JPH0452563A - Electronic watt-hour meter - Google Patents

Abstract

PURPOSE:To enable I/O setting while only a lithium battery is connected to be made in a no-voltage state by using a battery pack where a capacitor is connected to the lithium battery in parallel and allowing initial setting of I/O to be made during intermittent active period of calculation means. CONSTITUTION:An electric energy calculation means (microcomputer) 1 calculates and records arriving electric energy information in time units according to supply of electricity by a power supply part 2 based on AC power. Then, when this main power supply does not supply voltage, a lithium battery 12 for backup supplies voltage to the means 1 and a clock generator 8 for advancing time. At this time, a battery pack 14 for connecting a capacitor 13 for making constant battery voltage between a battery 12 and both electrodes is used. This capacitor 13 relaxes rapid reduction in supply voltage, prevents lack in advance of the timer 1a, and performs I/O initial setting during intermittent active period of the means 1 to be started under stabilization of the battery voltage.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an electronic energy needle.

[Conventional technology]

As shown in Fig. 4, the conventional electronic power amount needle includes a microcomputer 1 that has a built-in timer 1a and calculates and stores the input power amount (digital value) over time, and a microcomputer 1 that calculates and stores the input power amount (digital value) over time. a power supply section 2 that supplies power to the microcomputer 1 based on the power supply, a power outage/power restoration detection circuit 3 that detects the occurrence of a power outage and power restoration and sends a monitoring signal to the microcomputer 1, and a clock signal CL1 of 50 Hz or 60 Hz when energized. a waveform shaping circuit 4 that sends the oscillation frequency generated by the crystal oscillator 5 to the microcomputer 1; a frequency dividing circuit 6 that divides the oscillation frequency generated by the crystal oscillator 5 and sends the IHz clock signal CLz to the microcomputer 1; The configuration includes an 'IJ set circuit 8 for sending data to the computer 1. The source section 2 includes a power transformer 9 that transforms the commercial voltage, a rectifier/smoothing circuit 1o that rectifies and smoothes the transformed voltage, and a microcomputer 1 that stabilizes the smoothed voltage at a constant voltage and other circuits. It has a constant voltage circuit 11 that supplies power to the power supply, and a lithium battery 12 for power outage compensation (backup).

When the lithium battery 12 is left in an unused state (not energized), a film is formed on the electrodes, and the internal self-discharge becomes very slow, so it can withstand long-term storage. It is often used for power outage compensation (backup).

When the electronic watt-hour meter is energized, the waveform shaping circuit 4 outputs a clock signal CL of 50Hz or 60H2.

is supplied to the microcomputer 1, and based on this, the built-in timer 1a etc. function to calculate and store the constantly input power amount on a time-by-time basis. When a power outage occurs, the power outage/power restoration detection circuit 3 detects this, supplies a power outage detection signal to the microcomputer 1, and energizes the lithium battery 12 for power outage compensation, thereby causing the microcomputer 1 and others to circuits are supplied with backup power. When this backup is started, the microcomputer l automatically shifts to a low power consumption mode, and from the frequency dividing circuit 6 (DI
Built-in timer 1a by Hz clock signal C signal z
The timer (sidewalk) continues to operate even during power outages.

[Problem to be solved by the invention]

However, the electronic watt-hour meter using the lithium battery 12 for power failure compensation has the following problems.

■ When a power outage occurs, the lithium battery 12 becomes energized and enters a backup period, but at the beginning, the existence of the electrode film becomes an obstacle, and as shown in Figure 5 (A), the internal resistance of the electrode film causes the battery to The voltage will drop significantly once. Then, after the film is damaged by the circuit current, the battery voltage increases and settles down to a constant voltage. For this reason, there is a possibility that the initial drop in the battery voltage will be below the operating voltage of the microcomputer 1, which may cause a malfunction of the microcomputer 1 (the arrival of a reset signal due to lack of progress of the built-in timer 1a or activation of the reset circuit). Invite.

