JPS6341575B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is configured to boil water using a heater as a heat source and supply the water to a coffee liquid extraction case containing coffee powder, particularly during a predetermined waiting period. This invention relates to a coffee brewer that automatically starts energizing the heater when the temperature switch is turned off. To provide a coffee extractor which can surely prevent malfunction of its ringer and accurately notify the completion time of extracting coffee liquid.

An embodiment in which the present invention is applied to a coffee maker having both a hot water supply (drip) mechanism and a mill mechanism will be described below with reference to the drawings.

1 is a lid switch, which is configured to be turned on only when the lid of the case (none of which is shown), which is used for both grinding coffee beans and extracting coffee liquid, is properly set in a predetermined position. The lid switch 1, the heater 2, the bimetal switch 3 as a temperature switch, and the output switch 4a of a heater drive circuit 4 (described later) as a drive switch are connected in series in this order between both output terminals 5a and 5b of an AC power source 5. The heater circuit A is constituted by these series circuits. Then, a series circuit of a mill motor 6 and an output switch 7a of a motor drive circuit 7 to be described later is connected in parallel with the series circuit of the heater 2, bimetal switch 3, and output switch 4a. In this case, the motor 6 is attached to a mill mechanism (not shown), and the mill mechanism has a cutter rotated by the motor 6 in the case, and the coffee beans stored in the case are rotated by the rotation of the cutter. to produce coffee powder. Further, the heater 2 is attached to a hot water supply mechanism (not shown), and the hot water supply mechanism converts water supplied from a water storage tank to the heater into hot water using the heater 2, and lowers the boiling pressure of the hot water thus generated. The coffee liquid is extracted by supplying the coffee powder into the case containing the coffee powder. Furthermore, the bimetallic switch 3 is of a normally closed type that is turned off when the heater exceeds a predetermined temperature. on the other hand,
Reference numeral 8 denotes a DC power supply circuit for rectifying the output of the AC power supply 5 and providing it as a power source for a control circuit 9, which will be described later. In the figure, only the low potential side (zero potential side) output line 8a is shown among the output lines. It shows. 10
is a detection circuit for detecting the state of the heater circuit A, which will be described below. That is, the common connection point of the heater 2 and bimetal switch 3 in the heater circuit A constitutes a signal extraction point 11, and this signal extraction point 11 is connected to the base of the PNP type transistor 13 in the detection circuit 10 via a resistor 12. Connect to. The emitter of the transistor 13 is connected to the output terminal 5b of the AC power supply 5, the collector of the transistor 13 is connected to the low potential side output line 8a of the DC power supply circuit 8 via the resistor 14, and the base of the transistor 13 is connected to the output terminal 5b of the AC power supply 5. - Connect a parallel circuit of a resistor 15 and a diode 16 between the emitters. Then, the collector of the transistor 13 forming the output terminal of the detection circuit 10 is connected to the line _L1 .
Connect to.

