CN204303228U - Thermistor characteristic and application experiment instrument - Google Patents

Abstract

The utility model relates to a thermal resistance characteristic and application experiment instrument, which belongs to the field of physical experiment instruments. The circuit is composed of two parts, the first part is a main circuit, and the second part is a circuit for adjusting temperature and a small electric fan. It is characterized in that it is rectangular The frame is fixed vertically on the demo board. The thermistor and digital thermometer probe are placed on the upper panel inside the rectangular frame, and the 12V heater is fixed on the lower panel inside the rectangular frame. Adjusting the size of the thermostat potentiometer can change the temperature, digital The thermometer is used to display the temperature, the mA meter is used to demonstrate the change of the current in the thermistor, the ohmmeter is used to demonstrate the change of the resistance of the thermistor, the rotation and non-rotation of the small electric fan is used to demonstrate the application of the thermistor, The utility model has the advantages and positive effects: the demonstration image is intuitive, it can not only demonstrate the characteristics of the thermistor, but also demonstrate the application of the thermistor in daily life, it can be used as a demonstration, and it can also be used as a group experiment instrument for students .

Description

Thermistor characteristics and application tester

technical field

The utility model relates to a thermistor characteristic and application experiment instrument, which belongs to the field of physics teaching instruments.

Background technique

At present, in physics teaching, the demonstration instruments about the characteristics of thermistors can only demonstrate the characteristics of thermistors, but cannot demonstrate the application of thermistors in daily life. It can demonstrate the characteristics of the thermistor and the application of the thermistor in daily life. It can be used as a teaching demonstration and as an experimental instrument for students in groups.

Utility model content

The purpose of this utility model is to provide a thermistor characteristic and application experiment instrument, which can not only demonstrate the characteristics of thermistor, but also demonstrate the application of thermistor in daily life.

The purpose of this utility model is achieved in this way: the circuit is composed of two parts, the first part is the main circuit, the second part is the temperature adjustment and small electric fan circuit, the main circuit is composed of DC power supply E, switch S ₁ , switch S ₂ , Thermistor R _T , adjustable resistor R ₁ , resistor R ₂ , resistor R ₃ , integrated block I ₁ , DC electromagnetic relay KA coil, capacitor C ₁ , capacitor C ₂ , capacitor C ₃ , diode VD, milliampere meter mA , ohmmeter Ω, temperature adjustment and small electric fan circuit consists of 220V AC power supply, transformer T, rectifier circuit B, capacitor C ₄ , integrated block I ₂ , switch S ₃ , resistor R ₄ , thermostat potentiometer R ₅ , 12V The heating plate L, the normally open contact of the DC electromagnetic relay KA, and the small electric fan M are composed. The positive pole of the DC power supply E is connected to one end of the switch _S1 , the other end of the switch _S1 is connected to the positive pole of the capacitor C1, and the negative pole of the capacitor _C1 is connected to the positive pole of the capacitor _C1 . The negative pole of the DC power supply E, the adjustable resistor R ₁ , milliampere meter mA, thermistor R _T , and resistor R ₂ are connected in series to both ends of the capacitor C ₁ in parallel, and the ohmmeter Ω is connected in parallel to the thermistor R _T One end of switch _S2 is connected to the other end of switch _S1 , the other end of switch _S2 is connected to one end of resistor _R3 , pin 4 and pin 8 of integrated block _I1 , and pin ₂ of integrated block I1 is connected to Between the adjustable resistor _R1 and the milliampere meter mA, the other end of the resistor _R3 is simultaneously connected to pins 6 and 7 of the integrated block _I1 and the positive pole of the capacitor _C3 , and pin 3 of the integrated block _I1 is simultaneously connected to the DC electromagnetic One end of the relay KA coil, the negative pole of the diode VD, the other end of the DC electromagnetic relay KA coil, the positive pole of the diode VD, and the negative pole of the capacitor _C3 are connected to the negative pole of the DC power supply E, and one end of the capacitor _C2 is connected to the integrated block I Pin 5 of ₁ , the other end of capacitor C ₂ is connected to the negative pole of DC power supply E, pin 1 of integrated block I ₁ is connected to the negative pole of DC power supply E, both ends of the 220V winding of transformer T are connected to 220V AC power supply, and the input of rectifier circuit B The terminals are connected to both ends of the 12V winding of the transformer T, the input terminal of the integrated block _I2 is connected to the output terminal of the rectifier circuit B, the switch _S3 , the resistor _R4 , the thermostat potentiometer _R5 , and the 12V heating sheet L are connected in series At the output end of the integrated block _I2 , the normally open contacts of the small electric fan M and the DC electromagnetic relay KA are connected in series to the two ends of the 220V winding of the transformer T. The panel is composed of a rectangular frame vertically fixed on the demo board, the thermistor and digital thermometer probe are placed on the upper panel inside the rectangular frame, the 12V heating sheet L is fixed on the lower panel inside the rectangular frame, and the thermostat potentiometer R ₅ is adjusted The temperature can be changed by changing the size of the switch S _{1 and the switch S 2. By changing the on and off states of the switch S 1} and the switch S ₂ , it can not only demonstrate the characteristics of the thermistor, but also demonstrate the application of the thermistor in daily life. The integrated block I ₁ uses NE555 , Manifold I ₂ with a three-terminal regulator 7812, digital The thermometer is used to display the temperature received by the thermistor _RT , the milliampere meter mA is used to demonstrate the change of the current in the thermistor _RT , the ohmmeter Ω is used to demonstrate the change of the resistance of the thermistor _RT , and the small electric fan M The rotation and non-rotation are used to demonstrate the application of thermistor R _T.

