JPH01113670A - Rotation detector - Google Patents

Abstract

PURPOSE:To increase the precision of detection in the direction of rotation and to prevent the occurrence of a count error in a rotation pulse signal, by generating the rotation pulse signal delayed by a prescribed time width from a generation edge of an output signal of a two-edge detecting circuit. CONSTITUTION:Signals S2 and S1 of two different phases being synchronous with the rotation of a motor are inputted, the rising and falling edges of the input signal S1 are detected by the two-edge detecting circuit 20, and a pulse signal (b) of a prescribed time width is outputted therefrom. An FF circuit 30 receives an output (a) of an exclusive OR circuit 10 and the output (b) of the two-edge detecting circuit 20 as inputs and outputs from NAND circuits 34 and 35 a rotation direction output Y of which an L level and an H level are inverted. The output (b) of the two-edge detecting circuit 20 and an inverted clock signal are inputted to a rotation pulse generating circuit 40, a logical product is taken in an AND circuit 42 and a rotation pulse signal P delayed by a half period of the clock from the output (b) is generated. Accordingly, the rotation pulse signal delayed invariably from the rotation direction output Y when outputted can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a rotation detector for a motor used as a drive source for various audiovisual equipment.

BACKGROUND ART FIG. 3 shows the configuration of a conventional rotation detector, and FIG. 4 shows operating waveforms of each part in FIG. 3. The function of the rotation detector is to output rotation direction information of the electric motor and a rotation pulse signal associated with the rotation speed.

A two-phase signal s2 (
4(A)) and sl (FIG. 4(B)) are the D (data) terminal and CK of the flip-flop circuit 100, respectively.
(clock) terminal, and the output Q is the input signal sl
The state of the input signal S2 at the rising edge of is detected and output. In Fig. 3, Q is used as the output y (Fig. 4 (C)), so if the rotation direction is forward, y = “L
”, in the case of inversion, y=“H” is output as rotation direction information. Also, one phase of the input signal (sl in FIG. 3) is used as the rotation pulse signal p.

Problems to be Solved by the Invention However, in conventional rotation detectors, since the rotation direction output is detected only by the rising edge of one phase of the input signal, the reversal detection position may lag behind the actual reversal position. There is. Moreover, in FIG. 3, the input signal s1
is the clock (CK) of the flip-flop 100 and the rotation pulse signal p, and the flip-flop 100
Due to the gate delay of , the rotational direction output y lags slightly behind the rising edge of the human input signal sl. For this reason, for example, if the next stage of the rotation detector is operated with an up-down counter that counts up when the rotation is in the forward direction and counts down when the rotation is in the reverse direction, there is a problem that a counting error will occur. Ta. SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a rotary nebulizer that increases rotational direction detection accuracy and does not cause counting errors in the number of rotational pulses in the next-stage counter.

Means for Solving the Problems In order to solve the above problems, the rotation detector of the present invention enters one state when two pulse signals synchronized with the rotation of the motor and having different phases match, and changes to the other state when they do not match. a logic circuit that obtains an output signal that becomes , a double edge detection circuit that obtains a pulse signal of a predetermined time width at a rising edge and a falling edge of one of the two pulse signals, and an output signal of the logic circuit. a flip-flop circuit that maintains the state of when the pulse signals of the both edge detection circuits are generated; and a rotation pulse generator that obtains a rotation pulse signal that changes with a predetermined time width delay from the generation edge of the output signal of the both edge detection circuits. The configuration includes a circuit.

Operation The present invention can detect and output the rotational direction output at both the rising and falling edges of the input pulse signal with the above-described configuration. Further, the rotation pulse signal is always output later than the rotation direction output.

