JPS5833798B2 - Clock motor motion detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an operation detection device for a watch motor used in a watch, time switch, or the like.

Due to its nature, watch motors are expected to rotate normally at all times, so if any abnormality causes the motor to rotate out of sync or stop, this condition is detected and an abnormality signal is issued. An example of this is to detect the presence or absence of vibrations of the rotor that occur as the rotor rotates.

However, this method requires a highly accurate amplification circuit, making the configuration complex and expensive.

The present invention was made with the aim of solving the problems of the conventional example, and compares a constant level reference voltage with a voltage obtained from a motor drive circuit that fluctuates depending on the operation of the motor. The present invention provides a motion detection device for a watch motor that can detect motion with a simple configuration by detecting the difference between the two mold pressures and obtaining a motor motion determination signal using a comparison circuit.

Hereinafter, the present invention will be explained with reference to the illustrated embodiments.
In the figure, 1 indicates the oscillation output of the crystal oscillator 2 at a predetermined frequency (
This is a clock IC that converts it into a pulse signal (for example, 16 Hz) and outputs it, and the pulse signal output from the clock IC 1 is input to the signal terminal 1a and is connected to the voltage doubler capacitor C.
1 to the base of the switching transistor Q1.

A drive coil 3a of the motor 3 is connected in series to the emitter of the switching transistor Q1, and a series circuit consisting of a detection coil 3b for detecting the rotation of the rotor 3c and a resistor R3 is connected in parallel between the emitter and the base. There is.

Reference numeral 4 denotes a comparison circuit consisting of a transistor Q2, which compares the voltages vB and vE across the capacitor C1 and outputs a motor operation determination signal s depending on whether a predetermined potential difference is obtained.

In the figure, R1 is a base resistance, and R2 is a collector resistance.

5 is an abnormality display element (such as a buzzer or lamp) provided as appropriate.
(not shown), the base of the first stage transistor Q3 is connected to the collector of the transistor Q2 via the resistor R4, and the capacitor C2 inserted in the collector resistor is charged and discharged according to the output of the transistor Q2. It has become.

Figure 2 shows the voltages VB and ■E across the capacitor C1.Figure a shows when the rotor 3c of the motor 3 is rotating normally, and figure b shows when the rotor 3c is stopped. .

As is clear from this figure, in this embodiment, the voltage vB is the reference voltage, and when the rotor 3c is rotating, there is a portion A where the voltage VB is larger than the voltage vE, but when the rotor 3C stops, the voltage While vB does not change as the pulses at the same level as before continue, voltage vE becomes less steep as the level increases and part A disappears, so by detecting the presence or absence of this part A, the motor It is possible to detect the rotational state of the

To describe this operation in more detail, the clock IC
Since the pulse signal output from the capacitor C1 is constant regardless of the rotation of the motor 3, the voltage vB at one end of the capacitor C1 always becomes a pulse signal having a constant waveform, and is applied as a reference voltage to the base of the transistor Q2.

By the way, at 1o-1°, the capacitor C1 is connected to the drive coil 3as, the detection coil 3b and the resistor R from the power source.
3, the voltage vE at the other end of the capacitor C1 gradually rises, and instantaneously rises at t□ when the voltage 8 at one end rises.

Next, from t1 to t2, the charge in the capacitor C1 is discharged via the resistor R3, the detection coil 3b, the drive coil 3a, and the clock ICI, and at t2, the charge in the capacitor C1 is completely discharged.

Here, if the rotor 3c is rotating synchronously, the rotor 3c
A voltage (back electromotive force) is generated in the drive coil 3a and the detection coil 3b due to a change in the magnetic flux of the first drive coil 3as and the detection coil 3b due to the rotation of the first drive coil 3as and the detection coil 3b.

Therefore, the voltage vE at the other end of the seventh capacitor C1 gradually drops by the voltage valve of the drive coil 3as and the detection coil 3b.
Part A is generated where ■3>■E.

Furthermore, at t3 when the voltage VB at one end falls, the voltage at the other end becomes ■.

also drops rapidly and becomes ■E<0.

At this time, the voltage across the detection coil 3b and the resistor R3 is equal to the base-emitter voltage VBE of the switching transistor Q1.
, a base current flows through the switching transistor Q1, turning on the switching transistor Q1, a large collector current flows through the drive coil 3a, the rotor 3c is repelled by the magnetic force generated in the drive coil 3a, and the rotor 3c is rotated. It has become so.

Thereafter, in the same manner, the drive coil 3a is excited in synchronization with the pulse signal output from the clock C1, and the motor 3 rotates synchronously.

Here, as shown in FIG. 3, the voltages VB and ■E across the capacitor C1 are applied to the base and emitter of the transistor Q2 constituting the comparison circuit 4, respectively, and from t2 to
At t3, vB-v.

When ≧vBE, transistor Q2 turns on and current ■! flows, and an operation determination signal 8 consisting of a negative pulse indicating that the motor 3 is rotating is output as a collector output.

On the other hand, when the rotor 3c of the motor 3 is stopped,
Drive coil 3a.

Since no voltage is generated in the detection coil 3b due to the rotation of the rotor 3c, the voltage at the other end of the capacitor C1 is ■.

The voltage at one end never becomes lower than VB, the transistor Q2 of the comparator circuit 4 never turns on, and the motor 3
The °H"H" level determination signal V8 indicating that the motor is not rotating is always output.

Depending on the presence or absence of this operation determination signal v8, the operation circuit 5 is driven, and for example, when the motor has stopped, it is reported by sounding a buzzer or lighting a lamp.

FIG. 4 shows the relationship between the voltage waveforms at this time, and FIG. 4 shows the waveforms when the rotor 3c is rotating normally, and FIG. 4 shows the waveforms when the rotor 3c is stopped.

As described above, the present invention provides a clock IC that outputs a predetermined frequency to the base of a switching transistor, the emitter of which is connected in series with a motor drive coil, and a detection coil that detects the rotation of the rotor is connected in parallel between the emitter and the base. A comparator circuit is installed that applies a rectangular wave signal through a capacitor, compares the voltage across the capacitor, and outputs a motor operation judgment signal depending on whether a predetermined potential difference is obtained. In other words, a comparison circuit compares the clock IC output, which is constant regardless of the rotation of the motor, and the base input of the switching transistor, which varies depending on the rotation of the motor, and outputs an operation judgment signal depending on whether a predetermined potential difference is obtained. Therefore, the operation of the motor can be reliably detected by simply adding a comparison circuit that can be formed using only a few circuit elements, creating a simple and inexpensive operation detection device for watch motors. There are benefits it can offer.

[Brief explanation of drawings]

FIG. 1 is a wiring diagram of an embodiment of the present invention, and FIG. 2a is a diagram. b is a voltage waveform diagram of the main part same as above, FIG. 3 is an explanatory diagram of the same operation as above, and FIGS. 4 a and b are voltage waveform diagrams explaining the same operation as above. 3 is a motor, 4 is a comparison circuit, R1-R2 is a resistor, C1 is a capacitor, and Q2 is a transistor.

Claims (1)

[Claims] 1 A pulse signal of a predetermined frequency outputted from a clock IC is passed through a capacitor to the base of a switching transistor whose emitter is connected in series with a motor drive coil and a detection coil for detecting rotor rotation is connected in parallel between the emitter and base. 1. An operation detection device for a watch motor, characterized in that a comparison circuit is provided which outputs a motor operation determination signal depending on whether a predetermined potential difference is obtained by comparing the voltages across the capacitor.