JP2000249453A - Low temperature show case - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low temperature show case including a decision circuit for on/off of a fluorescent lamp of the low cost without additionally providing excessive parts. SOLUTION: In a low temperature show case including a judgement circuit 31 for judging on and off of a fluorescent lamp 10 for illumination in a chamber, and alteration means for altering temperature adjusting set temperature based upon a judgement of the judgement circuit 31, an electronic stabilizer 25 is provided on an ignition circuit 23 of the fluorescent lamp 10, and the judgement circuit 31 is connected with a DC smoothing circuit 27 of the electronic stabilizer 25, which judgement circuit 31 judges on and off of the fluorescent lamp 10 with a DC signal from the DC smoothing circuit 27.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-temperature showcase provided with a fluorescent lamp for interior lighting.

[0002]

2. Description of the Related Art Generally, a low-temperature showcase comprising a judgment circuit for judging whether a fluorescent lamp for interior lighting is turned on or off, and changing means for changing a set temperature for temperature control based on the judgment of the judgment circuit. It has been known. In this type, for example, when a fluorescent lamp is lit during opening of a store, the set temperature for temperature control is set to be low, and temperature control is performed to compensate for the heat radiation of the fluorescent lamp. When the fluorescent lamp is off, the set temperature for temperature control is set high, the cooling capacity is suppressed, and energy saving is achieved (this function is called a night set back function). Conventionally, an AC voltage sensor is connected to a power supply line of AC 100 V / 200 V in a lighting circuit of a fluorescent lamp, converts the AC voltage sensor into a DC voltage, and determines whether to turn on / off the fluorescent lamp based on a DC signal from the sensor. In this manner, the night set back function is operated.

[0003]

However, in the conventional configuration, there is a problem in that the component voltage increases because the AC voltage sensor includes expensive high-voltage components.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a low-temperature display having a circuit for judging whether to turn on / off a fluorescent lamp without adding extra parts and keeping the cost low. Is to provide a case.

[0005]

According to a first aspect of the present invention, there is provided a determination circuit for determining whether to turn on / off a fluorescent lamp for interior lighting, and a setting temperature for temperature control based on the determination by the determination circuit. A low temperature showcase comprising a changing means for changing the fluorescent lamp, an electronic ballast is provided in a lighting circuit of the fluorescent lamp, and the determination circuit is connected to a DC smoothing circuit of the electronic ballast, and the determination circuit is a DC smoothing circuit. The lighting / extinguishing of the fluorescent lamp is determined on the basis of a DC signal from the controller.

According to the present invention, the determination circuit determines whether to turn on or off the fluorescent lamp based on the DC signal output from the DC smoothing circuit of the electronic ballast. , The configuration for detecting the output voltage of the lighting circuit is simplified, and the cost of parts can be reduced.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 20 denotes a low-temperature showcase installed in a supermarket or the like. The low-temperature showcase 20 includes a heat-insulating box 1 having an opening on one side, and a cooler 2 including an evaporator constituting a refrigeration cycle is provided below the heat-insulating box 1. Then, a cool air passage 5 is formed from a suction port 3 provided at a lower portion of the heat insulating box 1 to a cooler 2, an inner back surface of the heat insulating box 1, and an outlet 4 provided at an upper portion of the heat insulating box 1. The cool air cooled in the cooler 2 by the fan 6 is circulated as indicated by an arrow to supply cool air to the inside 7 of the refrigerator.
Air is blown into the opening of the heat insulating box 1 from the outlet 4 to the inlet 3.
Curtains are formed to cool the goods displayed on the shelf 8 for goods display in the refrigerator 7 and on the deck pan 9 on the wire rack to keep the goods at a low temperature. A fluorescent lamp 10 for interior lighting is provided on the back surface of the shelf 8 and in the vicinity of the outlet 4.

A temperature sensing tube 1 is provided in a cool air passage 5 inside the air outlet 4.
4 is provided, and the thermostat main body 11 is
The temperature setting knob 12 is exposed to the outside at the upper portion of the reflector 16 at the front of the device, and the setting temperature Ts can be set to an arbitrary value by adjusting the temperature setting knob 12.

Next, a description will be given of a temperature control device in the refrigerator 7.

In this embodiment, as shown in FIG.
An electronic ballast 25 is provided in the lighting circuit 23 of the fluorescent lamp 10 connected to the 00 V / 200 V AC power supply 21. The electronic ballast 25 includes a DC smoothing circuit 27 for generating a DC voltage inside, and the DC smoothing circuit 27 is connected to a controller 31 via a signal line 29. This DC smoothing circuit 27 constitutes an output means for outputting a DC signal.

