A great craft for the summer is to make a miniature refrigerator with low-voltage power. A variety of supply voltages (220 V, 12 V, 5 V) makes it possible to use such a refrigerator almost anywhere: in the car, office, home, etc. This is a great thing to cool drinks on a hot summer day.
Will need
- The cooling unit, which consists of a Peltier element, three fans and a radiator - You can buy it HERE on Ali Express.
- Switching power supply 12 V 10 A - You can buy it HERE on Ali Express. This unit is needed if you want to power the refrigerator from a 220 V AC network.
Manufacturing a miniature refrigerator using a Peltier element
The case was made of arbitrary dimensions, taking into account the placement of the cooling unit, power supply and beverage chamber. It will consist of two sections: one for the technical part, the other for cooling products.
We make the body. We mark a piece of hardboard using a pencil and ruler.
We cut out all the elements with a hacksaw.
All body parts are ready.
From the middle part dividing the refrigerator into two parts, we cut out a window for a radiator with a Peltier module.
We apply the cooling unit to the side of the case.
And we drill a lot of holes on both sides. That is, the air flow will enter from one side through the holes in the side. Pass through the radiator, picking up heat and exiting through the holes on the other side.
We paint all parts of the refrigerator body with aerosol paint from a can.
Let's start assembling.
Glue the separating part of the cooling block with hot glue.
We glue all parts of the body on both sides.
The cooling unit rests on a piece of wood that is glued to the base.
For illumination, you will need two sections of 12 V LED strip. One color is white, the other color.
Screw on the small fan.
We divide the technical part of the refrigerator into two parts. The power source will be located at the top. The dividing wall is placed on square pieces of wooden slats glued to the sides.
Installing the back wall.
We will make the door from a piece of acrylic glass. Mark with a ruler and pencil.
You can buy miniature loops or make your own. Glue them on with instant glue.
We cover the sides of the acrylic glass with black self-adhesive tape.
Glue the handle to the door.
We will organize lighting. Solder the contacts to the mini limit switch.
Solder the wires to the pieces of LED strip. We glue the pieces themselves onto a mini shelf made from the same acrylic.
We connect the backlight, fans, Peltier element.
Install the switch on the side.
We isolate all open twists.
Close the compartment with the cooling unit. This must be done to prevent hot air from rising up and heating the power source.
Drill a hole for the 220 V power cable.
To prevent the refrigerator door from opening, we will install small neodymium magnets from a broken sidir on the side.
We close the top cover, but before that we cut in the power switch and solder the wires. Now the refrigerator can be turned off with the button on top.
Close the lid and secure with glue.
For proper thermal insulation, we cover the inside of the refrigerator with thin foam plastic. We place the cut out foam panels on hot glue.
We make cutouts in the plates for all the protrusions and parts.
Now the useful cold will not be wasted and the efficiency of the refrigerator will increase.
At the very end, we add an electronic thermometer on the inside, and place its sensor closer to the small fan that is located inside the chamber.
Mini refrigerator operation
This is what a refrigerator looks like in the dark with the door closed.
When opened, the white light comes on and the color light turns off.
And finally, the result of the work is such that in thirty minutes the temperature inside the chamber dropped from 42 to 16 degrees Celsius. The drinks were cooled to a temperature of 20 degrees Celsius. And all this in 30 minutes!
Of course, the efficiency of such a refrigerator is much lower than that of a compressor, but it also has its advantages, one of which is low-voltage power supply, which can be not only 12 V but also 5 V! Naturally, it is quite possible to power it from a computer’s USB port, although the output will be lower than when powered by a voltage of 12 V.
The total power consumption when powered from a 220 V network is about 100 W.
Watch the video
More detailed assembly instructions in the video below.
