JPS6055032B2 - Electronic clock with voltage judgment function - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic timepiece that detects the state of a built-in power supply and performs various controls based on the information.

Since dry cell batteries are normally used as the power source for electronic watches, the terminal voltage of the battery is constantly or periodically measured to notify the user that it is time to update the battery, and if the value falls below a certain value, a warning message is displayed. Products designed to excite are commercially available. Furthermore, when a warning condition occurs, there are proposals to increase the width of the drive pulse of the step motor by operating a waveform shaping circuit, for example, to compensate for the lack of torque due to voltage drop, or to perform the above measurement under a certain degree of heavy load, that is, with a low resistance value. By using the phenomenon that the internal resistance increases as the battery wears out and the terminal voltage drops further,
Proposals have been made to more accurately determine lifespan. If we examine this in detail, these technologies are still in their infancy, and we can bring them closer to the ideal.
The purpose of the present invention is to provide a means for more advanced power supply life warning and function control using only technologies that can be adopted in current mass production.
In an electronic watch having a power supply voltage determination circuit and a sampling means for intermittently putting the determination circuit into an operating state, the sampling means performs sampling when the electromagnetic converter is in a driving state and in a non-driving state. , controls the battery life warning display function based on the judgment output in the non-driving state,
This is an electronic timepiece with a voltage determination function, characterized in that a driving force control function is controlled by a determination output in a driving state. This will be explained below with reference to the drawings.

Taking as an example an iron oxide battery used in a wristwatch, FIG. 1 shows the relationship between discharge amount and terminal voltage, along with the effects of load and environmental temperature, using curve A) BNC.

If the threshold voltage of the power supply terminal voltage judgment circuit is set to V in the figure for a light load (for example, a circuit load excluding the converter of a watch), the influence of the environmental temperature will be small, and
In addition, since it crosses curve A only immediately before full discharge, it best serves the purpose of life warning. Even if the drive pulse is expanded after the warning, the battery will last only a few days, and even before the warning, under a heavy load equivalent to the converter coil, the curve B. ．． The terminal voltage drops considerably especially at low temperatures, as shown in C, but it is impossible to cope with this period, so in the case of extremely low temperatures, either be prepared for stopping due to insufficient torque, or set the normal pulse width to a large value. Therefore, the user has to put up with an increase in current consumption. Next, considering the case where judgment is made using the threshold voltage ■1 under heavy load (while the electromagnetic converter is running), the advantage is that the converter input can be effectively controlled during the latter half of the battery life or at low temperatures. On the other hand, the warning display is activated even though there is still plenty of battery life remaining, and the warning state that occurs at low temperatures disappears at high temperatures, which confuses users, so they are not impressed.

In the present invention, preferably one voltage judgment circuit is used, and this is preferably connected to light loads or heavy loads periodically and in a time-sharing manner, and the judgment output in each case is used to perform warning display control and other driving. It is an attempt to eliminate the above-mentioned drawbacks by independently performing force control and the like.

FIG. 2 shows the system configuration of an analog electronic timepiece according to an embodiment of the present invention.

FIG. 3 is a timing chart of the main waveforms. 1,
2 is a normal crystal oscillation circuit and a frequency divider circuit, and 3 is a drive waveform shaping circuit that synthesizes the outputs of each stage of the frequency divider to create a two-phase second pulse with a constant width. When receiving a width expansion signal or a warning display signal, it has a built-in logic gate that changes the combination of outputs from each stage of frequency division to create a different drive waveform.

Reference numeral 4 denotes a converter drive circuit, which drives an electromagnetic converter 7 based on the signal from the drive waveform shaping circuit 3, and displays the time using a hand movement display device 8.

Note that 9, 10, and 11 are the hour hand, minute hand, and second hand. 12 is a battery for power supply; 13 is a battery voltage determination circuit for detecting a voltage drop of the battery 12; two data type flipflops (hereinafter abbreviated as DFF) 14;
15 and a P-channel MOS transistor 16, the drain voltage terminal of the MOS transistor 16 is connected to the data terminal D of the DFFl4 and DFFl5, and the voltage of the battery 12 is connected via the level adjustment resistor 17.
dd terminal, and the source terminal of the MOS transistor 16 is connected to the Vss terminal of the battery 12.

