Thermostat for do-it-yourself heating

I present an electronic development - a homemade thermostat for electric heating. The temperature for the heating system is set automatically based on changes in outdoor temperature. The thermostat does not need to manually, make and change the readings to maintain the temperature in the heating system.

In the heating system, there are similar devices. For them, the ratio of the average daily temperature and the diameter of the heating pipe is clearly spelled out. Based on these data, the temperature is set for the heating system. Based on this table, the heating system. Of course, some factors are unknown to me, the building may be for example, not insulated. The heat loss of such a building will be large, heating may be insufficient for normal space heating. The thermostat has the ability to make adjustments for tabular data. (You can also read the material on this link ).

I planned to show a video in the operation of the thermostat, with an eclectic boiler (25Kv) connected to the heating system. But as it turned out, the building for which all this was done was not residential for a long time, when checked, the heating system was almost completely unusable. When everything is restored, it is not known, perhaps it will not be this year. Since in real conditions I cannot adjust the thermostat and observe the dynamics of changing temperature processes, both in heating and on the street, I went the other way. For these purposes, built a layout of the heating system.
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The role of electric boiler, performs a glass floor liter jar, the role of the heating element for water - five hundred wadded boiler. But with such a volume of water, this power was in excess. Therefore, the boiler connected through a diode, lowering the power of the heater.

Connected in series, two aluminum flow radiators, perform heat extraction from the heating system, forming a semblance of a battery. With the help of the cooler, I create the cooling dynamics of the heating system, since the program in the thermostat monitors the rate of rise and fall of the temperature in the heating system. On the return pipe, there is a digital temperature sensor T1, on the basis of the readings of which the set temperature in the heating system is maintained.

In order for the heating system to start working, it is necessary that the T2 (street) sensor records a drop in temperature, below + 10 ° C. To simulate changes in outdoor temperature, designed a mini fridge on the Peltier element.

It makes no sense to describe the work of the entire self-made installation, I filmed everything on video.





Some points about the assembly of electronic devices:

The thermostat electronics is placed on two printed circuit boards, you will need the SprintLaut program, not lower than version 6.0, for viewing and printing. The thermostat for heating is mounted on a din rail, thanks to the Z101 series case, but something does not interfere with placing all the electronics in another case of a suitable size, the main thing is to suit you. In the case of the Z101 window is not provided for the indicator, so you have to independently mark and cut. The ratings of the radio components are shown in the diagram, except for the terminal blocks. I used terminal blocks of the WJ950-9.5-02P series (9 pcs.) To connect the wires, but they can be replaced by others. When choosing, take into account that the step between the legs is the same, and the height of the terminal block does not prevent the housing from closing. In the thermostat, a microcontroller is used, which needs to be programmed, of course, I also provide the firmware for free access (it may be necessary to modify the process). Flashing the microcontroller, set the operation of the internal clock generator of the microcontroller to 8 MHz.

PS Of course, heating is a serious matter and most likely you will have to modify the device, so the final device cannot be called yet. All changes that the thermostat will undergo in the future I will make.

Download: Firmware, printed circuit boards