CN210039324U - Temperature control circuit teaching experiment device - Google Patents

Abstract

The utility model relates to a teaching aid technical field discloses a control by temperature change circuit teaching experiment device. Including experiment main control system and temperature regulation apparatus, experiment main control system includes control panel, and the control panel reverse side is equipped with electric elements, openly is equipped with the mounting hole, covers the copper foil in the mounting hole, and the copper foil is connected with electric elements. The temperature adjusting device comprises a water level sensor, a temperature sensor, a heater and a container, the container is provided with a clamping device, the water level sensor is installed on the clamping device, a spherical surface hollowed-out support is installed on the periphery of the temperature sensor, the spherical surface hollowed-out support is hollow inside, and balance weight particles are filled in the spherical surface hollowed-out support. The utility model discloses can demonstrate control by temperature change circuit theory of operation, can train student's manual wiring ability, help the student master sensor principle, electrician's electronic technology knowledge, temper the practise skill, train student and synthesize the application ability. The experimental result is clear directly perceived, and the student of being convenient for observes, improves learning efficiency. The water level sensor is suitable for various water level sensors, and is simple and flexible to operate.

Description

Temperature control circuit teaching experiment device

Technical Field

The utility model relates to a teaching aid technical field has especially related to a design of control by temperature change circuit teaching experiment device.

Background

The current traditional teaching mode can not adapt to the requirement of quality education step by step, and students do not understand the theory thoroughly, resulting in low efficiency of practical operation. The integrated teaching mode is getting more and more extensive popularization, but faces the problems of lack of teaching experimental equipment and poor comprehensive application effect of the existing equipment. For example, patent publication No. CN201810648741.9 discloses an integrated operational amplifier circuit experimental board, which includes a substrate and an electrical element disposed on the substrate; mounting holes are formed in corresponding pins of each electrical element, and gold-plated wire holders matched with the mounting holes are arranged on the mounting holes; the gold-plated wire holders are connected through the patch cords to realize the electrical conduction between the corresponding electrical elements. This patent can be used for teaching demonstration and student's exercise, but the experimental result is circuit parameter, and unable visual observation to the student that the learning level is lagging, the device operation degree of difficulty is big, difficultly obtains correct result, when the experiment goes wrong, and the troubleshooting mistake is also very difficult. The method is not attractive to students and can not improve the learning interest of the students. In view of the above disadvantages, it is necessary to design an experimental device with intuitive result and easy operation, which is suitable for course teaching of electromechanical major electrical and electronic technology, sensor technology, etc. Temperature is a major controlled parameter in industrial objects and is a common process variable because it directly affects physical and chemical processes such as combustion, chemical reactions, fermentation, baking, calcination, distillation, concentration, extrusion, crystallization, and air flow. In life or industrial production process, the change of temperature can affect certain detail links of life and production to different degrees, so that timely temperature control has important significance, and a simple temperature control circuit can be used as a sample for teaching.

SUMMERY OF THE UTILITY MODEL

The utility model discloses to the poor shortcoming of teaching achievement among the prior art, provide a control by temperature change circuit teaching experimental apparatus.

The utility model provides an adopt the control by temperature change circuit as the example, the control by temperature change circuit structure is clear, and the function of each part of circuit is differentiateed easily, and the student understands easily. The experimental result is more directly perceived, can direct observation, and the student of being convenient for contrasts, improves learning efficiency. This design has still utilized different kinds of centre gripping equipment fixing level sensor, is applicable to multiple type of sensor. And the spherical hollow support is adopted to achieve the purpose of suspending the temperature sensor in water, the measurement result is more accurate, and meanwhile, the support can also protect the sensor, so that the sensor is prevented from being in contact with a heater or other sensors to cause damage.

In order to solve the technical problem, the utility model discloses a following technical scheme can solve:

a temperature control circuit teaching experiment device comprises an experiment control host and a temperature adjusting device, wherein the experiment control host comprises a control panel, a plurality of electric elements are arranged on the reverse side of the control panel, mounting holes corresponding to pins of the electric elements are formed in the front side of the control panel, copper foils cover the inner surfaces of the mounting holes and are connected with the pins of the electric elements corresponding to the mounting holes, and the copper foils in different mounting holes are not connected with each other; the front surface of the control panel is divided into 5 areas which are a power supply circuit area, a sensor circuit area, an amplification and comparison circuit area, a control circuit area and an execution circuit area respectively; the temperature adjusting device comprises a water level sensor, a temperature sensor, a heater and a container for containing liquid, the container is provided with a clamping device, the water level sensor is arranged on the clamping device, the temperature sensor is arranged in the container, and the heater is wrapped on the outer surface of the container or placed in the container; the spherical surface hollowed-out support is installed on the periphery of the temperature sensor, the spherical surface hollowed-out support is hollow inside, and balance weight particles are filled in the spherical surface hollowed-out support.