Reference numeral 18 denotes a sampling pulse shaping circuit, which converts signals from the frequency dividing circuit 2 and the drive waveform shaping circuit 3 into an electromagnetic converter 7.
A heavy load sampling signal φ1 in the driving state and a light load sampling signal φ2 in the non-driving state are generated.

Each sampling signal is connected to the sampling terminal φ of DFFl4 with φ1 connected to the sampling terminal φ of DFFl5, and φ2 connected to the sampling terminal φ of DFFl5.
It is connected to the gate terminal of the MOS transistor 16 via.

20 is a pulse width control circuit which, upon receiving the driving force control signal from the output terminal Q1 of the DFF14, supplies a pulse width enlargement signal to the drive waveform shaping circuit 3 to increase the drive pulse width, and controls the electromagnetic converter 7. Increase driving force.

Reference numeral 21 denotes a warning control circuit, and upon receiving a warning control signal from the output terminal Q2 of the DFF15, the driving waveform shaping circuit 3
A display modulation signal is supplied to modulate the operation of the hand movement display device 8, and a battery life warning is issued.

22 is an oscillation operation control circuit, which operates the oscillation circuit 1 upon receiving the driving force control signal from the output terminal Q1 of the DFFl4.
The oscillation operation is enhanced by increasing the voltage supplied to the oscillator.

Next, the operation of the battery voltage determination circuit 13 will be explained.

A light load sampling pulse φ2 generated by the sampling pulse shaping circuit 18 at a timing when the converter 7, which has a heavy load, is not driven is passed through the 0R gate 19 to the M
It is applied to the gate terminal of the OS transistor 16 and simultaneously applied to the sampling terminal φ of the DFF15.

At this time, if the voltage of the battery 12 is high, the MOS transistor 16 is sufficiently turned on by the sampling pulse φ2, so that the data of the DFF15 connected to the dividing point between the MOS transistor 16 and the level adjustment resistor 17 is The level of the terminal D becomes the logic ゜゜0゛, so the output terminal Q2 is kept at the logic ``0'' level.
When the life of DFF15 approaches and the voltage decreases, the sampling pulse φ2 cannot turn on the MOS transistor 16 sufficiently, and the data terminal D of DFF15 becomes
Since the level of is the logic ゜゜1゛, the logic ``゜1゛ level is written to the output terminal Q2 as a battery life warning control signal.

Similarly, the result of voltage determination using the heavy load sampling pulse φ2 generated at the timing of driving the converter 7 is written as a driving force control signal to the output terminal FQl of the DFFl4.

The voltage level at which the battery voltage determination circuit 13 operates can be set to any value by adjusting the level adjustment resistor 17.

Therefore, in the battery voltage determination circuit 13, only one operating level is set by one level adjustment resistor 17, so when the battery 12 approaches the end of its life and its internal resistance increases, a heavy load is applied. Because a voltage drop occurs due to
First, by heavy load sampling pulse φ1, DFFl4
A drive control signal is written to the output terminal Q1 of the DFF15, and when the battery voltage further decreases, a battery life warning control signal is also written to the output terminal Q2 of the DFF15, resulting in a double detection structure.

Next, the operation of the electronic timepiece shown in FIG. 2 will be explained using the waveform diagram shown in FIG.

3 oscillated by the oscillation circuit 1 as shown in FIG.
The reference signal of 2768Hz is frequency-divided by the frequency divider circuit 2, and 64Hz is applied to the F9 terminal as shown in FIG. 3B, c, d, and e.
Hz. ．． 1Hz to F15 terminal. ．． 0.5H to F16 terminal
It generates signals such as z.

The drive waveform shaping circuit 3 receives the signal from the frequency dividing circuit 2, generates drive signals with different waveforms according to conditions described later, and drives the converter 7 via the drive circuit 4 to display hand movement. The time is displayed on the device 8.