Now, the configuration of the control circuit 9 will be described below. In this case, most of the functions of the control circuit 9 can be obtained by a program of a microcomputer, but here, for convenience of explanation, a combination of block circuits will be described. It is shown with. That is,
A frequency divider 17 divides the frequency of the output of the AC power supply 5, and outputs a counting pulse Pc at a period of, for example, 1 Hz. Reference numeral 18 denotes a set switch that is turned on only in the manual operation state, and a high level signal is applied to one input terminal of the AND circuit 19 only when this switch is turned on. The other input terminal of the AND circuit 19 is connected to receive the counting pulse Pc, and therefore, the AND circuit 19 passes the counting pulse Pc only during the ON period of the set switch 18. For example, 20 is a hexadecimal up counter, which is the clock input terminal from the AND circuit 19.
It adds and counts the pulses input to CK and outputs the counted contents as a digital signal Sn. 21 is, for example, 3 consisting of a 7-segment light emitting diode, etc.
digit digital display, this is the digital signal
When Sn is received through the transfer gate 22, a numerical value (maximum 2 digits) corresponding to the digital signal Sn is displayed. The transfer gate 22 has a configuration that exhibits low impedance and allows the signal to pass only when a high level signal is input to its control terminal 22a, and the other transfer gates described below have the same configuration. be. 2
A storage circuit 3 stores a display information signal Sd of a predetermined mode, and the information signal Sd is input to the digital display 21 when the transfer gate 24 is in a conductive state. When the information signal Sd is input to the digital display 21, the digital display 21 displays, for example, "LId" as shown in FIG. On the other hand, 25 is a start switch that is turned on only in the manual operation state, and when this is turned on, a high level signal is given to one of the input terminals of the 3-input type AND circuit 26. 27
is also a stop switch that is only turned on during manual operation, and when it is turned on, the line
A high level signal is output to _L2 . 28 has its set input terminal S connected to the output terminal of the AND circuit 26, and its reset input terminal R connected to the line.
The output from the set output terminal Q of the R-S flip-flop connected to _L2 is given to one input terminal of the AND circuit 30 via the delay circuit 2, and to one input terminal of the other AND circuit 31. It has also become possible to directly provide
The other input terminal of the AND circuit 31 is connected to the line _L1 .
It is connected to. At this time, the delay circuit 29 is
The delay time is set to about 20 mS, for example. The delay circuit 29 is located downstream of the delay circuit 29.
The output terminal of the AND circuit 30 is connected to the control terminal 22a of the transfer gate 22 via an inverter 32, and is also directly connected to the control terminal 24a of the transfer gate 24. is AND
The transfer gate 24 is conductive when the circuit 30 outputs a low level signal, and the transfer gate 24 is conductive when the AND circuit 30 outputs a high level signal. 33 is an RS flip-flop whose set input terminal S is connected to the output terminal of the AND circuit 31 and whose reset input terminal R is connected to the line _L2 . is applied directly to the other input terminal of the AND circuit 30, and is applied directly to the monostable multivibrator 35 which outputs a high level signal for a short time when receiving a rising signal, and is also applied via a delay circuit 36 to the signal generating section. It is also applied to one input terminal of the AND circuit 37. 38 is a down counter having a preset function and a clear function. When a digital signal is input to its data input terminal D, this down counter presets a numerical value corresponding to the input digital signal, and also when a pulse is input to the clock input terminal CK. Each time it is input, it is subtracted from the above preset value, and the clear terminal is
The configuration is such that when a high level signal is input to CL, the count value is cleared to "0". moreover,
This down counter 38 is configured to output a high level signal only during a period when its count value is other than "0", and operate the motor drive circuit 7 by this high level signal. When operated in this manner, the output switch 7a is turned on. Also, down counter 3
8 data input terminal D is transfer gate 39
The clock input terminal CK is connected to the output terminal D of the up counter 20 through the AND circuit 40.
is connected to the output terminal of CL, and the clear input terminal CL
is connected to the line _L2 . and above
One input terminal of the AND circuit 40 is connected to receive the counting pulse Pc, and the other input terminal is connected to the output terminal P of the down counter 38. The control terminal 39a of the transfer gate 39 is connected to the monostable multivibrator 3.
It is connected to receive the output from 5. Further, the output terminal P of the down counter 38 is branched into two after passing through the inverter 41, and the output terminal P of the down counter 38 is branched into two branches to the AND circuit 2
It is connected to each input terminal of 6 and 37,
The remaining input terminals of the AND circuit 26 are connected to the inverter 4.
2 to the output terminal of the AND circuit 37. Further, the output terminal of the AND circuit 37 is connected to the AND circuit 4 which is a gate circuit via a delay circuit 43 which is a timer circuit with a delay time of about 10 ms, for example.
It is connected to one input terminal of 4, and this
The other input terminal of the AND circuit 44 is connected to the line _L1 . 45 is a D flip-flop whose data input terminal D is connected to a high level signal source 46, whose clear input terminal CL is connected to line _L2 , and whose clock input terminal CK is connected to the output terminal of AND circuit 44. . 47 is a monostable multivibrator that outputs a high level signal for a predetermined period in response to the rise of the output of the D flip-flop 45 to a high level signal; its output is sent to the AND circuit 49 via an inverter 48; The signal is applied to one input terminal and is also applied directly to the buzzer drive circuit 50. This buzzer drive circuit 50 causes a buzzer 51, which is a ringer for notifying completion of extraction of coffee liquid, to ring only during a period when a high level signal is input. On the other hand, the AND circuit 49 is connected to give its output to the heater drive circuit 4, and this heater drive circuit 4 is operated while the high level signal is being input to turn on the output switch 4a. This is a configuration that allows Note that the other input terminal of the AND circuit 49 is connected to the output terminal of the AND circuit 37.

