transformers 4 and 5 viewed from the output terminals S1 to S3 side, respectively. The adjusting resistors + RS1 and + RS3 are provided in series, and the resistors are configured to be the same when viewed from the output side. This adjustment resistor + RS3 is + RS
3 = R3-R2 and the resistance + RS1 is + RS1
= R3-R1 is set. Note that this resistor is provided not only in the first and third output terminals S1 and S3 but also in the other output terminal S2 if necessary.

Therefore, each of the output terminals S1 to S1 is connected by connecting the adjusting resistors + RS1 and + RS3 in series.
Since the respective resistance components from the S3 side are adjusted and set to be the same, the output voltage levels of the respective phases of the synchro output 6 composed of the three-phase AC signals output to the respective output terminals S1 to S3 have a conventional deviation. Without this, it is possible to obtain the synchro output 6 of the three-phase alternating current having substantially the same level.

[0010]

Since the digital / synchronous conversion method according to the present invention is configured as described above, the following effects can be obtained. That is, since a resistance for adjustment is provided in series with each output terminal, the resistance of the secondary side of the transformer seen from the output terminal side becomes the same, and each of the three-phase synchronized outputs output through each output terminal. The output voltage levels of the phases become the same level, and the load side control can be performed with high accuracy.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a digital / synchronization conversion method according to the present invention.

FIG. 2 is a configuration diagram showing a conventional digital / synchronization conversion method.

[Explanation of symbols]

 1 D / A converter 2 Digital angle signal 1a Analog signal 4,5 Transformer 6 Synchro output S1-S3 Output terminals 4b, 5b Secondary side + RS1, + RS3 Resistance for adjustment

Claims (1)

[Claims] 1. A digital angle signal (2) to a D / A converter (1)
Input analog signal (1a) to a pair of transformers (4,
In the digital / synchronous conversion method in which the three-phase AC synchro output (6) is output from the three output terminals (S1 to S3) via 5), the output terminals (S1 to S3) are adjusted in series. Resistance (+ RS1, + RS3) for each output terminal (S1 ~ S3)
A digital / synchronous conversion method characterized in that the respective resistance components on the secondary side (4b, 5b) of the respective transformers (4,5) viewed from the side are the same.