JPH0669424B2 - Coffee heater - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a coffee brewer that grinds coffee beans and automatically extracts coffee.

2. Description of the Related Art A conventional coffee brewer of this type has a circuit configuration as shown in FIG. In FIG. 3, 1 is an AC power source, 2 is a mainspring timer having two contacts 2a and 2b,
3 is a heater, 4 is a thermostat mounted near the heater 3, and 5 is a motor for rotating a cutter for crushing coffee beans. The motor 3 is connected to the AC power supply 1 via the contact 2a of the mainspring 2 and the thermostat 4, and the motor 5 is connected to the AC power supply 1 via the contact 2b of the mainspring 2. Mainspring timer 2 here
FIG. 4 shows a timing chart of the contacts 2a and 2b. In FIG. 4, when the timer knob is set according to the amount of coffee beans and the start button is pressed, the mainspring timer 2
Starts to operate, and contact 2b turns on for the set time T
After that, the contact 2a is turned on. When the timer knob is turned off, both contacts 2a and 2b are turned off.

In the above configuration, when the timer knob of the mainspring timer 2 is set according to the amount of coffee beans and the start button is pressed, the mainspring timer 2 starts operating, and the contact 2b is turned on for the set time T and the motor 5 Rotates and crushes coffee beans. Then, when the time T elapses, the contact 2b of the mainspring timer 2 is turned off and the contact 2a is turned on, so that the motor 5 is stopped and the heater 3 is energized to produce hot water, and this hot water is ground coffee. Coffee was brewed on beans, and the coffee extracted by thermostat 4 was kept warm.

Problems to be Solved by the Invention In such a conventional configuration, depending on the amount of coffee beans,
Since the start button must be pressed after adjusting the settings for the mainspring timer 2, the variation in the settings for the mainspring timer 2 can cause variations in the coffee bean ground and the taste of the coffee cannot be stable, or the settings for the mainspring timer 2 can be different. In addition, there is a problem in that it is inconvenient because it requires a two-step operation of the start button.

The present invention solves such a problem, and with a simple configuration, automatically detects the completion of crushing of coffee beans and automates the switching of the power supply to the heater. An object of the present invention is to provide a coffee brewer which is stable and easy to operate and easy to use, and which has a stable taste and is easy to operate.

Means for Solving the Problems In order to solve the above problems, a coffee brewer according to the present invention comprises a motor for rotating a cutter for crushing coffee beans, generation of hot water for extracting coffee, and extracted coffee. A heater for keeping and heating the same, a current detecting means for detecting a current flowing through the motor, a change detecting means for detecting a time point when the output signal of the current detecting means ends the decreasing change, and a time for starting time measurement from the time point Measuring means, comparing means for comparing the time measured by the time measuring means with a predetermined time, a first energization control element for stopping energization of the motor by the output of the comparing means, and output of the comparing means. And a second energization control element for starting energization of the heater.

Effect According to the above configuration, the motor is energized to rotate the cutter, the rotation crushes the coffee beans, and as the coffee beans are crushed, the load on the motor is reduced and at the same time the current flowing to the motor is reduced. Then, by detecting the phenomenon that the current is stable during idling, it can automatically determine the completion of coffee bean crushing, and can automatically switch the power supply from the motor to the heater. In addition to being able to stabilize the coffee machine, it is extremely easy to operate because it only needs to press one start button, and as a result, it is possible to provide a coffee brewer that is easy to use and has a stable taste. .

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In FIG. 1, the same parts as those in FIG. 3 shown in the conventional example are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 1 shows a circuit diagram of a coffee brewer according to an embodiment of the present invention. Reference numeral 6 denotes a microcomputer, which is composed of a CPU, a ROM, a RAM, an input / output port and the like. There is. This is a so-called one-chip microcomputer. Reference numeral 7 is a relay contact, and coffee 3 is connected to the AC power supply 1 via the relay contact 7 and the thermostat 4, and a current is supplied to the relay coil 9 via the transistor 8 by a signal from the output port of the microcomputer 6. , Open / close the relay contact 7. 10 is a bidirectional thyristor (hereinafter referred to as TRIAC),
The motor 5 is connected to the AC power supply 1 via the triac 10 and is driven by the signal from the output port of the microcomputer 6 via the resistor 10a. 11 is a motor 5
The current detecting means 11 detects a current flowing through the current transformer 11. The current detecting means 11 is composed of a current transformer 12 for converting the amount of current flowing through the motor 5 into a voltage, a diode bridge 13, and a smoothing capacitor 14. Reference numeral 15 is an A / D converter, which converts the output signal of the current detecting means 11 into a digital signal and inputs it to the input port of the microcomputer 6. 16 is a start switch. This start switch 16
Has been input to the microcomputer 6 so as to determine whether or not it has been pressed. Reference numeral 17 is a DC power supply for operating the above-mentioned circuit.

Next, the operation of the above configuration will be described. FIG. 2 shows a flow chart stored in the ROM of the microcomputer 6, which will be described according to the procedure of the program shown in this flow chart. First, in step 1, it is determined whether or not the start switch 16 is pressed, and it is kept pressed until it is pressed. When it is determined that the start switch 16 is pressed, the motor 5 is energized in step 2, and the time To is measured in step 3. First, in step 4, it is determined whether the current of the motor 5 has changed, and if the current has changed, the process returns to step 3 and the time To is measured again. If the current of the motor 5 does not change in step 4, it is determined in step 5 whether the time To is 5 seconds or more. If the time To is 5 seconds or less, the process returns to step 4 and the time To is 5 seconds or more. Goes to step 6. Here, the energization of the motor 5 is stopped and the heater 3 is energized in step 7. Return to step 7 until the start switch 16 is pressed in step 8,
Continue to energize the heater 3. When the start switch 16 is pressed in step 8, the process returns to step 2.

As described above, according to the present invention, the energization of the motor is started to rotate the cutter, the coffee beans are ground by this rotation, and the load on the motor is reduced as the coffee beans are ground. At the same time, the phenomenon that the current flowing through the motor decreases and stabilizes with the current during idling is detected with a relative change amount, so even if the current during idling of the motor fluctuates due to voltage fluctuation, It is possible to automatically judge the completion of crushing coffee beans and automate the switching of energization from the motor to the heater, and as a result, it is possible to stabilize the grinding method of coffee beans,
The operation is extremely simple because you only have to press one start button, and as a result, it is easy to use,
In addition, it is possible to provide a coffee brewer with a stable taste and simple operation.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a coffee brewer showing an embodiment of the present invention, FIG. 2 is a flow chart showing an example of a program of the coffee brewer, and FIG. 3 is a circuit diagram of a conventional coffee brewer. FIG. 4 is a timing chart of a mainspring timer of the coffee brewer. 3 ... Heater, 5 ... Motor, 6 ... Microcomputer, 7 ... Relay contact, 8 ... Transistor, 9 ...
Relay coil, 10 ... Bidirectional thyristor (triac), 11 ... Current detection means, 12 ... Current transformer,
15 …… A / D converter, 16 …… Start switch.

Claims (1)

[Claims] 1. A motor for rotating a cutter for crushing coffee beans, a heater for generating hot water for extracting coffee and keeping the extracted coffee warm, and a current detecting means for detecting a current flowing through the motor. A change detecting means for detecting a time point when the output signal of the current detecting means ends the decreasing change, a time measuring means for starting time measurement from the time point, and a comparison for comparing a time measured by the time measuring means with a predetermined time. Means, a first energization control element for stopping energization of the motor by the output of the comparison means, and a second energization control element for starting energization of the heater by the output of the comparison means Water heater.