JPH0159634B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a temperature control circuit for a hot water tank for supplying hot water used in a vending machine that sells coffee or the like by injecting hot water into powdered coffee.

Conventional technology Generally speaking, vending machines that supply hot water for coffee, cocoa, ramen noodles, etc. must stop selling once the water temperature drops below a predetermined temperature (63°C) due to issues with the Food Sanitation Act. However, as long as the temperature does not drop below 63°C, It is designed to maintain the set temperature almost all day long.

Furthermore, as is known from Japanese Patent Laid-Open No. 51-52895, vending machines that sell alcoholic beverages are configured to use a timer to stop night sales after 11 p.m. However, even if night sales are canceled, the temperature inside the warehouse is maintained at a predetermined set temperature.

Problems to be Solved by the Invention As described above, conventional vending machines are configured to maintain a predetermined vending temperature set by a temperature setting circuit all day long, and the number of sales at night is significantly reduced. The temperature is maintained at the selling temperature even when the selling operation is not performed, which has the disadvantage that power saving cannot be achieved.

The present invention is intended to solve the above-mentioned conventional problems, and aims to achieve power saving while clearing the restrictions under the Food Sanitation Act.

Means for Solving the Problems To achieve this object, a hot water tank temperature control circuit for a vending machine according to the present invention includes: a temperature detection circuit for detecting the temperature of the hot water tank; a heater for heating the hot water tank; a first temperature setting circuit that sets the maintenance temperature of the hot water tank maintained by heating the heater; and a first temperature setting circuit that sets the temperature of the hot water tank to a temperature that is lower than the set temperature of the first temperature setting circuit and higher than the prescribed temperature under the Food Sanitation Act. a second temperature setting circuit for maintaining the temperature, a switch circuit for controlling energization of the heater to the temperature set by the first or second temperature setting circuit, and a switch circuit for controlling the energization of the heater at the temperature set by the first or second temperature setting circuit; a switch for switching from the setting by the first temperature setting circuit to the setting by the second temperature setting circuit, and a third temperature setting switch set to a temperature between the first temperature setting circuit and the second temperature setting circuit. temperature setting circuit, and the hot water tank is connected to the third temperature setting circuit.
a stop circuit that stops the vending operation and stops hot water supply from the hot water tank when the temperature falls below the set temperature of the temperature setting circuit, and a fourth temperature setting circuit that is set to a temperature lower than the specified temperature under the Food Sanitation Act; The system is equipped with a stop circuit that stops the sales operation when the temperature of the hot water tank falls below the set temperature of the fourth temperature setting circuit, and a reset switch that cancels the sales stop operation by this stop circuit.

Effect With this configuration, when the number of sales set by the 24-hour timer becomes extremely low, such as at night, the setting by the first temperature setting circuit changes to the setting by the second temperature setting circuit. switching,
The water temperature is maintained at a low temperature set by the second temperature setting circuit, and when the water temperature drops below the set temperature of the third temperature setting circuit, a stop circuit is activated to stop the vending machine from selling. do. In addition, if the temperature inside the hot water tank drops below the set temperature of the fourth temperature setting circuit due to a malfunction, etc., a stop circuit is activated to stop the vending machine from operating and prevent further sales, which is required under the Food Sanitation Act. can solve the problem.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

In the figure, 1 is a heater that heats a hot water tank. 2 is a temperature detection circuit that detects the water temperature or wall temperature of the hot water tank. This temperature detection circuit 2
is thermistor TH, resistor R ₁ , R ₂ , R ₃ , amplifier 3
It is composed of 4 is a 24 hour timer. A relay 5 has a switch 5' for switching the output of the amplifier 3 to amplifiers 6 and 7. This relay 5 is operated by the 24-hour timer 4, for example, from 11:00 p.m. to 7:00 the next day.
Accordingly, the amplifier 6 is switched to the amplifier 7. The gain of the amplifier 6 is determined by resistors R ₄ and R ₅ , and the gain of the amplifier 7 is determined by resistors R ₆ and R ₇ . A first temperature setting circuit 8 is formed by the amplifier 6 and resistors R ₄ and R ₅ , and a second temperature setting circuit 9 is formed by the amplifier 7 and resistors R ₆ and R ₇ . Further, the outputs of the amplifiers 6 and 7 are connected to the base of a transistor 10, and the emitter of this transistor 10 is connected to a capacitor 11. 12 is PUT, which changes the voltage across the Zener diode 13 from the gate potential determined by resistors R ₈ and R ₉ to the potential of the anode connected to the emitter side of the capacitor 11, which is charged by the emitter current of the transistor 10. It generates a pulse when the value increases by a certain value. This pulse is heated by the transformer 14 and applied to the gate of the triac 15 via the resistor _R38 , and the triac 15 is turned on to control the energization of the heater 1. A diode 16 is provided on the secondary side of the transformer 14 to prevent current from flowing backward from the heater circuit connected to the AC power source. 17 is a diode 18, 19, 2
0,21, the temperature detection circuit 2 is a rectifier circuit;
A low voltage is applied to the first and second temperature setting circuits 8, 9, the transistor 10, etc. 22 is a third temperature setting circuit that receives the input potential of the temperature detection circuit 2 and detects whether the temperature is higher than the set temperature;
and resistors R ₁₁ and R ₁₂ . and,
A relay 24 is connected to the output side of the third temperature setting circuit 22, and a switch 24' of this relay 24 is a solenoid valve 2 that prohibits the supply of hot water from the hot water tank.
5 and relay 26 for refusing to accept coins in a vending machine
is controlled. This relay 24 and its switch 24' constitute a stop circuit 36 that controls the solenoid valve 25 and the relay 26.