Next, the operation of this embodiment having the above configuration will be explained. When producing coffee liquid, an amount of water corresponding to the desired number of people is supplied into the water storage tank of the hot water supply mechanism, and with the corresponding amount of coffee beans stored in the case, the lid is placed on the case. A bottle for storing coffee liquid is placed on the heater of the hot water supply mechanism. Then, in this state, coffee beans are first milled. In this case, when the set switch 18 is turned on and kept in the on state, the count pulse Pc from the frequency divider 17 is given to the up counter 20 via the AND circuit 19, which adds and counts the count pulse Pc. The content of the count is then output as a digital signal Sn. At this time,
As will be clear from the description below, since a low level signal is output from the AND circuit 30 and the transfer gate 22 is conductive, the digital display 21
starts to receive the digital signal Sn, so the digital display 21 shows the numerical values corresponding to the digital signal Sn as "0" → "1" → "2".
→ "3", etc. are displayed in increasing order, and the operator releases the ON operation of the set switch 18 when the display reaches the desired value, for example, "12". Such a set switch 18
When the ON operation is canceled, the high level signal is no longer input to the AND circuit 19, and the AND circuit 19 blocks passage of the counting pulse Pc, so the up counter 20 stops counting operation. The count value "12" which is the count result is stored, and the digital signal Sn corresponding to the count value "12" is output. Therefore, at this time, the digital display 21 continues to display "12". After this, when the start switch 25 is turned on, in this case, as will be understood from the description below, a high level signal is output from the inverters 41 and 42, so a high level signal is output from the AND circuit 26, and this high level signal is output from the AND circuit 26. The RS flip-flop 28 which receives the signal at its set input terminal S is set and outputs a high level signal from its set output terminal Q. However, in such a situation,
If the lid of the case is not properly set in the predetermined position, the lid switch 1 is turned off, and the output switch 4a is also turned off.
No base current is applied from the signal extraction point 11 to the base of the transistor 13, and the transistor 13 is in an off state. Therefore, a low level signal corresponding to the potential of the low potential side output line 8a of the DC power supply circuit 8 is continuously output to the line _L1 , and the AND circuit 31 continues to output the low level signal. present. Therefore, R-
The S flip-flop 33 does not receive a high level signal at its set input terminal S, maintains a reset state, and outputs a low level signal. As mentioned above, when the start switch 25 is turned on and a high level signal is output from the RS flip-flop 28,
The high level signal is delayed by the delay circuit 29 and then applied to one input terminal of an AND circuit 30, and the low level signal from the RS flip-flop 33 is applied to the other input terminal of the AND circuit 30. It is given after being inverted by 34. Therefore, high level signals are input to both input terminals of the AND circuit 30, and a high level signal is output from the AND circuit 30, which is applied to the gate terminal of the transfer gate 24. The transfer gate 24 becomes conductive. Then, the memory circuit 23
The information signal Sd from the lid is input to the digital display 21 and becomes displayed as "LId" (see FIG. 2), thereby informing that the lid is not properly set. Incidentally, when the start switch 25 is turned on with the lid not properly set, the monostable multivibrator 35 is driven because a high level signal is not output from the R-S flip-flop 33 as described above. Therefore, the transfer gate 39 maintains a non-conducting state. Therefore, a digital signal is input to the data input terminal D of the down counter 38.
Since Sn is not input, the down counter 38 is in its initial state, that is, its count value is "0".
Since the output switch 7a continues to output a low level signal, the output switch 7a is not turned on by the motor drive circuit 7, and the motor 6 is maintained in a non-energized state. That is, the milling operation will not be started unless the lid is properly set. On the other hand, when the case lid is properly set in the predetermined position, the lid switch 1 is on and the output switch 4a is off, so that every half wave period when the output terminal 5b side of the AC power source 5 is at a high level. A base current is supplied from the signal extraction point 11 to the transistor 13, and the transistor 13 is turned on periodically according to the frequency of the AC power supply 5. For this reason,
The line _L1 is a detection signal Sa which is an intermittent high level signal every time the transistor 13 is turned on.
is output. Therefore, if the lid is not properly set and the start switch 25 is turned on, and then the lid is reset normally based on the display "Ld" on the digital display 21 as described above, and the lid is When the start switch 25 is turned on in a normally set state, a high level signal is input to both input terminals of the AND circuit 31, and this AND circuit 31 outputs a high level signal, so that the flip-flop 33 is turned on. A high level signal is output from the set output terminal Q. Then, the monostable multivibrator 35 driven by this high level signal
outputs a high level signal for a short period of time to make the transfer gate 39 conductive, the digital signal Sn stored in the up counter 20 is applied to the data input terminal D of the down counter 38; digital signal
A numerical value "12" corresponding to Sn is preset, and a high level signal is output from the output terminal P to operate the motor drive circuit 7. This turns on the output switch 7a and energizes the motor 6, which rotates the cutter and starts grinding the coffee beans in the case. At the same time, a high level signal is applied to one input terminal of the AND circuit 40, and the counting pulse Pc applied to the other input terminal of the AND circuit 40 passes through it. The down counter 38, which receives the counting pulse Pc at its clock input terminal CK, starts a subtractive counting operation. Such a subtraction counting operation is started based on the preset value "12", and the counted value is "12" → "11" →
It will gradually decrease to "10"... and,
When the count value of the down counter 38 becomes "0",
Since a low level signal is output from the output terminal P instead of a high level signal, the motor drive circuit 7 is stopped and its output switch 7a is turned off, thereby cutting off the power to the motor 6 and making coffee. At the same time as the grinding of the beans is completed, the AND circuit 40
The input of the counting pulse Pc to the down counter 38 is stopped. However,
The count value of the down counter 38 changes from “12” to “0”
Since the output period of the counting pulse Pc is 1 Hz, the time it takes to reach 1 is 12 seconds, and therefore, the coffee bean grinding time (mill time) as described above is controlled to 12 seconds. Incidentally, as mentioned above, the flip-flop 33
When a high level signal is output from the set output terminal Q of
4 and input to the AND circuit 30, the AND circuit 30 outputs a low level signal. Therefore, the transfer gate 22 becomes conductive and the digital display 21 receives the digital signal Sn from the up counter 20. Corresponding number "12"
will be displayed. Also, before the start switch 25 is turned on, the R-
Since the S flip-flop 28 outputs a low level signal, this low level signal is sent to the delay circuit 2.
The AND circuit 30 which receives the signal through the signal line 9 outputs a low level signal as described above. Further, the delay circuit 29 is provided to compensate for the fact that the detection signal Sa output to the line _L1 is an intermittent high level signal.

