JPS6066179A - Capacitor-powered electronic clock - Google Patents

Abstract

PURPOSE:To raise a starting property from a stop state of an electronic timepiece by constituting so that a no-load leaving voltage balanced point of an electric double layer capacitor coincides roughly with an operation stop voltage of the electronic timepiece. CONSTITUTION:As for the way of dropping of a capacitor voltage E after an operation stop voltage D point, in case the D point is higher than a no-load leaving voltage balanced point, said way of dropping is larger than the case it is the same or lower. Accordingly, when the D point is set to the lower part than the C point, the voltage drop is small against a leaving state of a prescribed period, therefore, a starting property in case of charging from a primary power source is improved. In this regard, in case the D point is set lower than the C point, an obstruction is generated in a quality of an electric double layer capacitor. Therefore, when the D point is made to coincide roughly with the C point, the voltage drop becomes small, and a charging time can be shortened. In this way, a starting property from a stop state of an electronic timepiece can be raised.

Description

[Detailed Description of the Invention] The present invention was made to put into practical use an electronic timepiece that uses a capacitor as a power source, and is particularly intended to improve the starting performance when starting a stopped timepiece. .

About the proposal of electronic time opening using a capacitor as one source,
Although this invention has already been previously filed in Japanese Patent Publication No. 857-135850, it is an object of the present invention to provide a capacitor power supply electronics with improved practicality.

Capacitors that apply the electric double layer principle have been commercially available for many years now. This electric and gas double layer capacitor applies physical phenomena that inevitably occur on the surface of substances, so it has less performance deterioration than so-called chemical batteries such as alkaline manganese batteries and silver batteries, and in principle It is said to be semi-permanent or reversible as it becomes possible. Also, compared to conventional aluminum electrolytic capacitors, electric double layer capacitors have a capacitance IC of 101' to 10
? It is becoming possible to do this twice as much. It is the capacitance C(
This is because it is expressed by the following equation (11).

0”S/d ・・・・・・・・・・・・(1) Here S
is the surface area that bounds the two objects with charge, and d is the distance that maintains the insulation between the two objects. First, regarding S, by using activated carbon, the surface area per unit body mass is increased, and calculations show that it is possible to increase the surface area to about 1000/f.

Regarding d, since the electric double layer principle is a physical phenomenon, a thickness on the order of molecules is possible. This makes it possible to create a capacitor with high long-term reliability, which is about the size of a button battery and has a capacitance of about 0.1F to 2F.

On the other hand, the energy consumption of electronic watches, particularly mobile timepieces, is due to advances in MOS-IC technology.

The development of magnetic materials and liquid crystal materials has decreased significantly. Considering the level of current mobile watches, it is 1μW ~ 2μ
When it reaches a point where it can fully operate with W (A), if it reaches such a level, with the capacitor capacity of 1 as mentioned above,
1 to 18 days of operation 1 backup will be re-stretched. In addition, unless an amorphous solar cell is used as the primary N source because it has fewer restrictions on size and thickness, the solar cells produced during the day cannot be used.
1.The ideal long-life electronic clock can be obtained by using a capacitor to back up the operation at night.

However, when the above-mentioned capacitor is used as a backup for clock operation, the following problems occur.

It was like when I left it in my desk for several days. 1. If the backup time of the capacitor was exceeded and the supply of primary lightning, ren, tae [lifting 1 pond, X Niji] was stopped. If we consider the case where the voltage of the capacitor IJ decreases and the so-called 5-chair-f-yage state occurs, we would like to start the watch from this discharging state. In order to do this, you have to make an advance payment on the solar cell, which is the primary m source, and wait for the voltage to start at 1, which is the starting voltage for the clock body. This time will vary depending on the area of the solar cell, but if you consider it to be around 2 to 5 crl, which is the size of a mobile watch, it will be around 2 to 5 crl.
Only A Cheng's electric power can be taken out, and the time it takes to charge the capacitor is several minutes. During these few minutes, the user is unable to set the time, much less know the time. From a user's point of view, it is normal for users to want to immediately start a stopped clock to set the time, but leaving it exposed to direct sunlight for a few minutes will significantly reduce its marketability. In the past, it was not always possible to get direct sunlight easily, so if you could only get indoor light for a long time, it would take several tens of minutes or several hours, making it an incomplete product. I'm spoiled for becoming a thing.