When a store such as a supermarket is opened, the fluorescent lamp 10 is turned on, and a DC signal indicating that the fluorescent lamp is turned on is output from the DC smoothing circuit 27 of the electronic ballast 25 to the controller 31. The controller 31 determines the lighting of the fluorescent lamp 10 and sets a preset temperature Tl (= Ts−ΔT1 ° C.) obtained by previously subtracting an apparent measured temperature ΔT1 ° C. from the set temperature Ts set by adjusting the temperature setting knob 12. The drive of the refrigeration cycle is controlled on the basis of, and the temperature of the inside of the refrigerator 7 is maintained in a predetermined temperature zone around the set temperature Tl. The controller 31 includes a determination circuit that determines whether the fluorescent lamp 10 is turned on or off based on a DC signal output from the DC smoothing circuit 27.

On the other hand, when the store is closed, a night cover (not shown) is hung over the opening of the heat insulating box 1 and the fluorescent lamp 1 is closed.
0 is turned off, and a DC signal indicating that the fluorescent lamp is turned off is output from the DC smoothing circuit 27 of the electronic ballast 25 to the controller 31. When a night cover (not shown) is hung over the opening of the heat-insulating box 1 to prevent outside air from entering, and when a DC signal indicating that the fluorescent lamp is turned off is output, the controller 31 sets the set temperature Ts to As a reference, the refrigeration cycle is drive-controlled to maintain the seven internal temperatures in a predetermined temperature zone centered on the set temperature Ts. Note that the above control is merely an example, and it is obvious that the present invention is not limited to this.

In this embodiment, for example, the fluorescent lamp 1
When 0 is lit, the set temperature Tl for temperature control is set low, and temperature control is performed to compensate for the heat radiation of the fluorescent lamp 10, while, for example, when the fluorescent lamp 10 is turned off when the store is closed,
The set temperature Ts for temperature control is set high, the cooling capacity is suppressed, and energy saving is achieved (this function is called a night set back function). In this embodiment, a direct current signal is output to the controller 31 by using the direct current smoothing circuit 27 of the electronic ballast 25, and the turning on / off of the fluorescent lamp 10 is determined based on the direct current signal. As compared with the one of the above, the configuration for detecting the output voltage of the lighting circuit 23 including the electronic ballast 25 is simplified, and the cost of parts can be reduced.

Although the present invention has been described based on one embodiment, it is clear that the present invention is not limited to this. For example, in the above embodiment, an example in which the DC smoothing circuit 27 of the electronic ballast 25 is used has been described. However, the present invention is not limited to this, and another DC voltage output unit may be used.

[0016]

According to the present invention, the determination circuit determines whether to turn on / off the fluorescent lamp based on the DC signal output from the DC smoothing circuit of the electronic ballast. The configuration for detecting the output voltage of the lighting circuit including the ballast is simplified, and the cost of parts can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a low-temperature showcase.

FIG. 2 is a configuration diagram in which a determination circuit is connected to a lighting circuit of a fluorescent lamp.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulated box 2 Cooler 3 Inlet 4 Outlet 5 Cold air passage 6 Fan 7 Inside 8 Shelf 10 Fluorescent lamp 21 AC power supply 23 Lighting circuit 25 Electronic ballast 27 DC smoothing circuit 31 Controller (judgment circuit)

Continued on the front page (72) Inventor Masato Fukumoto 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Takeshi Aoki 2-5-2-5 Keihanhondori, Moriguchi-shi, Osaka F term in Sanyo Electric Co., Ltd. (reference) 3B110 AA03 BA06 CA00 3L045 AA02 BA01 CA02 DA01 EA01 HA01 KA01 LA01 LA11 MA20 PA02 PA04

Claims (1)

[Claims] 1. A low-temperature showcase comprising: a judgment circuit for judging on / off of a fluorescent lamp for interior lighting; and changing means for changing a set temperature for temperature control based on the judgment of the judgment circuit. An electronic ballast is provided in a lighting circuit of the fluorescent lamp, and the determination circuit is connected to a DC smoothing circuit of the electronic ballast. The determination circuit turns on / off the fluorescent lamp by a DC signal from the DC smoothing circuit. A low-temperature showcase characterized by a configuration for determining.