The first temperature setting circuit 8 sets resistors R ₄ and R ₅ to change the voltage applied to the heater 1 to maintain a substantially constant temperature, and is set to a temperature of 90°C. ing. Further, the second temperature setting circuit 9 is set to maintain the temperature at 68° C. by resistors R ₆ and R ₇ .

Furthermore, the third temperature setting circuit 22 is a resistor.
When R ₁₁ and R ₁₂ become below 85℃, the relay 2
4 is set to operate.

A fourth temperature setting circuit 27 receives the input potential of the temperature detection circuit 2 and detects whether the temperature is higher than the set temperature, and is composed of an amplifier 28 and resistors R ₁₃ and R ₁₄ .

This fourth temperature setting circuit 27 is set to output an output at 63° C. or lower. 29 is R-
The output of the amplifier 28 is input to the R terminal of the S-type flip-flop. In addition, a capacitor 3 is connected to the S terminal via a reset switch 30.
NOT circuit 32 from the middle of the series circuit of 1 and resistor R ₁₅
connected via. Further, the output of the flip-flop 29 and the output of the amplifier 28 are input to a NAND circuit 33. The output of this NAND circuit 33 operates a relay 34, and a switch 34' of this relay 34 stops power supply to the heater 1. The relay 34, switch 34', flip-flop 29 and reset switch 30 constitute a stop circuit 37 for stopping the power supply. Also,
35 is transistor 7, capacitor 11, PUT
12, a transformer 14, a triac 15, a diode 16, and the like.

The operation of the hot water tank temperature setting circuit of the vending machine constructed as described above will be explained below with reference to the timing chart in FIG.

First of all, since the R-S flip-flop 29 has an output from the terminal Q and also has an output from the amplifier 28 of the fourth temperature setting circuit 27,
The NAND circuit 33 has no output and the relay 34 does not operate. As a result, the power supply to the heater 1 is cut off by the switch 34' of the relay 34. Therefore, by manually pressing the reset switch 30, input is given to the NOT circuit 32,
The S terminal of flip-flop 29 becomes “0”,
The output Q terminal also becomes "0". Therefore, NAND
Circuit 33 outputs an output to operate relay 34.

This initial state is when water is first poured into the hot water tank.

As a result, the switch 34' is closed and the first temperature setting circuit 8 by the temperature detection circuit 2 is below 90°C, so there is an output from the amplifier 6, and the switch circuit 35 is connected to the capacitor by the transistor 10.
1 is charged, and then a pulse is generated from PUT12. This pulse, after being heated by the transformer 14, causes the triax 15 to conduct, causing current to flow through the heater 1 (as shown by the voltage supplied to the heater in FIG. 2).
In this operation, even if the switch 5' is switched by the timer 4, the second temperature setting circuit 9 will output from the amplifier 7 when the temperature is below 63°C, so no matter which temperature setting circuit 8 or 9 it is on, water will not flow. It will heat up. In addition, energization to heater 1 is carried out by triax 15.
The applied voltage is adjusted by controlling the conduction angle of the In further explaining the operation, it is assumed for convenience that the switch 5' is located on the first temperature setting circuit 8 side. Then, the third temperature setting circuit 22
When a temperature of 85°C or higher is detected, the relay 24 operates and the switch 24' closes the solenoid valve 25 and the relay 2.
6 to be operated and made available for sale. Furthermore, when the water in the hot water tank is heated by the heater 1 and the first temperature setting circuit 8 detects 90°C, the output from the first temperature setting circuit 8 disappears, and as a result, the pulse from the PUT 12 disappears. As a result, the triax 15 becomes non-conductive, and the power supply to the heater 1 is cut off. When the temperature of the hot water drops or water is newly supplied and becomes lukewarm, the first temperature setting circuit 8 detects 90°C or less, outputs an output, turns on the transistor 10, and starts heating in the same way as the initial heating described above. When the heater 1 is activated, the heater 1 is energized. Also, when water is supplied or the heater 1 is disconnected and the temperature of the hot water drops below 85°C, the relay 24 turns off and refuses to accept coins through the solenoid valve 25 and relay 26, stopping the vending machine from operating. . but,
At this time, if the temperature is lowered due to water supply, the heater 1 is energized by the first temperature setting circuit 8, so that when the temperature rises to 85° C. or higher, the sales operation becomes possible. In addition, if the heater 1 is not energized due to a disconnection of the heater 1, etc., the temperature inside the tank will further decrease until the fourth temperature setting circuit 27 detects a temperature below 63°C. The power supply circuit is then cut off by a relay 34.