The experimental requirement is to design a circuit structure which can keep the water in the container at a certain temperature, and the teaching content of the design comprises a power supply circuit, a sensor circuit, an amplifying and comparing circuit, a control circuit and an execution circuit. The power supply circuit is responsible for power supply of the whole circuit, the sensor circuit converts a temperature signal into a weak voltage to be output, the amplifying and comparing circuit amplifies the weak signal of the temperature sensor into a higher output to be compared with the voltage, the control circuit processes the output obtained by the comparing circuit to obtain a control signal and realize corresponding protection, and the execution circuit drives, controls and indicates the heating circuit according to the output of the control circuit. The spherical surface hollow support is wrapped on the periphery of the temperature sensor, the temperature sensor is located in the position of the spherical center of the support, the temperature sensor is not in contact with the support, the temperature sensor is in contact with water through the hollow part, and the support is fixedly connected with the surface of a lead connected with the temperature sensor. The weighted particles inside the stent are used for adjusting specific gravity so that the stent can be suspended in water, and the material of the stent is a heat-resistant organic material with density lower than that of water, such as heat-resistant plastic or an inflatable air column bag.

Preferably, the clamping device comprises a first vertical rod and a second horizontal rod, the first vertical rod is fixedly connected with the second horizontal rod, the first vertical rod is vertical to the bottom of the container, and the second horizontal rod is vertical to the first vertical rod; the second cross rod is provided with a clamp used for being connected with the water level sensor; first montant includes dead lever and telescopic link, and the telescopic link is equipped with the recess that corresponds with the dead lever, and the telescopic link cover is equipped with the tightening bolt on the telescopic link on the dead lever, and the tightening bolt passes telescopic link recess inner wall and dead lever surface contact. The clamping device is suitable for common straight rod-shaped water level sensors on the market, and the sensors are very long and large in size, so that the clamping device higher than the container is required to be fixed.

Preferably, the clamping device comprises a silica gel belt with two ends fixed on the inner wall of the container and a positioning piece used for being connected with the water level sensor, the positioning piece is fixed on the silica gel belt, and the positioning piece is a clamp or a belt buckle. This kind of clamping device is used for the water level sensor who uses commonly when teaching experiment, for example the electrode slice, this kind of sensor volume is less, and need immerse the aquatic, consequently adopts the silica gel area as "track", and the setting element is as "vehicle", and the setting element can move or dismouting at any time on the silica gel area, reaches the purpose that conveniently changes the sensor position.

Preferably, a direct current 24V power supply, a three-terminal regulator, a switch S1, capacitors C1, C2, C3 and C4 and a light emitting diode D1 are arranged on the reverse side of the power circuit region. In order to ensure the safety of the experiment, a main power supply adopts 24V direct current for power supply. In order to obtain 5V voltage, a 7805 three-terminal voltage regulator is adopted for voltage reduction. S1 is a main power switch, C1, C2, C3 and C4 are filter capacitors, and D1 is a power-on indicator lamp.

Preferably, the reverse side of the sensor circuit area is provided with a connecting terminal of a temperature sensor, a connecting terminal of a water level sensor and a resistor R2; and a wiring terminal of the temperature sensor is connected with the temperature sensor, and a wiring terminal of the water level sensor is connected with the water level sensor. The sensor circuit is divided into two parts, namely a temperature sensor part and a water level sensor part. The temperature measurement adopts an LM35 sensor, LM35 is a temperature sensor produced by American national semiconductor company, the output voltage of LM35 is in direct linear relation with a temperature scale in centigrade, when the temperature is 0 ℃, the output voltage of LM35 is 0V, and the output voltage increases by 10mV when the temperature rises by 1 ℃ every time. Assuming that the current temperature is 25 ℃, the output voltage is 250 mV. The water level detection sensor has a low on-resistance, which is much lower than the value of R2.

