JPS622486Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a synchronized angle detector that converts a mechanical displacement angle into an electrical signal, and more particularly to a synchronous rectifier circuit for a synchronized angle detector that converts an AC voltage output into a DC voltage and sends it out.

The synchronized angle detector (hereinafter referred to as SG), which is conventionally used as a mechanical displacement angle detector, is one of the
When AC voltage is supplied to the secondary side, an electric signal of AC voltage corresponding to the mechanical displacement angle is generated from the secondary side.
The output characteristics of this SG are shown in Figs. 1 and 2. In other words, Figure 1 shows the relationship between the effective value of the AC voltage output and the mechanical displacement angle from +θ to -θ.
FIG. 2 shows the voltage phase relationship between the primary and secondary sides. In Fig. 2, Fig. 2a shows the primary AC voltage waveform, and Fig. 2b and c show the secondary AC voltage waveform when the mechanical displacement angle is on the +θ side and -θ side shown in Fig. 1, respectively. It is a voltage waveform. In an SG having such AC output characteristics, it is common to connect a synchronous rectifier circuit to the SG, synchronously rectify the output, convert it into a DC voltage, and use it as a DC output. Figure 3 shows the DC output characteristics obtained by synchronously rectifying the AC output characteristics shown in Figure 1.
On the other hand, FIG. 3b shows an embodiment in which the polarity is switched. This mode is selected depending on the directionality of the mechanical displacement angle due to the SG installation conditions or the control system that applies the DC output. When switching the polarity of this DC output, the SG secondary side is usually selected. There was a problem that required the cumbersome mechanical work of changing connections.

The present invention was devised to solve the above-mentioned problems, and provides a synchronous rectifier circuit that allows polarity switching to be performed simply and easily.

The present invention will be explained below based on the drawings.

FIG. 4 is a circuit diagram showing one embodiment of the present invention.
is SG, 2 and 3 are synchronization signal circuits, 4 is rectifier circuit,
5 and 6 are exclusive OR elements that output L level when two inputs are both H level or L level, and output H level when one of the two inputs is H level and the other is L level, and 7 is exclusive OR element. 9 is a transistor;
0 is a buffer amplifier with a gain of 1, 11 and 12 are filters consisting of resistors and capacitors, for example.
13 is a computing unit.

In FIG. 4, the synchronization signal circuit 2 inputs the primary AC voltage 101 of SG1 and generates a rectangular wave 104 which is at H level during a positive half wave and at L level when it is a negative half wave.
occurs. Similarly, the synchronization signal circuit 3 is SG1's 2
Next, a rectangular wave 105 is generated for the AC voltage 102. The rectifier circuit 4 inputs the secondary AC voltage 102 and performs full-wave rectification, and one of its outputs 103 is sent to the filter 1.
1 and the other is input to a filter 12 via a buffer amplifier 10. Therefore output 1
03 is filtered to a positive average value voltage by the filter 11, and is also applied to the filter 1 via the buffer amplifier 10 when the transistor 9 is not driven.
2 to a negative mean value voltage. Here, in the arithmetic unit 13 that adds the outputs 109 and 110 of the filters 11 and 12, the resistors R ₁ ,
Assume that the relationship between R ₂ and R ₃ is R ₁ = R ₃ = 2R ₂ .

Next, four modes of the apparatus shown in FIG. 4 will be considered and explained using FIGS. 5 to 8.