Therefore, in an electronic watch powered by a C capacitor,
How quickly a product can be activated from a stopped state (startability) is necessary in order to increase marketability.

One way to improve start-up performance is to supply part of the primary energy from the solar cell directly to the watch body, then switch the excess energy to a switch circuit and supply it to the double layer capacitor that is the secondary power source. I can't think. Although this method is highly reliable, it has the following drawbacks.

1. There is a space loss and energy loss to incorporate the switch circuit on the IC.

2. It can operate even when the secondary power source is not connected, so if you inadvertently cut off the primary power supply (for example, by putting your watch in your sleeve), operation will stop and be delayed.

3. In order to support a drive system like analog quartz, which requires intermittent relatively large current (500 μ8 to 1 mA), a small auxiliary capacitor is required.

By the way, the discharge characteristics of an electric double layer capacitor can be seen from equation (2) as in the case of a normal capacitor.

P = Fioe-, ...... (2) Here, E is the residual voltage + KO is the initial voltage, R- (! is the time constant of the capacitor, t is E. The time (duration) for the voltage to drop, θ, is the base of the natural logarithm.

Here, by taking the logarithm of both sides of equation (2) to find the duration t, equation (3) is obtained.

1log E = −−t −1−log E,) −−
・= (312,3RC Therefore, the duration t is expressed by a linear expression of 1ogE.

Now, if we look at the no-load discharge from Eo of the electric double layer capacitor, it has the tendency shown in Fig. 1. A
A is loI! It's W o. Since it takes a very long time to completely integrate the electric double layer capacitor between A and B, it is an extremely difficult initial drop section in practical terms.
The part after B indicates the performance of this capacitor, and it has the property that the time constant changes slightly after C.

A small is used as the rated voltage, but it is determined by the electrolyte that forms this electric double layer capacitor, and in order to semi-permanently turn off the electric double layer capacitor, lightning It cannot be set above the decomposition voltage. For example, in the case of a Furayagi system using water, it is 1.2 V or less, and in the case of an organic system using a Li-based solvent, it is about 3 V. Safety for practical use and usage conditions is ^^, and the rated voltage is inorganic 0.
9■, organic type is set to about 2.0V. The C imaginary voltage exists at a scale of 20 to 30 degrees with respect to the rated voltage (AA pressure).There is no clear theory as to why the time constant changes, but lightning I don't think this is due to the force exerted by the fact that the overlapping layer is more stable and more likely to occur at lower voltages (voltage sufficiently lower than the rated pressure). In particular, this phenomenon appears more strongly as the time required for charging becomes shorter and longer. The 0 point will be referred to as the unloaded voltage balance force.

When using this capacitor as a power source, starting from the rated pressure A, the problem is whether to take the operating stop pressure here or there. It is better to avoid the heavy pressure of operation stoppage as much as possible.
Although more energy can be extracted, if the c-MO8IC is used to form a standard signal oscillation circuit and drive a motor for hand movement, as in Noriko Jigen 1, the operation stop voltage is 0.7 The voltage can only be lowered to ~0.9v.

Figure 2 (7) to (1) show the duration T and the three cases in which the operation stop frost 1 pressure is higher, equal to 1, and lower, with respect to the no-load voltage balance point C, in capacitors of equal capacity. This figure shows one discharge curve after the operation stop voltage is raised. As can be seen from Figure 2, it is natural that the lower the stop pressure, the longer the duration rIA+, but the way the capacitor voltage E decreases after the stop voltage is the no-load voltage equilibrium point C. If the operation stop voltage is high,
If the same value is lower, it means that the value is greater. Therefore, setting the operation stop voltage to a value slightly below the 0 point will result in less box pressure reduction when left unused for a certain period of time, and will therefore improve startup performance when charged from the primary power source. Become.

By the way, in order to obtain the operation stop snow pressure 'n from the unloaded voltage balance point C of all capacitors, there are the following obstacles.

