JPH0520264Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an electric pot, and particularly to an electric pot that operates normally even if a power outage occurs during use.

(Prior Art) Recently, electric water pots have been developed that have a built-in microcomputer that controls the water boiling and warming operations according to a built-in program, and also has a reservation timer that is activated by a timer set switch and starts boiling water after a predetermined period of time has elapsed. , for example, was proposed in Japanese Patent Application No. 16407/1982 (see Japanese Patent Application Laid-open No. 172917/1983), and has been put into practical use.

In this electric pot, when the reservation timer set switch SW is pressed, the timer operation is started regardless of its operating state, the control means stops the heating means, and after the preset time on the reservation timer has elapsed,
In response to the signal from the reservation timer, the control means activates the heating means to enter boiling operation, and when the temperature detected by the liquid temperature sensor that detects the liquid temperature reaches the heat retention reference temperature, the power supply to the heat retention heater is stopped. This is done by stopping the power supply to the water heater when the temperature detected by the steam temperature sensor that detects the steam temperature reaches the boiling reference temperature.

(Problem to be solved by the invention) However, in the electric pot, even if there is an instantaneous power outage while the reservation timer is operating, the memory that stores the current time will be lost due to the length of the power outage, and the timer operation will be interrupted. There is a problem in that the water may not be boiling when it stops and the initially set time has elapsed. Additionally, the system cancels the halt mode at the rising edge of the zero-cross pulse, completes a series of processes within a predetermined time, and then enters the halt mode again to standby. However, when a power outage occurs, the zero-cross pulse does not come in, so the halt mode is disabled. There was an inconvenience that the mode could not be released.

(Means for Solving the Problems) As a means for solving the problems, the present invention provides a heating means 2 for heating the liquid in the container 1, and a switching means for turning the heating means 2 on and off. In the electric pot, the electric pot has a drive circuit 3 that controls the power supply, and a control means 4 that controls the drive circuit 3 according to a built-in program.
a power failure detection timer 5 which is activated immediately before the controller enters the halt mode and outputs a signal to release the control means 4 from the halt mode after a time longer than the zero-cross pulse interval; the contents of the data memory 6; and the contents of the program memory 7. An operation mode setting means 8 is provided for selecting an operation mode before a power outage or a power-on mode by comparing a part of the power supply with the power supply.

(Function) In the present invention, the control means 4 is released from the halt mode by the rising edge of the zero-cross pulse and enters the run mode, completes a series of processes within a certain period of time (for example, a half-wave span in 60Hz regions), and returns to the halt mode. mode and waits until the next zero-crossing pulse enters, but before entering halt mode, a power failure detection timer is started and a predetermined time longer than the zero-crossing pulse interval, e.g.
If there is a power failure that does not cause a zero-cross pulse to enter the control means within 32 ms, the timer for power failure detection times up, and the control means is released from the halt mode by that signal.

Next, when the power is restored and the run mode is entered by a zero-cross pulse, the data stored in the data memory is compared with part of the contents of the program memory, and if the two match, the operating mode is set. means continue the operating mode before the power outage;
If they do not match, the system switches to power-on mode and starts boiling water.

(Embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

1 and 2 show a control device for an electric pot according to the present invention, in which 1 is a container, 2 is a heating means, and 2a
1 is a water heater, 2b is a heat retention heater, 3 is a drive circuit, 3a is a relay drive circuit, 3b is a triac drive circuit, 13 is a water heater that turns on the water heater 2a.
A relay constituting a switching means for turning off, 1
4 is a photo try-out coupler, Q ₁ and Q ₂ are transistors, R ₁ to _{R 17} are resistors, C is a capacitor,
Reference numeral 15 denotes a triac constituting switching means for turning on and off the heat-retaining heater 2b, and the relay drive circuit 3a and the triac drive circuit 3b are controlled by the microcomputer 11.

The control device is mainly a microcomputer 1.
It consists of 1. Microcomputer 11
consists of a central processing unit (CPU), data memory (RAM), program memory (ROM), timer, and input/output ports (I/O ports).
a vapor temperature sensor 16 that detects boiling of the liquid;
A liquid temperature sensor 17 that detects the liquid temperature, a water level detection electrode 18 that sets the minimum amount of water and detects the water level in the container 1, a power-on reset circuit 20, a reboiling switch SW ₁ , and a timer set. It is equipped with a switch SW ₂ and light emitting diodes LED ₁ to _{LED 5} that display the operating status. The power outage detection timer 5 is repeatedly started and stopped at intervals longer than the zero-cross pulse interval.

When using the electric pot having the above configuration, when the power is turned on, a high-level active reset signal is input from the power-on reset circuit 20 to the reset terminal of the microcomputer 11, and the microcomputer 11 is reset. That is,
In this power-on mode, first, the inside of the microcomputer is initialized (step 1), and output settings and keywords for power outage are written (step 2).

After writing the power outage keyword, it is determined whether a power outage has been detected (step 3), and if there is no power outage, normal processing is performed according to the program written in the program memory (ROM), that is, a series of operations from boiling water to keeping it warm. The normal process for performing the process is performed (step 4).

The CPU is activated by the signal from the power failure detection timer 5.
When the system is released from the halt mode, it is determined that there has been a power outage, and the process moves to step 100. When the power is restored, the system first determines whether or not it has been reset based on the signal from the power-on reset circuit (step 100). Then, a determination is made as to whether or not the system has recovered by using a zero-cross pulse (step 101).

When it is determined that the power has recovered due to the zero-cross pulse (step 101), the contents of the data memory (RAM) are compared and contrasted with part of the contents of the program memory (ROM) (step 102), and if they match, the contents of the data memory (RAM) are compared with part of the contents of the program memory (ROM). The mode continues, and if they do not match, the mode shifts to the power-on mode and a series of processes from boiling operation to heat retention operation are performed.

In addition, if it is restored by a signal from the power-on reset circuit, it will move to power-on mode and
Since it is initialized, it performs a series of processes from boiling operation to warming operation.

(Effects of the invention) As is clear from the above explanation, when there is a power outage, the electric pot according to the invention shifts to the power-on mode or the operation mode immediately before the power outage depending on the duration of the power outage, and resumes each operation. As a result, even if the memory storing the timer time is lost due to an unexpected power outage, the water can be reliably heated.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an electric pot according to the present invention, FIG. 2 is a circuit diagram of its control device, and FIG. 3 is a flowchart of its essential parts. DESCRIPTION OF SYMBOLS 1... Container, 2... Heating means, 2a... Water boiling heater, 2b... Heat retention heater, 3... Drive circuit, 3a... Relay drive circuit, 3b... Triac drive circuit, 4... Control means, 5 ... timer for power failure detection, 6 ... data memory, 7 ... program memory, 8 ... operation mode setting means, 13 ...
... Relay (switching means), 15 ... Triack (switching means), 20 ... Power-on reset circuit.

Claims (1)

[Scope of utility model registration request] An electric pot comprising a heating means for heating a liquid in a container, a driving circuit for driving a switching means for turning on and off the heating means, and a control means for controlling the driving circuit according to a built-in program. a power outage detection timer that is activated immediately before the control means enters the halt mode and outputs a signal to release the control means from the halt mode after a time longer than the zero-cross pulse interval; An electric pot characterized by having an operation mode setting means for selecting an operation mode before a power outage or a power-on mode by comparing a part of the contents.