(1) When switch element 7 is off, the primary side of SG1 and 2
When the AC voltage on the next side is in phase (2) Switch element 7 is off and the primary side of SG1 and 2
When the AC voltage on the next side has a phase difference of 180° (3) Switch element 7 is on and the primary side of SG1 and the
When the AC voltage on the next side is in phase (4) Switch element 7 is on and the primary side of SG1 and the
When the AC voltage on the next side has a phase difference of 180°, the waveforms of each part in mode (1) are shown in Figure 5. That is, a and b are synchronous, and f is at H level. The secondary AC voltage 102 is passed through the rectifier circuit 4 so that its output 103 becomes c, and is further averaged by the filter 11 so that its output 109 becomes i. In addition, the rectangular waves 104 and 10 generated by the synchronization signal circuits 2 and 3
5 becomes d and e, and as a result, the output 108 is always at the H level like h, and the transistor 9 is always driven to make the input of the buffer amplifier 10 0V.
Therefore, the output of the buffer amplifier 10 is also zero, and the output 110 of the filter 12 becomes j. From this, the output 111 of the arithmetic unit 13 becomes k, which is the same as inverting the polarity of i.

(2) The waveforms of each part in mode are shown in FIG. That is, a and b have a phase difference of 180°, and f is at H level. Here, the difference from mode (1) is that the output 108 is always at L level like h and does not drive the transistor 9. Therefore, the output is 110 via the buffer amplifier 10 and the filter 12.
becomes j. At this time, i and j have different polarities but the absolute values are the same, and the value of the output 111 indicated by k becomes a DC output with a different polarity from that in mode (1).

In this way, the output 111 of the arithmetic unit 13 is obtained by synchronously rectifying the output 102 of the SG1, and the output 111
The output characteristics sent out by No. 1 in the above-mentioned (1) mode and (2) mode are as shown in FIG. 3b.

Similarly, the waveforms of each part in mode (3) and mode (4) are shown as shown in FIGS.
is synchronously rectified and its polarity is reversed, and its output characteristics in mode (3) and mode (4) are as shown in FIG. 3a.

This embodiment with such a configuration sends out a synchronous rectification signal with high precision, and the output polarity can be reliably electrically reversed by a simple and easy operation of turning the switch element 7 on and off. Note that the same effect can easily be obtained by replacing the switch element 7 with a logic element.

As described above, according to the present invention, it is possible to provide a highly accurate synchronous rectification circuit made of electronic components, and when switching the polarity of the synchronous rectification signal, there is no need to change the connection to the synchronized angle detector each time, making it simple and easy. It becomes possible to do so.

[Brief explanation of the drawing]

1 and 2 are diagrams showing the output characteristics of the synchronous angle detector, FIG. 3 is a diagram showing the output characteristics of the synchronous rectifier circuit, FIG. 4 is a circuit diagram showing an embodiment of the present invention, and FIG. 8 to 8 are waveform diagrams of various parts shown to explain the device shown in FIG. 4. 1... Synchro angle detector (SG), 2, 3...
Synchronous signal circuit, 4... Rectifier circuit, 5, 6... Exclusive OR element, 7... Switch element, 8... DC power supply, 9... Transistor, 11, 12... Filter, 13... Arithmetic unit .

Claims (1)

[Scope of utility model registration request] In a synchronized angle detector that converts a mechanical displacement angle into an electrical signal, a first synchronized signal circuit and a second synchronized signal circuit that generate rectangular waves synchronized with a primary alternating current voltage and a secondary alternating current voltage, respectively, of the synchronized angle detector. a signal circuit, a rectifier circuit that performs full-wave rectification of the secondary AC voltage, and a first exclusive OR element that inputs and connects the output of the first synchronizing signal circuit and a DC voltage that can be switched to a high level or a low level. and a second exclusive OR element that inputs and connects the first exclusive OR element output and the second synchronization signal circuit output,
a first transistor driven by the output of the second exclusive-OR element and a first transistor whose input is connected to the output of the rectifier circuit and filters the output of the rectifier to a positive average value voltage;
a filter circuit having a filter and a second filter that filters the voltage to zero voltage or a negative average value voltage by the transistor, and an arithmetic unit that performs an addition operation on the first filter output and the second filter output, A synchronous rectification circuit for a synchronized angle detector, characterized in that the polarity of a synchronous rectification signal sent from the arithmetic unit is switched by operation of the transistor.