Now, when the milling operation is completed as described above, the process automatically shifts to the dripping operation, which is the extraction operation. That is, when the down counter 38 outputs a low level signal and the milling operation is completed, the inverter 41 that has received the low level signal starts outputting a high level signal, and this high level signal is
It is applied to one input terminal of the AND circuit 37.
At this time, the other input terminal of the AND circuit 37 has
At the time when the flip-flop 33 outputs a high-level signal (in other words, when the milling operation is started), the high-level signal is input through the delay circuit 36, and therefore, as a result, the AND
At the same time as the milling operation, which is a predetermined waiting period, ends, the circuit 37 outputs an operation command signal Sb consisting of a high level signal instead of the previous low level signal, and this operation command signal Sb is sent to the delay circuit 4.
3 to one input terminal of the AND circuit 44, and also directly to the other input terminal of the AND circuit 49. In this case, the moment the operation command signal Sb is output from the AND circuit 37, the AND circuit 4
4 (the input terminal connected to the delay circuit 43) is given a low level signal and the corresponding
Since the AND circuit 44 is outputting a low level signal, the D flip-flop 45 is in an initial state (clear state) and outputting a low level signal from its output terminal Q, and the monostable multivibrator 47 is also in a non-driven state. In this case, a low level signal is output, and the inverter 48 that receives this outputs a high level signal. Therefore, the operation command signal Sb is received from the AND circuit 37 at the moment it is output.
Since the AND circuit 49 outputs a high level signal,
The heater drive circuit 4 is operated and the output switch 4a is turned on.
is turned on, whereby the heater 2 is energized and generates heat. And, like this, output switch 4
When a is turned on, the base current is no longer supplied to the base of the transistor 13 from the signal extraction point 11 and the transistor 13 is turned off, so the detection signal Sa disappears and the line
A low level signal is now output to L ₁ ,
Therefore, a low level signal is applied to the input terminal of the AND circuit 44 connected to line _L1 . When the heater 2 is energized and generates heat as described above,
Water in the heater supplied from the water storage tank is heated by the heater 2 and turned into hot water, and the hot water thus generated is supplied into the case by its boiling pressure and extracted as coffee liquid, The extracted coffee liquid flows down and is stored in a bolt placed on the heater. When all the water in the water storage tank is consumed by such coffee liquid extraction or dripping operation, the temperature of the heater will rise rapidly due to no heat exchange between the heater and the water. Bimetal switch 3 that detected this
is turned off, the heater 2 is cut off, and the dripping operation is completed. When the dripping operation is completed as described above, that is, when the bimetal switch 3 is turned off, the base signal is again applied from the signal extraction point 11 to the base of the transistor 13, and the transistor 13 is turned on.
The detection signal Sa is again output to _L1 .
Then, the detection signal Sa and the operation command signal Sb are simultaneously input to both input terminals of the AND circuit 44, and the corresponding
Since the AND circuit 44 begins to output a high level signal, the D flip-flop 45 is triggered and outputs a high level signal, and in response, the monostable multivibrator 47 outputs a high level signal for a predetermined period. Become. Therefore, the buzzer drive circuit 50 is turned on for a predetermined period, and the buzzer 51 sounds during this period, thereby notifying the user that the dripping operation has been completed. Note that during the period when the buzzer 51 is ringing, that is, when the monostable multivibrator 47
During the period when a high level signal is being output from the inverter 48, the high level signal is inverted to a low level signal and inputted to the AND circuit 49, so that the AND circuit 49 outputs a low level signal. Heater drive circuit 4
operation is temporarily stopped. After the above-described dripping operation is completed, the bimetal switch 3 is intermittently turned on and off to control the heater 2 to be turned on and off, and the coffee liquid in the bottle is kept warm by the heater. To stop such heat retention, the stop switch 27 is turned on. Then, this on operation turns the line on.
By the high level signal output to _L2 , R-
S flip-flops 28, 33, down counter 38 and D flip-flop 45 are all reset or cleared, especially R-S flip-flop 3.
By resetting step 3, a low level signal is input to the AND circuit 37, so the operation command signal is
The output of Sb is stopped, and a low level signal is output from the AND circuit 49 at the subsequent stage, whereby the operation of the heater drive circuit 4 is stopped and the heater 2 is cut off, that is, heat retention is stopped. Furthermore, if the stop switch 27 is turned on during the above-described dripping operation, the heater 2 is similarly cut off and the dripping operation is stopped midway. Furthermore, when the stop switch 27 is turned on during mill operation, the count value of the down counter 38 is cleared to "0" and a low level signal is output from now on, so the motor drive circuit 7 is stopped. The motor 6 is cut off, and the mill operation is stopped midway.

