JPH01195559A - Back-up memory for electronic equipment - Google Patents

Abstract

PURPOSE:To ensure the writing of data when a voltage drop is detected by performing the writing control of the prescribed data to a memory means when the voltage of a low level is detected and only when a period when no voltage drop is detected is longer than the charging time of a back-up power supply part. CONSTITUTION:An arithmetic control means 9 performs no writing control to a memory means 8, if a period when the drop is not detected for the power supply voltage counted by a clocking means 11 does not exceed the charging time of a back-up power supply part 10 for the satisfactory writing control in case the voltage of a low voltage is detected by a low voltage detecting means 7. As a result, the writing control is carried out only when the part 10 is satisfactorily charged. Thus, it is possible to avoid the writing failure of the prescribed data to the means 8 due to the drop of the voltage level of the part 10.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a backup storage device for electrical equipment that backs up setting conditions, etc. so that the state will be the same as before when starting up from a power outage or when the power is turned on again. It is.

2. Description of the Related Art Conventionally, a bank-up storage device for this type of electrical equipment has had a configuration as shown in FIG. In the figure, 1 is a commercial power supply unit, 2 is a low voltage detection means, 3 is a storage means for storing predetermined data, 4 is a backup power supply unit that performs backup when the voltage of the commercial power supply drops, and 6 is when low voltage is detected. This is an arithmetic control means for controlling the writing of predetermined data into the storage means 3.

In the normal state, power is supplied from the commercial power supply section 1, and the arithmetic control means 6 and peripheral circuits perform normal operations such as key manual power or communication, and the low voltage detection means 2
A normal pulse signal is inputted to the arithmetic control means 5 through the arithmetic and control means 5, and the backup power supply section 4 is always charged. Here, if the voltage of the commercial power supply drops due to a power outage or the like, or if the storage device is disconnected from the outlet and the power is cut off, the voltage drops, and the low voltage detection means 2 detects that the length as shown at the time of voltage drop. When a pulse signal exceeding a predetermined value is input to the arithmetic control means 6 and a drop in the current voltage is detected, the arithmetic control means 6 stores the data in the storage means 3 using the backup power supply unit 4 according to the writing procedure of the storage means 3. Write the required data.

Problems to be Solved by the Invention In such a conventional configuration, data is written into the storage means 3 every time a pulse signal exceeding a predetermined value is output from the low voltage detection means 2 and a drop in the power supply voltage is detected. . However, if the signal output from the low voltage detection means 2 is unstable, all the devices will not necessarily stop immediately, and data writing control will be performed many times, but the backup power supply section 4
The arithmetic control means 5 and the storage means 3 operate at a low voltage level due to insufficient charging.

Particularly when the storage means 3 is a non-volatile memory, there is a problem that data may not be written correctly due to strict voltage level requirements.

The present invention solves these problems, and aims to provide a backup storage device for electrical equipment that can reliably write data to the storage means even when a voltage drop is detected.

Means for Solving the Problems In order to achieve this object, the backup storage device for electrical equipment of the present invention includes a backup power supply unit that charges from a commercial power supply, and a low voltage unit that detects a voltage drop in the commercial power supply. a voltage detection means; a timekeeping means for measuring the time during which the low voltage detection means does not detect a voltage drop of the commercial power supply;
a storage means for storing predetermined data; and a storage means for storing predetermined data in the storage means only when the time measured by the timer means is longer than the charging time of the backup power supply section when the voltage drop of the commercial power source is detected by the low voltage detection means. The configuration includes arithmetic control means for controlling writing.

Effects of the present invention With the above-described configuration, when a low voltage is detected by the -degree low voltage detection means, the time period during which a drop in power supply voltage is not detected, which is measured by the clock means, is written in the backup power supply section and controlled. The arithmetic and control means does not perform writing control on the storage means unless the charging time has exceeded enough to charge the battery sufficiently, and performs write control if sufficient charging has been performed. Therefore, there is no possibility that writing of predetermined data into the storage means will fail due to a drop in the voltage level of the backup power supply section.

