JPH0667352B2 - Coffee heater - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a coffee brewer for crushing coffee beans and automatically extracting coffee.

2. Description of the Related Art Conventionally, this type of coffee brewer has a circuit configuration as shown in FIG. That is, in this FIG.
Reference numeral 1 is an AC power supply, 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 heater 3 is connected to the AC power source 1 via the contact 2a of the mainspring 2 and the thermostat 4, and the motor 5 is connected to the mainspring 2
It is connected to the AC power supply 1 via the contact 2b. A timing chart of the contacts 2a and 2b of the mainspring timer 2 is shown in FIG. In FIG. 3, the timer knob is set according to the amount of coffee beans, and when the start button is pressed, the mainspring timer 2 starts to operate, the contact 2b is turned on for the set time T, and then the contact 2a is turned on. . When the timer knob is turned off, both contacts 2a and 2b are turned off.

With 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 set time T
Only the contact 2b is turned on and the motor 5 is rotated to crush the coffee beans. Then, when the time T elapses, the mainspring timer 2
Since the contact 2b of 1 is turned off and the contact 2a is turned on, the motor 5 is stopped and the heater 3 is energized to produce hot water. The hot water is then sprinkled on the ground coffee beans to extract the coffee, and the coffee extracted by the thermostat 4 is kept warm.

Problems to be Solved by the Invention In such a conventional configuration, since it is necessary to press the start button after adjusting the setting of the mainspring timer 2 according to the amount of coffee beans, there is a variation in the setting of the mainspring timer 2. There was a problem that the coffee taste was not stable due to variations in how to grind the beans, and two-step operations of adjusting the setting of the mainspring timer 2 and the operation of the start button were required, resulting in poor usability.

The present invention solves such a problem, and with a simple configuration, automatically detects the completion of crushing of coffee beans, and automatically switches the energization of the heater to determine how to grind the coffee beans. An object of the present invention is to provide a coffee brewer having a stable taste, a stable operation, a simple operation and a good usability.

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 heat of the motor, a current detecting means for detecting a current flowing through the motor, a comparator having a voltage signal from the current detecting means as one input and a reference voltage as the other input, and a comparator for this comparator. It is configured by a first energization control element that stops energization to the motor by output and a second energization control element that starts energization to the heater.

Effect According to this configuration, by energizing the motor to rotate the cutter, the coffee beans are crushed, and as the coffee beans are crushed, the load on the motor is reduced and at the same time the current flowing through the motor is reduced. It is possible to automatically determine the completion of coffee bean crushing by detecting the phenomenon that the coffee bean is crushed and to automatically switch the energization from the motor to the heater. Since the operation only requires one push of the start button, it is extremely simple, 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 FIG. In FIG. 1, the same parts as those in FIG. 2 shown in the conventional example are designated by the same reference numerals, and the description thereof will be omitted.
In FIG. 1, reference numeral 6 is a relay contact, and the heater 3 is connected to the AC power supply 1 via the relay contact 6 and the thermostat 4. Reference numeral 7 is a bidirectional thyristor (hereinafter referred to as a triac), and the motor 5 is connected to the AC power supply 1 via the triac 7. 8 is a motor 5
The current detecting means 8 is a current detecting means for detecting the current flowing through the current transformer 8. The current detecting means 8 is composed of a current transformer 9 for converting the amount of current flowing through the motor 5 into a voltage, a diode bridge 10 and a smoothing capacitor 11. Reference numeral 12 is a comparator having an open collector output. The input of the comparator 12 is the voltage signal from the current detecting means 8 and the reference voltage divided by the resistor. The output of the comparator 12 causes the triac 7 to operate. Drive it and turn the motor 5 on and off. Further, the output of the comparator 12 operates the relay coil 16 via the inverter 14 and the transistor 15 of the switch control circuit 13 to turn the relay contact 6 on and off. 17
Is a start switch connected in parallel with the output of the comparator 12, and 18 is a DC power supply for operating the above-mentioned circuit.

Next, the operation of the above configuration will be described. First, when the start switch 17 is turned on, the transistor 15
Becomes 0FF, and at the same time the relay contact 6 is turned off, the triac 7 is turned on and a current flows through the motor 5. When a current flows through the motor 5, a voltage corresponding to the amount of current flowing through the motor 5 is generated at the output of the current detection means 8 and the output of the comparator 12 is turned on. At this point, the start switch 17 is turned off. This ON state is also maintained. When the coffee beans are crushed and the load is reduced, the amount of current flowing through the motor 5 is reduced, the output voltage of the current detection means 8 is reduced, and finally the output of the comparator 12 is turned off and the triac 7 is turned off. Becomes 0FF. As a result, no current flows through the motor 5, and at the same time, the relay coil 16 is operated to turn on the relay contact 6. As a result, an electric current starts flowing through the heater 3, and hot water for extracting coffee is generated.

As described above, according to the present invention, by energizing the motor and rotating the cutter, the coffee beans are ground, and the load on the motor is reduced as the coffee beans are ground, and at the same time the motor is Detecting the phenomenon that the current flowing to the coffee is decreasing, it automatically determines the completion of crushing the coffee beans and automatically switches the energization from the motor to the heater. In addition to being able to stabilize the coffee machine, regardless of the amount of coffee beans, it can be operated by pressing one start button, which makes it extremely easy to use, and as a result, a coffee brewer that is easy to use and has a stable taste What can be provided.

[Brief description of drawings]

1 is an electric circuit diagram of a coffee brewer showing an embodiment of the present invention, FIG. 2 is an electric circuit diagram of a conventional coffee brewer,
FIG. 3 is a timing chart of the coffee brewer. 3 ... Heater, 5 ... Motor, 6 ... Relay contact, 7 ...
... Bidirectional thyristor (triac), 8 ... current detecting means, 9 ... current transformer, 12 ... comparator, 1
3 ... Switch control circuit, 16 ... Relay coil.

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 comparator having the voltage signal from the current detection means as one input and the reference voltage as the other input, and the first energization control element and the heater for stopping energization of the motor by the output of the comparator. A coffee brewer constituted by a second energization control element for starting energization of.