By the way, the starting point of the dripping operation, that is, AND
From the time when the circuit 37 outputs the operation command signal Sb,
It is unavoidable that there is a slight delay time (several milliseconds when a relay is used in the heater drive circuit 4) until the output switch 4a of the heater drive circuit 4 is turned on. Therefore, assuming that the delay circuit 43 is not provided, the operation command signal Sb
At the moment when is output, the output switch 4a is still off and the detection signal Sa (intermittent high level signal) is output to the line _L1 , so the detection signal Sa is simultaneously output to both input terminals of the AND circuit 44. and the operation command signal Sb are input. Then, AND
A high level signal is output from the circuit 44, triggering the D flip-flop 45, and the buzzer 51 is triggered.
This results in a malfunction in which the alarm sounds inadvertently. Moreover, once the D flip-flop 45 is triggered, the clock input terminal
Even if a high level signal is input to CK, it remains in the same state, so when the drip operation is completed, the monostable multivibrator 47 is not driven, resulting in a serious problem that the buzzer 51 does not sound. evoked. In contrast, in the present embodiment, a delay circuit 43 is provided in the signal transmission path between the AND circuits 37 and 44, and this delay circuit 43
The delay time is determined by the operation command signal from the AND circuit 37.
The delay time is set to, for example, 10 ms, which is longer than the delay time from when Sb is output to when the output switch 4a is turned on and a low level signal is output to line _L1 . Therefore, at the time when the operation command signal Sb is output from the AND circuit 37, the detection signal Sa and the operation command signal are simultaneously applied to both input terminals of the AND circuit 44.
The situation in which Sb is inputted is prevented by the delay action of the delay circuit 43, thereby reliably preventing problems such as the above-mentioned malfunction from occurring.