Due to the adoption of the above technical solution, the utility model has the advantages and positive effects: it can not only demonstrate the characteristics of the thermistor, but also demonstrate the application of the thermistor in daily life, the structure is simple, intuitive and accurate, and the operation and demonstration are convenient.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

Fig. 1, Fig. 2 are circuit principle diagrams of the present utility model.

Fig. 3 is a schematic diagram of the overall structure of the utility model.

In the figure E. DC power supply S ₁ . Switch S ₂ . Switch R _T . Thermistor R ₁ . Adjustable resistance R ₂ . Resistance R ₃ . Resistance I ₁ . Manifold KA. DC electromagnetic relay (coil, normally open contact Point) C _1. Capacitor C _2. Capacitor C _3. Capacitor VD. Diode mA. Milliampmeter Ω. Ohmmeter T. Transformer M. Small electric fan B. Rectifier circuit C _4. Capacitor I _2. Three-terminal regulator 7812 S _3. Switch R _4. Resistor R _5. Temperature potentiometer L. 12V heater W _1. Digital thermometer W _2. Digital thermometer probe 1. Base 2. Demonstration board 3. Rectangular frame

Detailed ways:

In Figure 1, the positive pole of the DC power supply (E) is connected to one end of the switch (S ₁ ), the other end of the switch (S ₁ ) is connected to the positive pole of the capacitor (C ₁ ), and the negative pole of the capacitor (C ₁ ) is connected to the DC power supply (E ), the adjustable resistor (R ₁ ), (mA), thermistor (R _T ), and resistor (R ₂ ) are connected in series and connected in parallel at both ends of the capacitor (C ₁ ), and the ohmmeter (Ω) Connected in parallel to both ends of the thermistor ( _RT ), one end of the switch (S ₂ ) is connected to the other end of the switch (S ₁ ), and the other end of the switch (S ₂ ) is connected to one end of the resistor (R ₃ ). (I ₁ ) pin 4 and pin 8, pin 2 of the integrated block (I ₁ ) is connected between the adjustable resistor (R ₁ ) and the milliampere meter (mA), and the other end of the resistor (R ₃ ) is connected to the integrated The 6 pins and 7 pins of the block (I ₁ ), the positive pole of the capacitor (C ₃ ), the 3 pins of the integrated block (I ₁ ) are simultaneously connected to one end of the coil of the DC electromagnetic relay (KA), the negative pole of the diode (VD), and the DC electromagnetic The other end of the relay (KA) coil, the positive pole of the diode (VD), and the negative pole of the capacitor (C ₃ ) are connected to the negative pole of the DC power supply (E), and one end of the capacitor (C ₂ ) is connected to the ₅ of the integrated block I 1 pin, the other end of the capacitor (C ₂ ) is connected to the negative pole of the DC power supply (E), and pin 1 of the integrated block (I ₁ ) is connected to the negative pole of the DC power supply (E). Manifold (I ₁ ) uses NE555.

