JPS6029751Y2 - electronic clock - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to an electronic watch.

Electronic watches that use batteries or the like as a power supply source must use low voltage in each circuit that makes up the electronic watch in order to effectively utilize limited power.

The circuits that make up electronic watches, such as oscillation circuits, use elements that switch extremely many times, and consume very little power when stationary (-Even if MO3 elements are used, they must be operated at a sufficiently low voltage. In this case, it is difficult to reduce power consumption.

Further, the above voltage is not only low, but also makes the operation of the circuit unstable unless a stable voltage is maintained.

For this reason, conventional devices have been proposed in which, for example, a constant voltage circuit is built in and a low constant voltage is supplied to a circuit with a large number of switching operations, such as an oscillation circuit.

However, the batteries used in such devices generally have a low output voltage (for example, silver batteries have a voltage of about 1.57
bolt), the amount of transmission is also small.

Therefore, in electronic watches and the like, when some circuits temporarily consume a large amount of power, or when the power is turned on, the battery voltage drops.

Furthermore, the output voltage of the battery also decreases due to aging of the battery.

Therefore, even though a constant voltage circuit is built-in, if the battery voltage falls below the controllable range of the constant voltage circuit, not only will the stable operation of the constant voltage circuit be impaired,
The operation of the circuit operated by the constant voltage becomes unstable, and in some cases, the circuit may stop functioning.

The present invention provides a novel electronic timepiece that eliminates the disadvantages of conventional electronic timepieces, utilizes battery power without wasting it, and provides stable operation.

Hereinafter, the present invention will be explained in detail based on the illustrated embodiments.

In FIG. 1 showing an embodiment of an electronic timepiece according to the present invention, reference numeral 1 indicates a timepiece circuit.

The clock circuit 1 includes an oscillation circuit 2 using a crystal oscillator , which is supplied with a plurality of frequency-divided signals from the frequency dividing circuit 3 and includes a pulse signal generation circuit 5 that generates a predetermined pulse signal, and a drive circuit 6 that amplifies the pulse signal and converts it into a driving pulse. There is.

The output of the drive circuit 6 is transferred to a converter 8 incorporated in the clock mechanism 7.
to drive.

On the other hand, the battery voltage obtained from the built-in battery E is supplied to a constant voltage circuit 9, a battery voltage detection circuit 10, and a selection circuit 11, as well as a pulse signal generation circuit 5 and a drive circuit 6 of the clock circuit. Ru.

A constant voltage generated by constant voltage circuit 9 is supplied to selection circuit 11 .

Further, the output of the battery voltage detection circuit 10 is supplied to the selection circuit 11 together with the output of the pulse signal generation circuit 5 and the output of the flip-flop circuit 4.

The operation of the electronic timepiece according to the present invention having such a configuration will be described below.

The flip-flop circuit 4 of the clock circuit 1 is composed of two NAND circuits 12 and 13 to which the division signal output from the seventh frequency division stage of the frequency division circuit 3 is supplied, and the other input terminal is supplied with a reset pulse.

FIG. 2 shows a specific example of the flip-flop circuit 4 mentioned above.

Therefore, now, when input terminal A is supplied with a frequency-divided signal shown in waveform M in FIG. 3, and input terminal B is supplied with a reset pulse shown in waveform Ba, output terminal C receives a signal shown in waveform Ca. Output.

On the other hand, the pulse signal generating circuit 5 generates pulse signals Da at intervals of 1 second, and outputs two pulse signals Ea alternately, as shown in FIG. 4, for example.

Outputs Fa.

Further, in the battery voltage detection circuit 10, when the voltage of the battery E becomes lower than a predetermined level, a signal of logic r''OJ is outputted as shown by wave fa in FIG.

The selection circuit 11 to which such a signal is supplied includes, for example, a P-channel MOS transistor (hereinafter abbreviated as p-MO3T) 14 as a switch element, as shown in FIG.
It has a configuration including a channel MOS transistor (hereinafter abbreviated as N-MO5T) 15, a three-person AND circuit 16, and an inverter 17 that inverts the output of the AND circuit 16 and supplies it to the gate of the N-MO3T 15. ing.

