JPH0228477Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention operates a step motor using a reference oscillator signal or a signal obtained by frequency-dividing the reference oscillator signal, drives a wheel train by the step motor, and drives the wheel train. The present invention relates to a device for inspecting the operating characteristics of the step motor and wheel train of a timepiece that displays the time by the movement of each gear.

The purpose of this invention is to automatically test the operating characteristics of a step motor and a wheel train.

Another purpose of the present invention is to improve the accuracy of testing the operating characteristics of step motors and wheel trains.

Conventionally, in watches that drive the wheel train using a step motor, the step motor is very small.
In addition, its torque is very small, so even the slightest defect between the gears that make up the wheel train can cause malfunction, and misalignment between the rotor and stator of a step motor can cause malfunction. I get used to it. Therefore, it is important to carefully inspect the operating conditions of the step motor and wheel train. In order to perform this inspection, it would be possible to measure the torque at the end of the wheel train, but since the torque is extremely small, precise inspection would be difficult using measurement methods that involve mechanical contact, so this invention was devised. I've reached it.

The operating characteristic testing device for a step motor-driven timepiece according to the present invention includes a drive device 7 that drives a step motor 8, a current detection amplifier 9 that detects and amplifies the drive current of the step motor driven by the drive device. An AD converter 10 that converts the output of the current detection amplifier into a digital signal, a maximum value timing detection circuit 11 that detects when the initial and final maximum values 3 and 5 of the output of the current detection amplifier occur, and a medium-term minimum value. a minimum value time detection circuit 12 that detects the occurrence time of value 4; a sequence control device 13 that sequentially outputs instruction signals based on output signals of the maximum value time detection circuit and the minimum value time detection circuit; and the AD
an initial maximum value register 14 connected to the converter and storing the digital value of the initial maximum value 3 based on an instruction signal from the sequence control device; an intermediate minimum value register 15 storing the digital value of the intermediate minimum value 4; It has a final local maximum value register 16 that stores the digital value of the final local maximum value 5, and a subtraction device 17 that takes the difference between the initial local maximum value register and the intermediate local minimum value register. The present invention is characterized in that the operating characteristics of the step motor and the wheel train are tested based on the intermediate minimum value register, the final maximum value register, and the output value of the subtraction device. The present invention will be explained with reference to FIG. 1, which is a diagram of a step motor drive current waveform of a step motor driven timepiece, and FIG. 2, which is an embodiment of the present invention. When a rectangular wave drive voltage 1 shown in FIG. 1 is applied to a conventional step motor, a drive current waveform 2 flows. First, at the beginning of the square wave voltage 1, the current is 0 due to the inductance of the step motor coil.
Then, when the step motor starts to move due to the electromagnetic force of the current flowing through the coil, the dynamic impedance of the step motor increases and the current starts to decrease, and at the point where the dynamic impedance is maximum, it reaches the initial maximum value. becomes the minimum value. Thereafter, as the movement of the step motor approaches the target point, the dynamic impedance decreases and the current increases, and the current reaches its final maximum value at the final point of the drive voltage.