Example Embodiments of the present invention will be described below with reference to FIG.

FIG. 1 is a configuration diagram showing an embodiment of the present invention, in which 6 is a commercial power supply section, 7 is a low voltage detection means for detecting a drop in the voltage of the commercial power supply, and 8 is a section for storing predetermined data. Storage means consisting of non-volatile memory etc. 9 is low voltage detection means 7
When a low voltage is detected, an arithmetic control means controls the writing of predetermined data into the storage means 8, and 1o is a backup power supply unit that performs backup when the power supply voltage drops, and is charged by a commercial power supply. Reference numeral 11 denotes a timer for measuring the time during which the low voltage detection means 7 does not detect a voltage drop in the commercial power supply, and when the commercial power is in a normal state, a low voltage detection pulse signal is inputted as shown in FIG.

With the above configuration, if the voltage of commercial power drops due to a power outage or the like, or if the storage device connected to the power line via the outlet is disconnected from the outlet and the power is cut off, causing the voltage to drop, the low voltage detection means detects this. Detected at 7. As shown in FIG. 3, when a pulse signal in which the length of the measured value Tb of the voltage drop time exceeds a predetermined value TB (power failure detection pulse width time) is input to the calculation control means 9, the calculation control The means 9 inputs the respective sums of the clock times a measured by the clock means 11, and if this exceeds the time required for charging the backup power supply section 10 with the power necessary for writing in the storage means 8 (the storage means (if the required voltage level is higher than the required voltage level), data to be stored and held such as setting conditions (for example, ONE or OFF state, etc.) is written into the storage means 8 according to the writing procedure according to the charging power. If the low voltage detection means 7 again detects that the power supply voltage has not decreased, the time measurement means 11 starts anew to measure time a other than the pulse signal section shown in FIG. 3. Contrary to the above, if the charging time has not been exceeded, the data is not written to the storage means 8, but the low voltage detection means 7 waits until the low voltage detection means 7 no longer detects a drop in the power supply voltage, and from that time, the time measurement means 11 starts a new measurement in the same way. A flowchart of the operation of this embodiment as described above is shown in FIG. 4. Here, TA is the charging time of the backup power supply section, TB is the power failure detection pulse width time, T is the measured value of the time when the voltage is not decreasing, and Tb is the measured value of the time when the voltage is decreasing.

Effects of the Invention As described above, according to the device of the present invention, even when the power supply drops from an unstable state, after a -degree write is performed, if the power supply state in which low voltage is not detected continues for a predetermined period of time, the re-write is performed. Do not do this. Therefore, there is no need to provide a special means to determine whether the backup power supply is sufficiently charged.
It has an excellent feature of not having the conventional problem of writing control to the storage means over and over again every time a low voltage is detected, and writing fails due to a drop in the voltage level of the Quanop power supply. There is.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the device of the present invention, and FIG.
The figure shows the relationship between the power supply waveform and the low voltage detection signal, Figure 3 shows the relationship between the power supply waveform, the low voltage detection signal, the charge level and the required voltage level of the storage means, and Figure 4 shows the relationship between the power supply waveform, the low voltage detection signal, the charge level and the required voltage level of the storage means. FIG. 6 is a block diagram showing a conventional example. 7... Low voltage detection means, 8... Memory means, 9... Arithmetic control means, 10... Backup power supply unit, 11...・Timekeeping means. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 Figure 4

Claims (2)

[Claims] (1) A backup power supply section that performs charging using a commercial power supply, a low voltage detection means that detects a drop in the voltage of the commercial power supply, and a period during which the low voltage detection means does not detect a voltage drop of the commercial power supply. a clocking means for measuring, a storage means for storing predetermined data, and when a voltage drop of the commercial power supply is detected by the low voltage detection means, when the time measured by the clocking means is longer than the charging time of the backup power supply unit; and arithmetic control means for controlling writing of predetermined data into the storage means. (2) A backup storage device for electrical equipment according to claim 1, which uses nonvolatile memory as the storage means.