The sampling pulse shaping circuit 18 is shown in FIG. ．． As shown in g, a heavy load sampling pulse φ1 synchronized with one of the alternating pulses for driving the converter and a light load sampling pulse φ2 not synchronized with any of the alternating pulses are generated.

Next, a series of control operations accompanying the determination operation of the battery voltage determination circuit 13 will be explained.

First, during normal operation when the voltage of the battery 12 is high, the driving force control signal and the battery life warning control signal are not written in DFF14 and DFF15 that constitute the battery voltage determination circuit 13, so the pulse width control circuit 20, Warning control circuit 21
, the oscillation operation control circuit 22 are both in a non-operating state, and in this state, the oscillation circuit 1 is operating at a low voltage level, and the drive signal from the waveform shaping circuit 3 is as shown in FIG. 3h. 64Hz (F1) with a period of 1Hz (Fl5)
9) is generated, and the second hand 11 of the time display device 8 is moved at a constant speed at a period of one second.

Next, when the life of the battery 12 is nearing and a driving force control signal is written to the output terminal Q1 of the DFFl4 by heavy load sampling, the pulse width control circuit 20 and the oscillation operation control circuit 2
The second compensation function circuit becomes operational, the oscillation circuit 1 switches to high voltage level operation, and the period of the drive signal from the waveform shaping circuit 3 does not change as shown in Figure 3, only the pulse width increases. (for example, 32 Hz), and the driving force of the converter 7 is enhanced.

Next, when the battery 12 approaches the end of its life and a battery life warning control signal is written to the output terminal Q2 of the DFF14, the warning control circuit 21 also enters the operating state, and the drive signal from the waveform shaping circuit 3 changes as shown in FIG. There are two alternating pulses every 2 seconds as shown in j.

As a result, the second hand 11 of the hand movement display device 8 changes speed in two steps every two seconds, thereby displaying a battery life warning. As described above, according to the present invention, by properly using the functions of the battery voltage determination circuit, it is possible to guarantee the safety of the minimum required functional operation, check the operation of additional functions, design power saving during normal times, provide appropriate warnings, and adjust the circuit configuration and assembly. This invention has the remarkable advantage of simultaneously satisfying various demands such as preventing excessive complexity of work, and the present invention also performs stepwise detection of battery voltage by changing the load current at the time of sampling. Since it essentially requires only one judgment circuit and one external low resistor for level adjustment, the number of external parts and assembly steps is reduced compared to the conventional battery voltage judgment method. There is no increase.

[Brief explanation of the drawing]

FIG. 1 is a discharge characteristic diagram of a watch battery, FIG. 2 is a block diagram of an electronic timepiece according to the present invention, and FIG. 3 is a waveform diagram of each part in FIG. 2. 1... Oscillation circuit, 2... Frequency dividing circuit, 3
... Waveform shaping circuit, 7 ... Electromagnetic converter, 8 ... Hand movement display device, 12 ... Battery, 13 ... Battery voltage Judgment circuit, 18...
- Sampling pulse shaping circuit, 20...pulse width control circuit, 21...warning control circuit.

Claims (1)

[Claims] 1. A reference oscillator, an electronic circuit, a time display means, an electromagnetic converter that drives the time display means, a drive circuit that drives the electromagnetic converter, and a warning control circuit that supplies a modulation signal for battery life warning display to the drive circuit. , an electronic timepiece having a battery, a voltage determination circuit for detecting a voltage drop in the battery, and a sampling means for intermittently activating the voltage determination circuit,
A compensation function circuit is provided for increasing the driving force of the reference oscillation circuit, the drive circuit, etc., and the sampling means is provided with a sampling selection means for sampling in a driving state and a non-driving state of the electromagnetic converter. A determination output of the voltage determination circuit in a non-driving state controls the warning control circuit to display a battery life warning, and a determination output in a driving state controls the compensation function circuit and drives the circuit. An electronic watch with a voltage judgment function that is characterized by increasing power.