A battery voltage is applied to the source of P-MO3T 14, a constant voltage is applied to the drain of N-MO3T 15,
Their drains and sources are connected to form the output side of the selection circuit 11.

The output of the flip-flop circuit 4, the output of the battery voltage detection circuit 10, and the pulse signal Da are supplied to the AND circuit 16 via an inverter 18.

Therefore, when the power is turned on, the output of the flip-flop circuit 4 is at the logic rO yo, R-MO3T14 is in the ON state, N-MO3T15 is in the OFF state, and the battery voltage is applied to the oscillation circuit 2 and the frequency dividing circuit 3. This makes it easier to start oscillation.

Furthermore, after the oscillation circuit 2 operates, when the frequency division signal of the seventh stage of the frequency division circuit 3 changes, the output of the flip-flop circuit 4 changes to logic 71J, so the p-MOS-14 becomes OF.
The F state is entered, and a low constant voltage is supplied to the oscillation circuit 2 and the frequency dividing circuit 3.

On the other hand, the battery voltage also decreases when the converter 8 is operated by the drive circuit 6.

However, at this time, since the pulse signal Da is being supplied, the battery voltage is applied to the oscillation circuit 2 and the frequency dividing circuit 3, and the stability of the operation can be improved.

Furthermore, when the voltage of the battery decreases due to aging, the selection circuit 11 outputs the battery voltage based on the output of the battery voltage detection circuit 10.

By selecting the battery voltage and constant voltage in this manner, the stability of the circuit can be improved, and the energy generated by the battery can be used without wasting it, making it possible to use the battery for a long time.

Although the present invention has been described above in detail based on the illustrated embodiments, the present invention is not limited to the illustrated embodiments, and various changes and improvements can be made.

For example, in the embodiment, the selection circuit 4 NIHAP-MO3T 1
4 T-N-MO3T 15 was used, but P-MO3T
It is also possible to use only 14, or even more than one p-MO
3T may also be used.

In this case, N-MO3Tl 5 may be removed and a constant voltage may be constantly applied to the output side.

Further, when selecting, for example, the battery voltage, a means for cutting off the supply of power to the constant voltage circuit may be used.

As described above, the electronic timepiece according to the present invention includes a selection circuit that selects between the battery voltage and the constant voltage in response to each output of the clock circuit and the battery voltage detection circuit, and when oscillation starts, the battery voltage higher than the constant voltage is selected. This makes it easy to obtain stable oscillation, and it also makes it possible to directly supply battery voltage even when a large amount of power is temporarily consumed when driving a converter, or when the battery voltage drops due to changes over time, improving the stability of the circuit. It is possible to achieve the intended purpose, such as being able to obtain sufficient power from the battery, and has great practical effects.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a diagram showing an embodiment of the electronic watch according to the present invention, FIG. 2 is a diagram showing a specific example of the flip-flop circuit in FIG. 1, and FIG. 4 is a waveform diagram for explaining the operation of the pulse signal generation circuit and battery voltage detection circuit in FIG. 1, and FIG. 5 is a waveform diagram for explaining the operation of the selection circuit in FIG. 1. FIG. 3 is a diagram showing a specific example. 1... Clock circuit, 2... Oscillator circuit, 3
...Frequency divider circuit, 4...Flip-flop circuit, 5...Pulse signal generation circuit, 6...
...Drive circuit, 9... Constant voltage circuit, 10...
...Battery voltage detection circuit, 11...Selection circuit, 14.15...MOS as a switch element
transistor.

Claims (1)

[Scope of utility model registration request] In an electronic clock consisting of an oscillation circuit, a frequency dividing circuit, a pulse signal generation circuit that generates a pulse signal for driving a converter, a driving circuit for the converter, etc., a battery that is the power supply source and a a constant voltage circuit that generates a constant voltage lower than this, an output generation circuit that generates an output for a certain period of time from when the battery is turned on, and a battery voltage detection circuit that generates an output when the voltage of the battery falls below a predetermined level. The voltage of the constant voltage circuit is supplied to the circuit, usually the oscillation circuit and the frequency dividing circuit, and the voltage of the battery is supplied when the output of the output generation circuit, the output of the battery voltage detection circuit, and the pulse signal are generated. An electronic clock consisting of a supply selection circuit.