■ In addition, when the lithium battery 12 is loaded and connected without a power outage and the electronic watt-hour meter itself is in a no-voltage state (when starting up the battery power supply), as shown in FIG. 5(B),
Due to the internal resistance caused by the electrode film, the battery voltage suddenly drops below the operating voltage of the microcomputer 1, and the operating time of the microcomputer 1 is too short, making it difficult to set the input/output I10 of the microcomputer 1. Met. Moreover, this resulted in an unnecessary increase in circuit current.

Therefore, the present invention is intended to solve the above-mentioned problems.It is possible to set the input/output I10 by simply connecting a lithium battery in a no-voltage state, and even if a power outage occurs, the power outage compensation power supply voltage can be adjusted to a microcomputer. An object of the present invention is to provide an electronic power consumption needle that does not drop below the operating voltage of .

[Means to solve the problem]

In order to solve the above-mentioned problems, the means taken by the present invention include: a power amount calculation means that has a built-in timer and calculates and stores incoming power amount information in units of time; a main power supply section that supplies power to the main power source, a clock generator that generates a clock signal to run the built-in timer when the main power source is in a no-voltage state, and a power amount calculation means and a clock generator when the main power source is in a no-voltage state. In an electronic watt-hour meter equipped with a backup lithium battery that supplies power to a device, a battery back consisting of the lithium battery and a capacitor connected between the two electrodes is used to reduce the voltage of the main power source. Means is provided for performing an input/output initial setting operation during an intermittent active period of the power amount calculation means activated by loading the battery bag in the state.

[Effect]

According to this means, even when a lithium battery is loaded or a power outage occurs, the capacitors connected in parallel keep the battery voltage constant, so a sudden drop in the power supply voltage is alleviated. Therefore, the built-in timer can be prevented from not progressing properly and from malfunctioning of the reset circuit.

When a lithium battery is loaded and connected when there is no voltage, the power amount calculation means participates in an intermittent active period by clock input while the battery voltage is stabilized. Since the input/output initial setting operation is performed, the input/output initialization can be performed simply by loading the lithium battery even when there is no voltage, and the current consumption of the lithium battery itself is reduced.

〔Example〕

Embodiments of the electronic watt-hour meter according to the present invention will be described based on the accompanying drawings.

FIG. 1 is a block diagram showing the circuit configuration of an embodiment according to the present invention. In FIG. 1, the same parts as those shown in FIG. 4 are given the same reference numerals, and their explanations will be omitted.

In this embodiment, a lithium battery 12 for power failure compensation is used in the power supply section 2, but in order to suppress the voltage drop due to the internal resistance of the electrode film, a lithium battery 12 is connected in parallel with the lithium battery 12. A battery bag 14 consisting of a capacitor 13 of relatively large capacity is used.

When the battery bag 14 is loaded and connected to the power supply unit 2 in a non-voltage state of the electronic watt-hour meter, the charging voltage of the charged capacitor 13 suppresses the voltage drop due to the internal resistance of the electrode film of the lithium battery 12. Therefore, as shown in Figure 2,
The battery voltage charged to the microcomputer I is maintained above its operating voltage.

When the battery bag 14 is loaded as described above (at the time of start-up using batteries or when AC power as the main power source is supplied to the power transformer 2), the operation of the electronic watt-hour meter is executed as follows.

First, the reset circuit 8 outputs a reset signal to the microcomputer 1, and the microcomputer 1 participates in the first operation period of step 1 shown in the third figure, and as shown in step 2 of FIG. The initialization operation of the output I10 is performed, and the operation is stopped in step 3. The frequency dividing circuit 6 divides the frequency of the output of the crystal oscillator 5 and sends the first (i-1) clock shown in FIG. 2 to the microcomputer 1. As a result, the interrupt routine (NM) is started (step 4), and the microcomputer 1 starts operating again.

