Hello, dear readers and DIY!
It’s the season of hot weather, and when camping always want cool drinks. This helps a little thermo baghelps to preserve the temperature of products taken from the home refrigerator.
However, most of You are going to nature on a personal car, and often purchases products on the way.
In this article, the author’s YouTube channel, “GEEK” will tell You how he made a small portable fridge powered by 12V that can be connected to the cigarette lighter in the car.
This project is relatively simple to manufacture, and requires no welding.
— Peltier thermoelectric modules TEC1-12706
— Digital thermostat 12 In W1209
— Digital thermostat 12 IN W1209WK
— A thermally conductive adhesive
— Thermal grease
— Plug (with fuse) for the cigarette lighter
— Heat sinks for computer processors, fans
— Neodymium magnets
White led light strip
— Self-adhesive film Oracal
— Polystyrene sheet with a thickness of 20 mm
— Aluminum sheet, plate
— Laminate, QSB plate, fiberboard, colored plexiglass,
Glue “liquid nails”, silicone sealant, spray paint
— Wire, solder, shrink tube, terminal blocks, power connector, switch, grommet
— Sandpaper, screws for wood, bolts M10.
The tools used by the author.
— Digital infrared non-contact thermometer
— Electric jigsaw
— An angle grinder, cutting disc
— Disc sander attachment
— Electric soldering iron with adjustable temperature
— Knife for deburring
— Drill, metal drills, taps
— Clamp, combination angle ruler, marker, screwdriver, knife, pencil.
The process of making.
After all, the heart of this device will serve two 12V thermoelectric Peltier module TEC1-12706, with the stated cooling capacity of 50 W and current consumption of 4 to 6 A.
The size of these modules 40X40X3,75 mm.
For efficient and durable modules, they need a good cooling of the “hot” side. For this purpose the author will use the old radiators with fans for computer processors.
The material for the outer part of the body should be selected so that it is not afraid of moisture (condensation can occur). The author decided to make it from scraps of laminate, glue together three strips.
From this sheet using an electric jig saw, cut the panels for the side walls, cover, bottom, and facade doors.
Bulkhead to the rear of the case is cut from a plate QSP (it is made smaller than OSB).
To connect the parts of the design, the author additionally glued and screwed short screws small strips of laminate to the inner sides thereof.
The result is that such housing walls.
All these elements come together, the seams sealed with silicone.
Note that the upper and lower part of the body slightly bent forward, it is necessary to install the doors.
As a cooling radiator, which is located on the inner rear wall of the refrigerator, will serve as sheet aluminium 5 mm thick.
This material is cut such corners and strips. After cutting their edges chamfered with a special knife, and the surface is processed by the grinder with a disc sander attachment.
Now the corners are drilled and sensource holes for screws with countersunk heads. The corners sit on the silicone, and bolted to the hull.
In a similar way close the open ends of the laminate.
In the door panel, the author cut a window for the controller, and produced a box of blue plexiglass.
To maintain the desired temperature will be 12 In W1209 digital thermostat.
Its buttons are too short and click them without making extensions, or transfer on the front panel will not work. Therefore, the author removed the relay and two terminal blocks. The wires from the temperature sensor it is soldered to the Board directly.
In addition, the relay was moved closer to the thermocouples, because consumption of current is quite large, and the shorter and thicker will be the wire, the better. Was also soldered the power wires to the Board.
In the glass master drilled the holes for the buttons, the controller is secured with a plastic jumper wire and hot glue.
The perimeter of the window and door frames sealed with silicone.
By the way, not to bother with cutting the box and resoldering the card, you can use a mortise version of a thermostat W1209WK. On one dial displays the current temperature, and the second — set.
Now we need to arrange the hanger doors.
In the bottom corner of the door is glued a pin in the bottom is the return hole for him. And on the top corner of the door is drilled a hole, in which is embedded the spring from a lighter, and inserted a cylindrical rod.
With this door latch will snap into place.
Insulating material will be expanded polystyrene with a thickness of 20 mm., the Author cuts from it six rectangular parts.
From inside of the heater door he cut out the recess under a temperature sensor.
To level a surface, the sensor is glued to the aluminium plate of special heat-conductive glue.
All internal surfaces are pasted over with a white film Oracal (cutting it you can get any advertising Agency).
If you wish you can use adhesive tape made of aluminum foil, it improves the insulation.
Then installed the linings of aluminum corners, and the excess film is cut.
The heatsink will serve as a rectangular aluminum plate, to which the author attaches two parallelepiped made of aluminum plate with a thickness of 16 mm. These coasters are needed for the Peltier elements were beyond the insulating layer of Styrofoam.
The stands are drilled for mounting to the radiator, and tapped M3.
Before installation, at the junction of the supports and heatsink pre-applied thermal paste.
The result is that this design. Radiators clamped between the Peltier elements, given the location of the “hot” and “cold” sides, connections to apply thermal grease.
Insulation boards are fixed inside the body of the silicone, the seams are sealed.
The author has included a small lamp at the top of the refrigerator. This is one section on the three LEDs of led strip, encased in a box of blades for a knife.
Around the perimeter of the hull is glued to the usual sealing gum for Windows.
The Peltier elements and fans are connected in parallel, and will be included at the command of the thermostat by means of a relay.
The lamp and the payment of the thermostat are connected directly to the power connector.
The back wall is made from MDF and painted with spray paint. It fixed the fans so that they were in front of the radiators.
At the top of the wall made the hole for hot air outlet, and secure with a piece of mosquito net.
Also in the door, the author established a couple of neodymium magnets and made from bolts adjustable platform. This design will allow you to adjust the contact force of the door.
When you switch the refrigerator from 12 V power supply, the current is about 7.5 A. after some time it decreases to 6.35 A.
The initial temperature of the drinks was 26 degrees.
The author carried the fridge outside, where the temperature is over 27°C, and connected it to the car battery.
For measurement, the author uses a non-contact thermometer.
After an hour the temperature on the controller was + 15.7°C (despite the fact that the sensor is located far from the heater and the insulation in this place is not very thick).
The radiator is cooled down to 6.7°C, and drinks cooled to 10.5.
Here’s a fridge for car, garage, or workshop happened.
Of course, like the portable car refrigerator can be bought on Aliexpress, is one of the cheapest models cost about 2600 rubles. This device comes also with a heating function, so it can be used in the cold season to warm food or drinks.
The author’s version has almost twice the internal volume, and holds four 2L bottles of drink.
I thank the author for advice on making a portable refrigerator based on Peltier elements!
Of course, the size of the refrigerator you can make more or less. You can also increase the capacity by installing additional Peltier elements or using elements of more power.
All good mood, sound health, and interesting ideas!
The author’s video can be found here.
Hello, dear readers and DIY!