In Figure 2, the normally open contacts of the small electric fan (M) and the DC electromagnetic relay (KA) are connected in series to both ends of the 220V winding of the transformer (T), and the two ends of the 220V winding of the transformer (T) are connected to the AC The power supply is 220V, the input terminal of the rectifier circuit (B) is connected to both ends of the 12V winding of the transformer (T), the input terminal of the integrated block (I ₂ ) is connected to the output terminal of the rectifier circuit (B), and the capacitor (C ₄ ) is connected in parallel The output terminal of the rectifier circuit (B), the switch (S ₃ ), the resistor (R ₄ ), the thermostat potentiometer (R ₅ ), and the 12V heating chip (L) are connected in series to the output terminal of the integrated block (I ₂ ).

In Figure 3, switch (S ₁ ), switch (S ₂ ), switch (S ₃ ), thermostat potentiometer (R ₅ ), DC electromagnetic relay (KA), milliampere meter (mA), ohmmeter (Ω ), a digital thermometer (W ₁ ), and a small electric fan (M) are placed on the front of the demo board (2); the rectangular frame (3) is composed of four panels perpendicular to each other, and the rectangular frame (3) is vertically fixed on the demo board (2). On the board (2), the thermistor (R _T ) and the digital thermometer probe (W ₂ ) are placed on the upper board in the rectangular frame, and the 12V heating chip (L) is fixed on the lower board in the rectangular frame (3). Adjust the size of the thermostat potentiometer (R ₅ ) to change the temperature, adjustable resistance (R ₁ ), resistance (R ₂ ), resistance (R ₃ ), resistance (R ₄ ), integrated block (I ₁ ), integrated block (I ₂ ), capacitor (C ₁ ), capacitor (C ₂ ), capacitor (C ₃ ), capacitor (C ₄ ), diode (VD), rectifier circuit (B), transformer (T) fixed on the demo board (2 ) on the opposite side.

Claims (1)

1. thermistor characteristic and an application experiment instrument, circuit is made up of two parts, and Part I is main circuit, and Part II is for regulating temperature and little fan circuit, and main circuit is by dc source E, switch S ₁, switch S ₂, thermistor R _t, adjustable resistance R ₁, resistance R ₂, resistance R ₃, integrated package I ₁, direct current electromagnetic relay KA coil, capacitor C ₁, capacitor C ₂, capacitor C ₃, diode VD, milliammeter mA, ohmmeter Ω form, and regulates temperature and little fan circuit by 220V AC power, transformer T, rectification circuit B, capacitor C ₄, integrated package I ₂, switch S ₃, resistance R ₄, temperature-adjusting potentiometer R ₅, 12V heating plate L, direct current electromagnetic relay KA normally opened contact, little electric fan M form, the positive pole of dc source E connects switch S ₁one end, switch S ₁another terminating capacitor C ₁positive pole, capacitor C ₁negative pole connect the negative pole of dc source E, adjustable resistance R ₁, milliammeter mA, thermistor R _t, resistance R ₂capacitor C is connected in parallel on after four element series connection ₁two ends, ohmmeter Ω is connected in parallel on thermistor R _ttwo ends, switch S ₂a termination switch S ₁the other end, switch S ₂the other end simultaneously connecting resistance R ₃one end, integrated package I ₁4 pin and 8 pin, integrated package I ₁2 pin be connected on adjustable resistance R ₁and between milliammeter mA, resistance R ₃the other end meet integrated package I simultaneously ₁6 pin, 7 pin, capacitor C ₃positive pole, integrated package I ₁3 pin connect one end of direct current electromagnetic relay KA coil, the negative pole of diode VD, the other end of direct current electromagnetic relay KA coil, the positive pole of diode VD, capacitor C simultaneously ₃negative pole be connected after be connected on the negative pole of dc source E, capacitor C ₂a termination integrated package I ₁5 pin, capacitor C ₂the negative pole of another termination dc source E, integrated package I ₁1 pin connect the negative pole of dc source E, two termination AC power 220V of the 220V winding of transformer T, integrated package I ₂input be connected on the output of rectification circuit, switch S ₃, resistance R ₄, temperature-adjusting potentiometer R ₅, 12V heating plate L connect after be connected on integrated package I ₂output, the two ends of the 220V winding of transformer T are connected on after the normally opened contact series connection of little electric fan M and direct current electromagnetic relay KA, it is characterized in that: rectangle frame is vertically fixed on demonstration board, thermistor, digital thermometer probe is placed on the top panel in rectangle frame, 12V heating plate L is fixed on the lower panel in rectangle frame, integrated package I ₁with TWH8751, integrated package I ₂with three terminal regulator 7812.