In this situation, timer 4 will cause 23
When the time comes, the switch 5' is switched by the relay 5 and switched to the second temperature setting circuit 9 side (Fig. 2.24).
(indicated by 23:00 on the timer). Since this second temperature setting circuit 9 is set at 68°C, the temperature that was previously maintained at 90°C in the first temperature setting circuit 8 is now 68°C.
℃, and the third temperature setting circuit 22 stops the vending operation of the vending machine.

Further, at 7:00 o'clock the next day, the timer 4 switches the switch 5' of the relay 5 to control the energization of the heater 1 by controlling the first temperature setting circuit 8 to 90°C. In addition, the vending operation of the vending machine will remain in a stopped state unless 85°C is detected by the third temperature setting circuit 22 (see Figure 2).
switching from off to on).

Note that when the sale is canceled by the fourth temperature setting circuit 27, the suspension of sale is maintained as long as the reset switch 30 is not operated.

As a result of the above, it is possible to save power by stopping the vending machine's vending operation and lowering the water temperature in the tank by the heater 1 by the second temperature setting circuit 9 during times when the number of sales is significantly low, such as at night. In addition, when the time for this power saving ends, the first temperature setting circuit 8 switches to a circuit that maintains the temperature of the hot water at 90°C, but since the temperature is initially low, the first Since the operation of the vending machine is stopped by the temperature setting circuit 22 of No. 3, the temperature of the hot water supplied from the vending machine can be reliably compensated.

Effects of the Invention As described above, the present invention energizes the heater that heats the hot water tank using either the first temperature setting circuit or the second temperature setting circuit, which have different temperatures, and
The first and second temperature setting circuits are switched by a timer to maintain a low temperature for a certain period of time to save power, and to maintain the temperature between the first and second temperature setting circuits. A third temperature setting circuit that temporarily stops the vending operation of the vending machine is provided, and when the temperature is maintained at a low temperature, the vending machine also temporarily stops the operation and prohibits the supply of low-temperature hot water. It is something. Further, if a fourth temperature setting circuit whose temperature is lower than the first, second, and third temperature setting circuits is provided, and the fourth temperature setting circuit detects that the temperature inside the tank is low, This solves the problem under the Food Sanitation Law by stopping the vending machine and preventing further sales.

[Brief explanation of drawings]

FIG. 1 is a temperature control circuit for a hot water tank used in a vending machine according to an embodiment of the present invention, and FIG. 2 is a timing chart of FIG. 1. 1... Heater, 2... Temperature detection circuit, 8... First temperature setting circuit, 9... Second temperature setting circuit,
5'...Switch, 22...Third temperature setting circuit,
27... Fourth temperature setting circuit, 35... Switch circuit, 36... Stop circuit, 37... Stop circuit.

Claims (1)

[Claims] 1 a temperature detection circuit that detects the temperature of the hot water tank; a heater that heats the hot water tank; a first temperature setting circuit that sets the maintenance temperature of the hot water tank that is maintained by heating the heater; a second temperature setting circuit for maintaining the hot water tank at a temperature lower than the set temperature of the temperature setting circuit and higher than the prescribed temperature under the Food Sanitation Act; and a temperature set by the first or second temperature setting circuit. a switch circuit for controlling energization of the heater to a temperature of 24;
a switch that switches from the setting by the first temperature setting circuit to the setting by the second temperature setting circuit at night based on the output from the timer; and between the first temperature setting circuit and the second temperature setting circuit. a third temperature setting circuit set to a temperature of the third temperature setting circuit; a stop circuit that stops the vending operation and stops hot water supply in the hot water tank when the temperature of the hot water tank becomes lower than the set temperature of the third temperature setting circuit; a fourth temperature setting circuit that is set to a temperature lower than the specified temperature under the Sanitation Act; a stop circuit that stops the vending operation when the temperature of the hot water tank falls below the set temperature of the fourth temperature setting circuit; A hot water tank temperature control circuit for a vending machine, comprising a reset switch for canceling a sales cancellation operation caused by a cancellation circuit.