JPH0589336A - Automatic vending machine - Google Patents

Abstract

PURPOSE:To easily and highly reliably suppress the overall used current of an automatic vending machine. CONSTITUTION:A lighting circuit 1, a cooling circuit 2, plural heater circuits 4,5, a current detection circuit 11 to detect the overall used current of all these load circuits, and a current control circuit 12 to output a control signal to the heater circuits, 4,5 are provided. The heater circuits 4,5 are constituted so that switching circuits in which thyristors are anti-parallel-connected are serial-connected to each heater, and a heater current I is adjusted by turning ON/OFF this thyristor, and the detected overall current at the current detection circuit 11 is suppressed so as to be below a prescribed current value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot and cold type vending machine having a cooling device and a plurality of heating heaters.

[0002]

2. Description of the Related Art In recent years, a cooling device and a heating device having a heater and the like have been incorporated, and a plurality of storage chambers are divided into cooling and heating chambers to store hot products such as canned coffee and cold products. Vending machines that sell products together have become widespread.

In this case, there is a control circuit as shown in Japanese Utility Model Laid-Open No. 3-6777 for switching between heating and cooling and its control.

[0004] And, these hot and cold type vending machines are becoming larger and more deluxe year by year,
Along with this, the number of lighting devices that illuminate the signboards increases, and the number of storages increases, so the number of heating devices also increases accordingly.

As a result, the total amount of current used by the vending machine exceeds the specified safe current, which is a problem from the viewpoint of energy saving and environmental problems. ..

[0006]

Conventionally, as shown in FIG. 4, for controlling the energization of the heater, a circuit in which only the thermo-contact 25 is connected in series to the heater (H) 26 is used to reduce the current.
% Or 100% energization, or a circuit using a thermo contact 27 and a diode 29 assembled in parallel with a relay contact 28 as shown in FIG.
A method of energizing 50% or 100% was adopted.

However, the above-mentioned current control by the conventional energization method uses the contact, so that the phenomenon of defective contact operation may occur, and there is a drawback of lacking reliability.

Further, if the number of heater circuits is increased, the wiring circuit becomes complicated, which makes it difficult to assemble and increases the cost.

The present invention has been made in view of the above points,
The non-contact circuit makes it possible to easily control the heater energizing current, and to perform effective current control for suppressing the total current used.

[0010]

According to the present invention, there is provided a cooling circuit for driving a compressor for cooling a plurality of storage chambers arranged in a refrigerator and a fan for circulating cold air, and an illumination circuit for illuminating a product display section. For the heaters arranged in each storage room, the total current value used in the multiple heating circuits with the circuit configuration in which the switching circuits of anti-parallel connection of thyristors are connected in series and the cooling circuit, lighting circuit and heating circuit are shown. A current control circuit that compares the current detection circuit to detect and the current value detected by this current detection circuit with the specified current value and outputs the conduction control signal to each thyristor to control the heater energization current to each heater circuit. It is equipped with and.

[0011]

The operation current of the heater provided for each storage chamber is turned on and off by the control signal output from the current control circuit of each thyristor connected in series and antiparallel to the heater.
By controlling, it can be controlled in a wide range.

The total current including the plurality of heater circuits and other lighting circuits, cooling circuits, etc. is detected by the current detection circuit and is suppressed to a specified current value or less to prevent wasteful power consumption.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of an electric circuit of the present invention for controlling a current supplied to a heater. In FIG. 1, reference numeral 1 denotes a lighting circuit, which includes a plurality of fluorescent lamps and a lighting device.
Reference numeral 2 denotes a cooling circuit, which is configured to include devices such as a compressor, a cold air circulation fan motor, and a refrigerant flow control valve.

The heater circuit 4 and the heater circuit 5 relate to a heating device respectively arranged in separate storage chambers A and B, and as will be described in detail later, a heater and a non-contact semiconductor switching device such as a thyristor. It has a circuit configuration including a circuit section including elements. Reference numeral 6 designates a temperature detection section composed of a temperature detection sensor arranged in the storage room A and a conversion circuit for the sensor output thereof, for detecting the heating temperature in the storage room A (for detecting the cooling temperature). Is also applied). Similarly, for the storage room B, the temperature detecting section 7 having the same configuration is provided. Reference numeral 8 is a control circuit for controlling the entire vending machine. In addition to the load circuits such as the lighting circuit 1, the cooling circuit 2 and the heater circuits 4 and 5 described above, other devices such as a product carry-out device, a coin counting device and a change dispensing device are also provided. It controls the entire sales operation including the load circuit of. Each of these load circuits is supplied with power from the commercial power supply 10.

Therefore, a current detection circuit 11 for detecting the total current value used in these load circuits as a whole is provided at the power supply input terminal. The current value f detected by the current detection circuit 11 is input to the current control circuit 12. This current control circuit 12 is for controlling the current flowing to the heater,
It is an electronic circuit of a microcomputer configuration, and control signals S1 and S2 are supplied to the heater circuits 4 and 5, respectively.
Is output to suppress the total current value. On the other hand, the temperature detection signals a and b from the temperature detection units 6 and 7 are input to the current control circuit 12, the ON / OFF signal c of the lighting device is supplied from the lighting circuit 1, and the cooling operation ON / is supplied from the cooling circuit 2. OFF signal d is input,
The operating state of each circuit can be grasped. If the temperature detection signals a and b have detection output values equal to or higher than a predetermined set temperature value, the heater circuits 4 and 5 are off,
If the detected output value is equal to or lower than the predetermined set temperature value, the current control circuit 12 can determine whether the heater circuit is ON.

