The mechanical thermostat K-50-l (to the fridge)
Offer type: salePublished: 17.03.2016
| Price: | 135 UAH |
| Company: | Timbereks-YuA |
| Seller: |  Salaev Vasilij Nikolaevich |
| Phones: |  +380688610676 Show phone |
| Address: | Ukraine, Kyiv |
Device thermostat
The thermoregulator is designed for maintaining in the fridge the set temperature by automatically switching off and on the compressor motor (compression refrigeration) or heater (in absorption refrigerators).
When adjusting the cooling capacity by periodic stops and starts of the unit, the temperature in the fridge will fluctuate to some extent depending on the sensitivity of the thermostat.
The principle of operation of temperature control devices household refrigerators are manometric type devices, which are based on the change of the pressure filler when you change its temperature (at the present time in some models of refrigerators of foreign manufacture use electronic thermostats).
The thermostat of a domestic refrigerator is a linkage from the power lever and the contact system in the electrical system of the refrigerator. On the power lever effect of the elastic element (bellows) thermocycling system and the main spring, adjustable by screw. Insulating gasket isolates the electrical circuit of the device from mechanical parts. The thermosensitive gauge-type system is composed of an elastic element of the bellows (metallic container with corrugated walls) or membrane soldered to tube him. The system is filled with a small amount of freon or chloromethyl and carefully sealed.
In the operating conditions freon is in a state of saturated vapor, the pressure of which, as you know, changes to some dependencies (for this pair) from its temperature. The liquid phase of the freon is at the end of the tube. This part of the tube, especially in place of the section of liquid and vapor refrigerant that reacts to temperature change, and it is placed a controlled cooled environment of the object.
The operation of the thermostat.
When the temperature of the tube will decrease the saturated vapor pressure Termosistem. Under the influence of the main springs of the corrugations of the bellows will be compressed and force the lever will turn on its axis, causing the contacts will open. With increasing temperature, the vapor pressure will increase accordingly. Overcoming the resistance of the spring, the corrugations of the bellows will expand and the handle will turn in the opposite direction, and the contacts will be closed.
From this it follows that the set temperature at which to open contacts, depends on the spring force. So, with a smaller force of the main spring contacts will be opened at a correspondingly lower pressure of vapor in thermococcus system and therefore at a lower temperature.
On the contrary, for higher temperatures, the spring force should be large. In this case, the spring must overcome the greater resistance of the bellows, as at a higher temperature will be greater than the vapor pressure of freon in the system thermococcus. Thus, to change the set temperature it is necessary to change the force of the main spring. Practically this is accomplished by the regulator handle, turning of which varies the tension of the spring.
The main elements of the thermostat.
In domestic refrigerators use thermostats of different designs, but some of their elements perform quite certain functions, the same for all designs.
Node sharp breaking of the contacts prevents the contacts of the thermostat from burning when opening. In the above diagram thermostat to simplify the movable contact is placed on the power lever, which act directly on the bellows and the main spring. With this arrangement, the movable contact is inevitably a strong erosion of the contacts and rapid failure. The reason is that an electric circuit by opening contacts will occur slowly in accordance with the movement of the lever, which, in turn, is determined by the slow temperature change and, accordingly, the vapor pressure of the freon in the system thermocycling. In addition, such an arrangement of the movable contact, a slight rotation of power lever will be immediately to release or close the contacts, I often break the chain. Node sharp breaking of the contacts eliminates these disadvantages. In this case, the movable contact is located on the other lever (plate) connected to the power lever special rocker spring. When you turn the power lever to certain provisions of the lever with the contact will remain stationary while the rocker spring will dramatically change its position and the contacts abruptly opens (or closes).
A unit change in temperature is a device, which alter the tension of the main spring. In some thermostats the tension of the spring change the rotation of the screw which moves the nut rests on the end face of the spring, in other ― the rotation of the roller pressed on it with a profile Cam which acts on the spring. Screw (platen) rotate the handle having a pointer for installing it in a certain position on the scale of the instrument.
Heat-sensitive system is a sensor responsive to temperature change in the test object and the acting on the contact system of the device.
The end portion of the tube, sensitive to temperature change, in a variety of thermostats may differ, which depends mainly on the level of the liquid phase of freon in it. With a small inner diameter tube or a relatively large amount of freon in the receiver when the level of the liquid phase exceeds 80 ... .100 mm, to provide such length tight fit of the tube to the wall of the evaporator difficult. In these cases, the end of the tube curl into a spiral, bend the knee or the solder cartridge is greater than that of the tube inner diameter.
The configuration node of the differential serves to regulate the magnitude of the differential. Differential of thermostat is called a temperature difference between the opening and closing of the contacts (with a certain tension of the main spring). The smaller the differential of the device, especially in narrow limits will be maintained at the set temperature. Temperature control in household refrigerators this node is used only for factory setting of the device. In many designs it is missing.
Differential change with the screw, which, being limit