Therefore, if the initial maximum value 3 is too large, it means that the step motor does not start moving easily, and by dividing this value, the operating characteristics of the step motor and the wheel train can be inspected. Further, a large value of medium-term minimum value 4 means that the speed of the step motor is slow, and by dividing this value, the operating characteristics of the step motor and the wheel train can be inspected. Furthermore, the fact that the final maximum value 5 is small means that the step motor has not reached the target point, and by analyzing this value, the operating characteristics of the step motor and wheel train can be inspected. Can be done. Said 3
The two values are also affected by the battery voltage, battery impedance, switching element impedance, and magnetic circuit efficiency, and even if the initial maximum value is large and the intermediate minimum value is also large, the initial maximum value and intermediate minimum value may vary. If the difference is larger than a certain amount, it can be assumed that the step motor has rotated.For two reasons, by analyzing the difference 6 between the initial maximum value 3 and the intermediate minimum value 4, it is possible to more precisely It is possible to inspect the operating characteristics of step motors and wheel trains. Therefore, by analyzing one or a combination of the above three values, the operating characteristics of the step motor and the wheel train driven by it can be precisely examined. FIG. 2 is a block diagram showing an embodiment of the present invention based on the above theory, in which the current of a step motor 8 driven by a step motor drive device 7 is amplified by a current detection amplifier 9. The output of the amplifier is analog
A digital converter 10 (hereinafter abbreviated as AD converter) converts it into a digital signal. Furthermore, the output of the current detection amplifier 9 is the maximum value timing detection circuit 1.
1. A signal is sent to the minimum value timing detection circuit 12 and sent to the sequence control device 13 at the time when the maximum value and minimum value occur, respectively. In the sequence controller 13, the maximum timing signals are processed in a well-known manner, the first of which is sent to the initial maximum value register 14 as an initial maximum value latching pulse, and the second is sent as a final maximum value latching pulse. It is sent to the terminal local maximum value register 16. . Further, the minimum timing signal passes through the sequence control device 13 as it is and is sent to the intermediate minimum value register 15 as an intermediate minimum value latch pulse. In this way, the sequence control device 13 not only controls the stepping motor drive device 7 but also controls the maximum value,
When the minimum value occurs, the output of the AD converter 10 is stored in the initial maximum value register 14 and the intermediate minimum value register 1.
5. Store a digital value in each of the final maximum value registers 16 at the time of each occurrence. The subtraction device 17 is a device for taking the difference between the initial maximum value and the intermediate minimum value. The three types of registers 14,1
By analyzing the outputs of 5, 16 and the subtractor 17, the operating characteristics of the step motor and the wheel train driven by the step motor can be precisely examined. In addition, in this inspection method, by detecting the current of the finished watch body (movement) that includes the oscillation circuit, frequency division circuit, etc., the current consumed by the oscillation circuit and frequency division circuit is removed from the step motor drive. Since it is much smaller than the current at the time, it can be inspected almost ignoring other currents.

According to the present application, three digital values of the initial maximum value, intermediate minimum value, and final maximum value of the waveform value of the step motor drive current are used, and the three digital values are the battery voltage, battery impedance, switching element impedance, and magnetic Even if the initial maximum value is large and the intermediate minimum value is also large, if the difference between the initial maximum value and the intermediate minimum value is greater than a certain value, the step motor and wheel train will not rotate. Therefore, the operating characteristics of the step motor and the wheel train can be determined more precisely based on the initial maximum value register, intermediate minimum value register, final maximum value register, and output value from the subtraction device of the waveform value of the drive current. By being able to inspect the step motor and the wheel train driven by the step motor, it is possible to precisely inspect the operating characteristics of the part that has a problem with the operation of the machine at the time of inspection, and further inspection methods can be developed. It is a pure electric type and has advantages such as easy automation of operating characteristic tests, and its technical and economical effects are remarkable.

[Brief explanation of the drawing]

FIG. 1 is a diagram of a step motor drive voltage waveform and the resulting drive current waveform of a step motor driven timepiece, and FIG. 2 is a block diagram showing an embodiment of the present invention. 1 is a square wave drive voltage, 2 is a drive current waveform, 3 is an initial maximum value, 4 is a middle-term minimum value, 5 is a final maximum value,
6 is the difference between the initial maximum value 3 and the intermediate minimum value 4, 7 is the step motor drive device, 8 is the step motor, 9 is the current detection amplifier, 10 is the AD converter, 11 is the maximum value timing detection circuit, 12 is the minimum time detection circuit, 13
1 is a sequence control device, 14 is an initial local maximum value register, 15 is an intermediate local minimum value register, 16 is a final maximum value register, and 17 is a subtraction device.

Claims (1)

[Claims for Utility Model Registration] A drive device 7 that drives a step motor 8, a current detection amplifier 9 that detects and amplifies the drive current of the step motor driven by the drive device,
An AD converter 10 that converts the output of the current detection amplifier into a digital signal, a maximum value timing detection circuit 11 that detects when the initial and final maximum values 3 and 5 of the output of the current detection amplifier occur, and a medium-term minimum value. A minimum value timing detection circuit 12 that detects the timing of occurrence of value 4, a sequence control device 13 that sequentially outputs instruction signals based on signals from the maximum value timing detection circuit and the minimum value timing detection circuit, and the AD converter. An initial local maximum value register 14 that stores the digital value of the initial local maximum value 3 based on an instruction signal from the sequence control device, an intermediate local minimum value register 15 that stores the digital value of the intermediate local minimum value 4, and the final local maximum. It has a final maximum value register 16 that stores a digital value of value 5, and a subtraction device 17 that takes the difference between the initial maximum value register and the intermediate minimum value register, An operating characteristic testing device for a step motor-driven timepiece, characterized in that the operating characteristics of the step motor and the wheel train are tested based on the output values of the register, the final maximum value register, and the subtraction device.