The current control circuit 12 turns on the heater circuits 4 and 5 depending on the presence / absence of the detection signals a, b, c and d described above.
The current detection circuit 11 includes a memory unit for storing the ON / OFF state and the total current value I detected by the current detection circuit 11, and also for storing a preset current value (safe current value). It also includes a judgment circuit for comparing and judging the detected total current value with the specified current value. Therefore, when the judgment circuit judges that the total current exceeds the specified current value, the control signal is sent from the current control circuit 12 to either the heater circuit 4 or the heater circuit 5 or to both the heater circuit 4 and the heater circuit 5. Send S1 and S2,
Reduce the total current value by lowering the energizing current of the heater.

FIG. 2 shows a specific circuit of the heater circuits 4 and 5. The heater circuit 4 includes a heater (H ₁ ) 15, a thyristor (Th ₁ ) 16, and a thyristor (Th ₂ ).
Reference numeral 17 is a circuit configuration in which non-contact type switching circuits connected in antiparallel are connected in series. The control signal S1 from the current control circuit 12 is input to the gate Th ₁ G of the thyristor 16 and the gate Th ₂ G of the thyristor 17 to control ON / OFF of the thyristors 16 and 17.

Similarly, in the heater circuit 5, a non-contact type switching circuit formed by the antiparallel connection of the thyristor (Th ₃ ) 19 and the thyristor (Th ₄ ) 20 is connected in series to the heater (H ₂ ) 18, and the thyristor 19 is connected. The control signal S2 from the current control circuit 12 is input to the gate Th ₃ G of the thyristor 20 and the gate Th ₄ G of the thyristor 20.
ON / OFF control of 9 and 20 is performed.

The specific control of the energizing current to the heater (H ₁ ) 15 will now be described with reference to the timing chart of FIG. 3. For example, when it is desired to energize the heater (H ₁ ) to 50%, The control signal S1 is sent to either the thyristor Th ₁ or the thyristor Th ₂ to turn it on. That is, as shown in the timing chart, in the zones (a) and (c) where only the thyristor Th ₁ or the thyristor Th ₂ is in the ON state, the half-wave rectified current flows to the heater H ₁ and the conduction current is controlled to 50%. And when it is desired to make the heater H ₁ energized 100%, the thyristor T
Control signal S1 is sent to both h ₁ and Th ₂ and both thyristors T
Turn on h ₁ and Th ₂ . In the zone (b) where both thyristor Th ₁ and thyristor Th ₂ are in the ON state,
A full-wave rectified current flows to the heater H ₁ and the energizing current is 10
It is controlled to 0%.

A control signal S is applied to both the gates Th ₁ G and Th ₂ G.
If 1 is not entered, no current flows through the heater H ₁ . This 0% energization is in zone (d) (d).

Heater (H ₂ ) in the heater circuit 5
Similarly, in the case of 18, the heater (H ₂ ) 18 can be energized at 0% (OFF) 50% and 100% easily without contact.

Table 1 below shows the relationship between the ON / OFF control of the thyristors Th ₁ , Th ₂ and Th ₃ , Th ₄ and the energizing current value I resulting therefrom.

In Table 1 above, I ₁ > I ₂ > I ₃ = I ₄ = I ₅ > I ₆
> And has a relationship of I _7. Therefore, the heater circuits 4, 5
It is possible to control the total current value of the heater current flowing in 5 steps in 5 steps.

[0024]

As described above, according to the present invention, a heater circuit configuration in which a non-contact type switching circuit of a thyristor connected in antiparallel is connected in series to a heater arranged in each storage chamber, and a full load current is obtained. Depending on the detected current value from the current detection circuit that detects the current, a signal is selectively sent to the thyristor, and a current control circuit that controls the heater energizing current in multiple stages is provided to keep the working current below the specified safe current value. Since it is easy to hold down and it is a non-contact type, it can be performed with high reliability and excellent responsiveness. This saves energy and is useful as a heater energization control circuit for vending machines.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram of the present invention for controlling the total current of a vending machine having various load circuits.

FIG. 2 is a specific internal circuit diagram of a heater circuit.

FIG. 3 is a timing chart illustrating the controllability of the heater energization current.

[Figure 4] Conventional heater circuit diagram

FIG. 5: Another conventional heater circuit diagram

[Explanation of symbols]

 1 Lighting circuit 2 Cooling circuit 4.5 Heater circuit 10 Commercial power supply 11 Current detection circuit 12 Current control circuit 15.18 Heater 16.17.19.20 Thyristor

Claims (1)

[Claims] 1. A cooling circuit for driving a compressor, a cool air circulation fan, etc. for cooling a plurality of storage chambers arranged in a refrigerator, an illumination circuit for illuminating a product display section, etc., and a cooling circuit for each storage chamber. A plurality of heater circuits having a circuit configuration in which a switching circuit of a thyristor connected in anti-parallel is connected in series to the heater, and a current detection circuit for detecting all current values used in the cooling circuit, lighting circuit, heater circuit, etc. , A current control circuit that compares the detected current value from this current detection circuit with a specified current value, outputs a conduction control signal to each thyristor, and controls the heater energization current to each heater circuit. Characteristic vending machine.