Electronic temperature controller

Electronic temperature controller

The controller with temperature regulation function designed and produced by using circuit electronic technology

Electronic temperature controller is a controller with temperature regulation function designed and produced by using circuit and electronic technology, mainly used for temperature control of electric heating and water heating. It has the characteristics of convenient operation and high control precision.

Electronic temperature controller Application Temperature control principle of electric heating and water heating Circuit Electronic technical characteristics Easy operation and high control accuracy Main categories Five types of measurement methods Resistance temperature sensing method

1 Electronic temperature controller

2 Classification of temperature controllers

The electronic temperature controller (resistance type) is measured by means of resistance temperature sensing. Generally, platinum wire, copper wire, tungsten wire and semiconductor (thermistor, etc.) are used as temperature measuring resistors. Each of these resistors has its own advantages. The sensors of household air conditioners are mostly thermistors.

The thermistor temperature controller is made according to the principle of Wheatstone bridge, which is a Wheatstone bridge. Connect power E at both ends of BD. According to Kirchhoff's law, when the resistance of the bridge R1 × R4=R2 × When R3 is applied, the potential of two points A and C is equal, there is no current flowing between the output terminals A and C. The impedance R1 of the thermistor changes with the increase or decrease of the ambient temperature, which destroys the balance, and there is an output current between ACs. Therefore, when forming the temperature controller, it is easy to change the temperature adjustment range and working temperature by selecting an appropriate thermistor.

Classification of temperature controllers

According to the manufacturing principle of the temperature controller, the temperature controller is divided into:

1、 Snap type temperature controller: the models of various snap type temperature controllers are collectively referred to as KSD, such as KSD301, KSD302, etc. This temperature controller is a new product of bimetallic temperature controller. It is mainly used as a series connection with thermal fuse when various electric heating products have overheating protection. The snap type temperature controller is used as a primary protection. The thermal fuse is used as a secondary protection when the electric heating element is overheated due to the loss or failure of the snap temperature controller, effectively preventing burning out the electric heating element and the resulting fire accident.

2、 Liquid expansion type temperature controller: refers to the physical phenomenon (volume change) that causes the material (usually liquid) in the temperature sensing part of the temperature controller to expand with heat and contract with cold when the temperature of the controlled object changes, and the membrane box connected with the temperature sensing part will expand or contract. With the lever principle, it drives the on-off action of the switch to achieve the goal of constant temperature. The liquid expansion temperature controller has the characteristics of accurate temperature control, stability and reliability, small start stop temperature difference, large control temperature control adjustment range, large overload current, etc. The liquid expansion temperature controller is mainly used in the household appliance industry, electric heating equipment, refrigeration industry and other temperature control fields.

3、 The pressure type temperature controller is modified to change the controlled temperature change into the change of space pressure or volume through the closed temperature bulb and capillary filled with temperature sensing working medium. When the temperature setting value is reached, the contact is automatically closed through the elastic element and quick instantaneous mechanism to achieve the purpose of automatic temperature control. The utility model is composed of a temperature sensing part, a temperature setting main part, a micro switch for opening and closing, an automatic damper, etc. The pressure type temperature controller is applicable to refrigeration appliances (such as refrigerators, freezers, etc.) and heat generators.

The above are common mechanical temperature controllers.

4、 Electronic temperature controller and electronic temperature controller (resistance type) are measured by means of resistance temperature sensing. Platinum wire, copper wire, tungsten wire and thermistor are generally used as temperature measuring resistors. Each of these resistors has its own advantages. Most household air conditioners use thermistor type. The electronic temperature controller has the advantages of stability and small size, and is used in more and more fields in the 21st century.

thermostat

5、 Digital temperature controller: digital electronic temperature controller is an accurate temperature detection controller, which can conduct digital quantitative control of temperature. The temperature controller generally uses NTC thermal sensors or thermocouples as temperature detection elements. Its principle is to design NTC thermal sensors or thermocouples into corresponding circuits. NTC thermal sensors or thermocouples will change with temperature changes, which will produce corresponding voltage and current changes. Then, the changed voltage and current will be detected, quantized and displayed through the microcontroller, and the corresponding control will be performed. The digital temperature controller has the characteristics of high accuracy, good sensitivity, intuitiveness and convenient operation.