EXAMPLE Hereinafter, a rotation detector according to an example of the present invention will be described with reference to the drawings. FIG. 1 shows a specific circuit diagram representing one embodiment of the present invention. Reference numeral 10 denotes an exclusive OR circuit, and input pulse signals S2 and Sl, which are synchronized with the rotation of the motor and have different phases, are respectively input to two input terminals. 20 is a double edge detection circuit, which includes a first D-type flip-flop 21 and a second D-type flip-flop 2.
2 and an exclusive OR circuit 23. The D (data) terminal of the first D-type flip-flop 21 has
The input pulse signal S1 is input, and a CK (clock) signal is input to the CLK (clock) terminal. The D terminal of the second D-type flip-flop 22 is connected to the first D-type flip-flop 22.
It is connected to the output terminal Q of the type flip-flop 21, and the C
A CK multiplied signal is input to the LK terminal. One input terminal of the exclusive OR circuit 23 is connected to the output terminal Q of the first D-type flip-flop 21, and the other input terminal is connected to the output terminal Q of the second D-type flip-flop 22. . 30
is a flip-flop circuit, and impark circuit 3
1 and NAND circuits 32, 33, 34, and 35. One input terminal of the NAND circuit 32 is connected to the output terminal of the exclusive OR circuit 10, and the other input terminal is connected to the output terminal of the exclusive OR circuit 23.

The input terminal of the inverter circuit 31 is connected to the output terminal of the exclusive OR circuit 10. One input terminal of the NAND circuit 33 is connected to the output terminal of the inverter circuit 31, and the other input terminal is connected to the output terminal of the exclusive OR circuit 23. One input terminal of the NAND circuit 34 is connected to the output terminal of the NAND circuit 32, and the other input terminal is connected to the output terminal of the NAND circuit 35.

One input terminal of the NAND circuit 35 is connected to the output terminal of the NAND circuit 33, and the other input terminal is connected to the output terminal of the NAND circuit 33.
It is connected to output terminal 4. Reference numeral 40 denotes a rotation pulse generation circuit, which is composed of an inverter circuit 41 and an AND circuit 42. The input terminal of the inverter circuit 41 has CK
A double signal is input. One input terminal of the AND circuit 42 is connected to the output terminal of the inverter circuit 41, and the other input terminal is connected to the output terminal of the exclusive OR circuit 23. The output Y of the flip-flop circuit 30 is a rotation direction output, and the output P of the rotation pulse generation circuit 40 is a rotation pulse signal.

Regarding the rotation detector configured as above, the first
The operation will be explained using FIG.

FIG. 2 shows operating waveforms of each part of the rotation detector shown in FIG. 1. Input pulse signal S2 (Figure 2 (A))
, 31 (FIG. 2(B)) are input to the exclusive OR circuit 10, and when S2 and Sl do not match, the signal a becomes "H" level.
(Figure 2 (D)) is output. The input signal Sl is input to the D (data) terminal of the first D-type flip-flop 21 of the both edge detection circuits 20, and its output Q is the CK (clock) signal immediately after Sl (FIG. 2(C)). ) is synchronized at the rising edge of (Here, the CK multiplied signal frequency is
It is sufficiently higher than S2 and S1. ) 1st D type flip・
The output Q of the flop is input to the D (data) terminal of the second D-type flip-flop, and its output Q is a signal delayed by one clock period from the output Q of the first D-type flip-flop 21. is output. Exclusive OR circuit 23
are the first and second D-type flip-flops 212
When the two outputs do not match, an "H" level signal b (FIG. 2(E)) is output. As can be seen, the double edge detection circuit 20 detects the rising and falling edges of the input signal Sl and generates a pulse signal with a predetermined time width.