In step 5, the microcomputer 1 determines whether or not there is an intermittent end flag. Since this is the initial setting operation of the input/output I10, the intermittent end flag is not set at this point, so in step 6, i is set to the specified value for the number of intermittent times (for example, 4
) is equal to or not. Since i=1 at this point, the process moves to step 7, increments the count number of i-+i+1 by 1, and when the second zero-order clock occurs to end the interrupt routine, step 4 to step 7 Repeat the action. In this embodiment, when the fourth clock is generated, the process moves from step 5 to step 8, and the initial setting operation for the remaining input/output I10 is executed.

Then, in step 9, the intermittent end flag is set, and thereafter a signal from the power failure/power restoration detection circuit is awaited.

When a power outage occurs, the lithium battery 12 for power outage compensation becomes energized and starts supplying power to the microcomputer 1. However, since the lithium battery 12 is connected in parallel with a charged capacitor 13, its electrode film is Since the drop in battery voltage due to internal resistance is suppressed, built-in timer 1a
The lack of sidewalks does not occur, and the reset signal is not generated due to the operation of the reset circuit 8.
The power restoration detection circuit 3 detects the power failure and supplies the power failure detection signal to the microcomputer 1, which causes the microcomputer 1 to determine the presence or absence of the intermittent end flag at the next clock. At this point, the flag is set, so proceed to step 12 to process the power outage (sidewalk operation of built-in timer)
is executed, and in step 10 it is determined whether there is a power outage (power outage detection signal or power restoration detection signal). When the power is restored, each process (calculation and storage of electric energy over time, etc.) is executed continuously, ignoring the clock from the frequency dividing circuit 6, as usual. If there is still a power outage, the operation is stopped and step 5. is reached when the next clock arrives. Step 12° The operation of step 10 is repeated.

〔Effect of the invention〕

As explained above, the present invention is characterized by using a battery bag in which a capacitor is connected in parallel to a lithium battery, and initializing the input and output during the intermittent active period of the power amount calculation means. It has the following effects.

■ Even if a power outage occurs, it is possible to suppress the drop in battery voltage, and the built-in timer can prevent missing steps and reset malfunctions.

■ When a battery bag is loaded when there is no voltage, the battery voltage does not drop suddenly, so the time when the battery voltage is higher than the operating voltage of the power amount calculation means becomes longer, and an intermittent active period can be secured. Input/output initialization can be performed in a divided manner during this intermittent active period. Also,
It can reduce the current consumption of the loaded battery when there is no voltage.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the circuit configuration of an embodiment according to the present invention. FIG. 2 is a timing chart showing various signal waveforms in the same embodiment. FIG. 3 is a flowchart showing the operation mode of the same embodiment. FIG. 4 is a block diagram showing the circuit configuration of a conventional electronic watt-hour meter. Figure 5 (A) is a timing chart showing various signal waveforms when a power outage occurs in the same conventional example, and Figure 5 (B) is a timing chart showing various signal waveforms that occur when a lithium battery is loaded and connected in a no-voltage state in the same conventional example. FIG. [Explanation of symbols] 1...Microcomputer 1a...Built-in timer 2...Power supply unit 3...Power outage/recovery detection circuit 4...Waveform shaping circuit 5...Crystal oscillator 6... Frequency dividing circuit 8... Reset circuit 9... Power transformer 10... Rectifier/smoothing circuit 11... Constant voltage circuit 12... Lithium battery for power failure compensation 13... Capacitor 14...・Battery bag.

Claims (1)

[Claims] A power amount calculation means that has a built-in timer and calculates and stores incoming power amount information on a time-by-time basis; a main power supply unit that supplies power to the power amount calculation means based on AC power; and a no-voltage state of the main power supply. An electronic device comprising: a clock generator that generates a clock signal for incrementing the built-in timer; and a backup lithium battery that supplies power to the power calculation means and the clock generator when the main power source is in a no-voltage state. A power meter that uses a battery bag consisting of the lithium battery and a capacitor connected between both electrodes, and starts by loading the battery bag when the main power source is in a no-voltage state. An electronic watt-hour meter characterized by comprising means for performing an input/output initialization operation during an intermittent active period of the calculation means.