JPH0539420Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Purpose of invention] (Industrial application field) The present invention relates to a thermoelectric refrigerator.

(Prior art) Conventionally, by a method called thermoelectric cooling or electronic cooling, using the so-called Peltier effect,
Refrigerators that cool the interior of the refrigerator, that is, thermoelectric refrigerators, have been put into practical use.

Refrigerators that use a compressor to circulate refrigerant have a problem with the noise generated by the compressor, but thermoelectric refrigerators do not require such moving parts, so their cooling principle makes them susceptible to noise and vibration. There is no risk of wear on moving parts. Furthermore, it is easy to downsize the refrigerator, and it is also easy to control the temperature inside the refrigerator. Therefore, it is generally installed and used as a small-capacity refrigerator in a bedroom or the like.

Now, in conventional thermoelectric refrigerators, it is necessary to efficiently release heat outside the refrigerator in order to increase the cooling efficiency inside the refrigerator, so a radiator is installed on the heat radiation side of the thermoelectric element that has the Peltier effect. A fan motor is installed to air-cool this radiator.
Moreover, the thermoelectric element and fan motor are turned on at the same time.
The control circuit was configured to turn it off.

(Problems to be solved by the invention) Conventional thermoelectric refrigerators as described above have the advantage of no noise or vibration in their cooling principle, but they also use a fan motor to increase heat dissipation efficiency. Coupled with the fact that these fan motors are generally installed in bedrooms and the like, the noise and vibration generated by these fan motors becomes a problem, especially when people turn off the lights and go to bed.

In view of the above points, an object of the present invention is to provide a thermoelectric cooling type refrigerator that automatically stops the operation of the fan motor when it becomes dark outside the refrigerator.

[Structure of the invention] (Means for solving the problem) In order to achieve the above-mentioned object, the present invention uses a series circuit consisting of a fan motor and a switching element that turns on and off in response to the brightness and darkness outside the refrigerator. is connected in parallel to the power supply and a DC current supply circuit to the thermoelectric element.

(Function) When it is bright outside the refrigerator, a switching element connected in series to the fan motor turns on. Therefore, at the same time that current is supplied from the power source to the thermoelectric element to cool the inside of the refrigerator, current is also supplied to the fan motor, and heat is efficiently released from the radiator.

On the other hand, when it becomes dark outside the refrigerator, the switching element is turned off. Therefore, although current can be supplied to the thermoelectric element in this case as well, operation of the fan motor is prohibited.

(Embodiment) FIGS. 1 and 2 are an electric circuit diagram of a thermoelectric cooling refrigerator and a side view of this refrigerator, respectively, according to an embodiment of the present invention.

The fan motor 2 is connected in series with the contacts of a photo switch 4, which is turned on and off in response to the brightness and darkness outside the refrigerator. Of the connection points 6 and 8 at both ends of this series circuit, the connection point 6 is connected to the thermostat 10.
The power plug 12 is connected to one terminal of the power plug 12 through a contact point, and the other connection point 8 is directly connected to the other terminal of the power plug 12. A primary winding of a transformer 14 is further connected between the connection points 6 and 8. The secondary output of this transformer is passed through a rectifier circuit consisting of a diode 16 and a capacitor 18 to a thermomodule 20 having a Peltier effect.
has been entered. The thermomodule 20 includes, for example, a bismuth-tellurium compound-based P-type semiconductor and an N
It is a thermoelectric element in which a combination of several pairs is arranged, with one pair being a type semiconductor.

When a voltage is applied to the primary winding of the transformer 14, this voltage is stepped down by this transformer,
After being half-wave rectified by the diode 16 and capacitor 18, it is applied to the thermoelectric element 20, so that
A direct current can be supplied to this thermoelectric element.

A door 26 is provided in front of the refrigerator compartment 22 with a packing 24 interposed therebetween. A wall 30 separates and insulates the refrigerator compartment 22 from the heat radiation chamber 28 located behind it. Above this wall 30, the thermomodule 20 is arranged, and its heat absorption side 20a and heat radiation side 20b are exposed to the refrigerator compartment 22 and the heat radiation chamber 28, respectively. Refrigerator room 22
Inside, a large surface area cooler 32 is thermally connected to the endothermic side 20a of the thermomodule 20, to which the thermostat 10 is also attached. Inside the heat dissipation chamber 28, a heat dissipator 34 made of fins is thermally connected to the heat dissipation side 20b of the thermomodule 20.
are arranged so that air can be blown toward the radiator 34. In addition, the lower surface 36 of the heat radiation chamber 28
An intake port and an exhaust port are formed on the upper surface 38 and the upper surface 38, respectively. The photo switch 4 is preferably attached to the top of the outer surface of the refrigerator, but it may be placed anywhere as long as it can detect the brightness and darkness outside the refrigerator.

Now, the power plug 12 is connected to an AC power source. At this time, when the temperature inside the refrigerator is higher than the set temperature, the contact of the thermostat 10 is closed. Therefore, direct current is supplied to the thermomodule 20, and due to the Peltier effect, heat is absorbed and heat is radiated on the heat absorption side 20a and the heat radiation side 20b, respectively. At this time, since the cooler 32 has a larger contact area with the air in the refrigerator compartment 22, it has the effect of increasing heat absorption efficiency.