The flip-flop circuit 30 functions to hold the output a of the exclusive OR circuit 10 using the output a of the both edge detection circuits 20. To briefly explain the operation, a NAND circuit 32 receives the output a of the exclusive OR circuit 10 and the output of the both edge detection circuit 20, an inverter 31 inverts a, and inputs the output of the inverter 31 and b. A set of flip-flops composed of a number circuit 34 and a NAND circuit 35 and a reset signal are generated by a NAND circuit 33. As can be seen from FIGS. 2a and 2b, before the inversion position, the output of the NAND circuit 32 is at "H" level, and the NAND circuit 33 outputs an inverted signal of b. As a result, the output Y (FIG. 2(F)) of the flip-flop composed of NAND circuits 34 and 35 becomes "L" level. After the inversion position, the NAND circuit 32 outputs the inverted signal of b, and the output of the NAND circuit 33 is at the "H" level, so the flip-flop output Y reverses its state and outputs the "H" level. . As can be understood from the above explanation, this rotation detector detects the rotation direction using both the rising and falling edges of the input signal, unlike the conventional example, which detects the rotation direction only from the rising edge of the input signal. The detection accuracy is higher than when

The rotational pulse generating circuit 40 is composed of an inverter circuit 41 that inverts the clock and an AND circuit 42 that outputs the logical product of the output of the inverter circuit 41 and the outputs of both edge detection circuits 20. As described above, the output of the double edge detection circuit 20 detects the rising edge and falling edge of the input pulse signal and generates a pulse signal for one period of the clock synchronized with the rising edge of the clock. In the rotation pulse generation circuit 40, the AND of this b and the inverted clock is performed, so that the output P (second
Figure (G)) is a pulse signal for half a clock period synchronized with the falling edge of the clock. As a result, the rotation pulse signal P becomes a pulse signal that is delayed by half a clock cycle from the outputs of both edge detection circuits 20. Since the rotation direction is detected at the rising edge of the output of both edge detection circuits 20, the rotation pulse signal P is always output later than the rotation direction output Y. Also, this rotation pulse signal P
is generated at both the rising and falling edges of the input signal, so it is twice the frequency of the rotation pulse signal shown in the conventional example, that is, it is multiplied.

As described above, according to this embodiment, by detecting the mismatch state of the two-phase pulse signals synchronized with the rotation of the motor at both the rising and falling edges of the one-phase input pulse signal, the rotation direction can be determined with high precision. By delaying the output or the output pulse signals of both edge detection sections by a predetermined time width to obtain a rotation pulse signal, it is possible to obtain a rotation pulse signal that is always output later than the output in the rotation direction. Further, the specific embodiments of the rotation detector of the present invention are not limited to the above-described embodiments, and various modifications can be made without changing the gist of the present invention.

Effects of the Invention As described above, according to the rotation detector of the present invention, since the rotation direction output can be detected at both edges of the input cabling signal, the accuracy of direction detection can be improved.

Further, since the rotation pulse signal is always output with a delay from the rotation direction output, an excellent effect can be obtained in that a counting error does not occur in the next stage counter.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing an embodiment of the present invention, Fig. 2 is an operating waveform diagram of the embodiment, Fig. 3 is a circuit diagram showing a conventional rotation detector, and Fig. 4 is a conventional rotation detector. FIG. 10.23...Exclusive OR circuit, 20...
・・・Both edge detection circuit, 30...Flip・
Flop circuit, 40... rotation pulse generation circuit. Name of agent: Patent attorney Toshio Nakao Haka1 person-Qq
+ Target Q Figure 2 (C) CKJ knowledge ■° J Punishment - <G) P Figure 3 Figure 4 (C)! /

Claims (1)

[Claims] A logic circuit that obtains an output signal that is in one state when two pulse signals of different phases synchronized with the rotation of the motor match and becomes the other state when they do not match, and a rising edge of one of the two pulse signals. and a double-edge detection circuit that obtains a pulse signal of a predetermined time width at a falling edge, and a flip-flop that maintains the state of the output signal of the logic circuit when the pulse signal of the double-edge detection circuit is generated.
A rotation detector comprising a flop circuit and a rotation pulse generation circuit that obtains a rotation pulse signal that changes with a predetermined time delay from the generated edge of the output signal of the both edge detection circuits.