As mentioned above, the stop voltage of electronic watches is 0.7 to 0.9.
V, whereas the voltage at the 0 point is 0.2~
o3v, approximately 0.4 to 0.5v in a specific system. For this reason, it is difficult to find a way to satisfy the above condition by connecting the capacitor cells in series with the product If l.

When capacitors are stacked in series, their capacitance -1
Since 'tlc decreases in inverse proportion to the number of laminated layers, the time constant also decreases, and therefore the voltage drop due to self-discharge increases, which is contrary to the original purpose.

However, the operating range of an electronic watch is difficult to reach half the value, which is so large, and especially when a motor is used, the operating range is close to the limit of about 2.0y to 0.7v. In the case of small watches, it is common to use a circuit and a motor powered by a Senshu battery, so the central value for the design is:
It is set to 1.5 to 1.6■. Therefore, the capacitor's rated pressure and operating voltage are 4 and 8 points are set to match the stiffness.

If the electrolyte of the electric double layer capacitor is inorganic, 2
~5 layers are required, and the rated voltage at this time is 1.8V ~ 2.7V
, the unloaded voltage balance point is 0.6 to 0.9V.

In addition, in the case of organic type, it is a single layer with a rated pressure of 2, Q 17,
The furnace load discharge voltage balance will be 04-0.5V.

Utilizing this result, one example of the actual foil of the present invention was 81'1.3
As shown in the figure. This example is a clock load simulation of a two-layer multilayer capacitor with a capacity of 0.5 F using an inorganic thread electric solution (H200T (2So)).
The duration at j+stop(0.7V)-j is 75 hours, with the no-load voltage balance point set at 0.6V, starting from the stop of operation. K to be activated in this state is that the charging lightning current from the solar cell, which is the primary power source, is exposed to direct sunlight 0.5
It changes by about 5 mA under O,2, so it is approximately -. . . 5-12
It starts up in about seconds (like a car that can be driven).

Therefore, even if the watch is left alone for about two weeks, it can be started up in a relatively short time, so it can be used in a practical manner for a long time.

If the operating point θ stop can be lowered to 06'V to match the pressure equilibrium point when left unloaded, the snow pressure drop can be extended for another 4.5 days, and the effect will be greater.

As mentioned above, if you use the properties of electric double layer capacitors to design a watch so that the equilibrium point between the stop voltage and the no-load voltage is as close as possible, it will be possible to start the watch in practice. It is possible to supply electronic time juice 1 in a range where the characteristics are not bothersome.

Generally, in electronic watches, the oscillation stop voltage of the crystal oscillator, which is a standard signal, and the drive stop voltage and voltage of the motor are set higher, but the attractive force of the permanent magnet used in the motor is set higher. By adjusting the oscillation stop voltage and the drive weight stop voltage to match the module operation stop voltage, it is possible to obtain an electronic clock with minimum loss.

Although the embodiment has been described in the case of an analog electronic timepiece, it can be similarly applied to a digital display type electronic timepiece that fully utilizes liquid crystals, etc.

As described above, by utilizing the properties of the electric double layer capacitor, it is possible to obtain a capacitor electric current electronic clock 41 that has sufficient practical possibilities without having a special load circuit.

[Brief explanation of drawings]

Figure 1 is a model diagram of a general no-load discharge curve of an electric double layer capacitor. Figure 2 is a model diagram of the radiation πj curve when load is taken into consideration. Figure 3 is a time-open load discharge curve of a double layer capacitor based on an embodiment of the present invention. Point A: Rated voltage point 0 point: No-load voltage balance point Am operation stop voltage point Figure 1

Claims (2)

[Claims] (1) An electronic timepiece having an electric double layer capacitor as an electric watch, characterized in that the N1 pressure equilibrium point of the electric double layer capacitor when left unloaded and the operating stop voltage of the electronic timepiece are made to closely match. Capacitor powered electronic clock. (2) As a charging means for the electric double layer capacitor,
The capacitor power supply 11 slave clock as described in claim 8f1 is characterized in that it is equipped with heavy oil.