It should be noted that the delay circuit 36 in the above embodiment operates at the start of the milling operation, that is, at the moment when the high level signal is output from the RS flip-flop 33.
This is provided to prevent a situation in which high level signals are input to both input terminals of the AND circuit 37 at the same time.

Further, in the above embodiment, the mill operation time is a standby period, and when this period has elapsed, the operation command signal Sb is output. It may also be applied when a timer device that outputs a signal is provided.

As is clear from the above description, the present invention is characterized in that water is heated to boiling water using a heater as a heat source and is supplied into a coffee liquid extraction case containing coffee grounds. A normally closed type temperature switch that is turned off when the temperature of the device exceeds a predetermined value, and a normally closed type temperature switch that is turned on after a predetermined waiting period has elapsed, and when the temperature switch and heater are turned on, the temperature switch and the heater are connected in series to the power source for extraction. A coffee brewer is provided with a detection circuit that outputs a detection signal only when at least one of the drive switches for starting the operation is off, and operates a buzzer for notifying completion of coffee liquid extraction based on the detection signal. This provides excellent effects in that malfunctions of the ringer can be reliably prevented and the timing of completion of extraction of coffee liquid can be accurately notified.

[Brief explanation of drawings]

FIG. 1 is an electrical configuration diagram showing one embodiment of the present invention, and FIG. 2 is a front view showing one state of a digital display in the same embodiment. In the figure, 2 is a heater, 3 is a bimetal switch (temperature switch), 4a is an output switch (drive switch), 5 is an AC power supply, 10 is a detection circuit, and 37 is a
AND circuit (signal generator), 43 is a delay circuit (timer circuit), 44 is an AND circuit (gate circuit), 51
is a buzzer.

Claims (1)

[Claims] 1 In a device that uses a heater as a heat source to boil water and supply it into a coffee liquid extraction case containing coffee powder,
a signal generator that outputs an operation command signal when a predetermined standby period has elapsed; a normally closed temperature switch that is turned off when the temperature of the heater exceeds a predetermined value; and a period for outputting the operation command signal. a drive switch that connects the temperature switch and the heater in series to a power source when the switch is turned on; and a drive switch that outputs a detection signal only when at least one of the drive switch and the temperature switch is turned off. a detection circuit; and a gate circuit that is connected to receive outputs from the signal generation section and the detection circuit and operates a buzzer for notifying completion of coffee liquid extraction when the operation command signal and the detection signal are simultaneously input. 1. A coffee brewer comprising: a timer circuit for delaying signal transmission by a predetermined period of time between the signal generator and the gate circuit.