In this way, when heat is absorbed from the heat absorption side 20 of the thermomodule 20 via the cooler 32, this heat is transferred to the heat radiator 34 on the heat radiation side 20b.
The heat is released into the air inside the heat radiation chamber 28 through the heat radiation chamber 28. At this time, if it is bright outside the refrigerator, turn the photo switch 4.
Since the contacts are closed, current is also supplied to the fan motor 36. At this time, the air outside the refrigerator is sucked in from the intake port formed on the lower surface 36 of the heat radiating chamber 28, and after cooling the radiator 34, the air outside the heat radiating chamber 28 is
It is discharged from an exhaust port formed on the top surface of 8. Therefore, heat is efficiently radiated from the heat radiator 34, and therefore heat is efficiently absorbed by the cooler 32.

When the inside of the refrigerator compartment 22 is cooled in this way and its temperature becomes lower than the set temperature, the contacts of the thermostat 10 open. At this time, since no current is supplied to either the thermo module 20 or the fan motor 36, the inside of the refrigerator compartment 22 is not cooled.

As described above, the temperature inside the refrigerator compartment 22 is maintained at a constant temperature.

Now, when the outside of the refrigerator becomes dark due to lights being turned off, for example,
Since the contact of the photo switch 4 is opened, the supply of current to the fan motor 2 is prohibited. Therefore, at this time, the fan motor 2 does not rotate, and no noise or vibration will be generated. However, even if the rotation of the fan motor 2 is stopped, if the temperature inside the refrigerator compartment 22 becomes higher than the set temperature, the contacts of the thermostat 10 close, current is supplied to the thermo module 20, and the temperature inside the refrigerator compartment 22 is increased. is cooled. However, even when the thermomodule 20 is driven, no noise or vibration is generated from the thermomodule. At this time, since the fan motor 2 does not blow air, the heat radiation efficiency of the radiator 34 decreases, but when the lights are off, the number of times the door 26 is opened and closed is small, and the outside temperature is often relatively low. , this decrease in heat dissipation efficiency usually does not pose a problem.

FIG. 3 is an electrical circuit diagram of a thermoelectric refrigerator according to another embodiment of the present invention.

The only difference from the previous one is that a second thermostat 40 is further provided in parallel with the photo switch 4, so a description of the other points will be omitted.

This thermostat 40 is attached to the cooler 32 in the same way as the thermostat 10, but
Its opening/closing set temperature is set higher than that of the thermostat 10. Therefore, although the inside of the refrigerator compartment 22 is cooled by supplying direct current to the thermo module 20, the temperature inside the refrigerator compartment 22 may rise abnormally due to frequent opening and closing of the door 26, for example. In this case, even when it is dark outside the refrigerator and the contacts of the photo switch 4 are open, the contacts of the thermostat 40 are closed and the fan motor 2 is closed.
Current is supplied to At this time, the heat radiator 34
Since the refrigerator compartment 22 is air-cooled and its heat dissipation efficiency is improved, the inside of the refrigerator compartment 22 is rapidly cooled. Therefore, since the rotation of the fan motor 2 is limited to a short period of time, noise and vibration generated from the fan motor do not pose a problem.

Although the photo switch 4 has been used in the above description, it may be any switching element that turns on and off in response to the brightness and darkness outside the refrigerator, such as a photo transistor. Further, the DC current supply circuit to the thermomodule 20 is not limited to the circuit consisting of the transformer and the half-wave current circuit, but may be a circuit including a full-wave rectifier circuit or the like.

[Effects of the invention] In this invention, a series circuit consisting of a fan motor that air-cools a radiator attached to a thermoelectric element and a switching element that turns on and off according to the brightness and darkness outside the refrigerator is connected to a power supply. , is connected in parallel with the DC current supply circuit to the thermoelectric element, so when it gets dark outside the refrigerator, current can be supplied to the thermoelectric element to cool the interior of the refrigerator, but the fan motor cannot be operated. automatically banned. Therefore,
At this time, it is possible to provide a refrigerator that does not generate noise or vibration during cooling and takes full advantage of the thermoelectric cooling type.

[Brief explanation of the drawing]

FIG. 1 is an electric circuit diagram of a thermoelectrically cooled refrigerator according to an embodiment of the present invention, FIG. 2 is a side view of the refrigerator, and FIG. 3 is a thermoelectrically cooled refrigerator according to another embodiment of the present invention. FIG. Explanation of symbols, 2... Fan motor, 4... Photo switch, 10... Thermostat, 14...
Transformer, 16... Diode, 18... Capacitor, 20... Thermo module, 22... Refrigerator room, 28... Heat radiation chamber, 32... Cooler, 34...
radiator.

Claims (1)

[Scope of utility model registration request] A thermoelectric cooling type refrigerator including a thermoelectric element having a Peltier effect, in which a radiator attached to the thermoelectric element is air-cooled by a fan motor, and a switching element that turns on and off in response to the fan motor and the brightness outside the refrigerator. A thermoelectric cooling type refrigerator characterized in that a series circuit consisting of the above is connected to a power source in parallel with a DC current supply circuit to the thermoelectric element.