Preferably, an operational amplifier U3A, voltage comparators U4A and U4B, potentiometers RV1 and RV2, and resistors R3, R4, R5 and R6 are arranged on the reverse side of the amplifying and comparing circuit region. The front stage U3A adopts LM358 chip to form an amplifying circuit, and the rear stages U4A and U4B adopt LM339 chip to form two comparing circuits. The two latter comparison circuits are respectively an upper limit comparator U4: a and lower limit comparator U4: and B, comparing the temperature measured value with a set value. The RV1 and RV2 potentiometers can be respectively adjusted to obtain voltages UH and UL as non-inverting input voltages of the RV1 and the RV2 potentiometers, wherein UH corresponds to the upper limit voltage of the temperature, UH corresponds to the lower limit voltage of the temperature, and UH is greater than UL.

Preferably, nand chips U5A, U5B, U5C and U5D, resistors R7, R8 and R10, and a transistor Q1 are provided on the reverse side of the control circuit region. The control circuit needs to achieve the functions of control and protection and can be divided into two parts, namely a latch circuit and a protection circuit according to the functions. The protection circuit is to process the input water level signal and control the output to realize the function of preventing the heater from being dry-burned.

Preferably, a connecting terminal of the heater, a triode Q2, a relay KA, a freewheeling diode D2, a light emitting diode D3 and a resistor R10 are arranged on the back surface of the executive circuit region; the wiring terminal of the heater is connected with the heater. Because the output power of the front-stage circuit is limited, the triode Q2 is used for driving a coil of the relay KA, the D2 is a freewheeling protection diode, and the D3 is a heating work indicator lamp. In order to ensure the safety of the experiment, the heating circuit adopts low-voltage 24V power supply for heating.

Preferably, the control panel is provided with symbol marks corresponding to the electric components on the front surface. The student can realize the circuit intercommunication through grafting circuit line according to specific circuit schematic diagram, can be through instrument and meter equipment such as universal meter, oscilloscope, examination lamp in addition, real-time measurement circuit state, debugging circuit.

The utility model discloses owing to adopted above technical scheme, have apparent technological effect: can demonstrate control by temperature change circuit theory of operation, can train the student and hand the wiring ability, help the student master sensor principle, electrician's electronic technology knowledge, temper the practise skill, train student's comprehensive application ability. The experimental result is clear directly perceived, and the student of being convenient for observes, improves learning efficiency. The water level sensor is suitable for various water level sensors, and is simple and flexible to operate.

Drawings

Fig. 1 is a schematic structural diagram of embodiment 1 of the present invention.

Fig. 2 is a schematic diagram of a control panel structure according to embodiment 1 of the present invention.

Fig. 3 is a schematic structural view of a temperature adjustment device according to embodiment 1 of the present invention.

Fig. 4 is a schematic structural view of a holding device according to embodiment 1 of the present invention.

Fig. 5 is a schematic view of the spherical hollow-out bracket structure of embodiment 1 of the present invention.

Fig. 6 is a circuit diagram illustrating exemplary wiring of the power circuit region according to embodiment 1 of the present invention.

Fig. 7 is a circuit diagram of an exemplary wiring of a sensor circuit area according to embodiment 1 of the present invention.

Fig. 8 is a circuit diagram of an exemplary wiring circuit of an amplifying and comparing circuit region according to embodiment 1 of the present invention.

Fig. 9 is a circuit diagram illustrating exemplary wiring of the control circuit area according to embodiment 1 of the present invention.

Fig. 10 is a circuit diagram illustrating exemplary wiring of an execution circuit region according to embodiment 1 of the present invention.

Fig. 11 is an exemplary circuit diagram of the overall circuit wiring according to embodiment 1 of the present invention.

Fig. 12 is a schematic structural view of a holding device according to embodiment 2 of the present invention.

Fig. 13 is a schematic diagram of the heater position according to embodiment 3 of the present invention.

The names of the parts indicated by the numerical references in the above figures are as follows: the device comprises an experiment control host, a temperature adjusting device, a control panel, a water level sensor, a temperature sensor, a heater, a container, a spherical surface hollowed-out support, a mounting hole, a symbol mark 112, a clamping device 241, a counterweight particle 251, a first vertical rod 2411, a second horizontal rod 2412, a 2413-clamp, a 2499-fixed rod, a 2498-telescopic rod, a 2497-groove, a 2496-screwing bolt, a 2414-silica gel belt and a 2415-positioning piece 1.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.

Example 1

As shown in fig. 1 to 11, a temperature control circuit teaching experimental device includes an experimental control host 1 and a temperature adjusting device 2, the experimental control host 1 includes a control panel 11, a plurality of electrical components are disposed on the reverse side of the control panel 11, mounting holes 111 corresponding to pins of each electrical component are disposed on the front side of the control panel 11, copper foils cover the inner surfaces of the mounting holes 111, the copper foils are connected with the pins of the electrical components corresponding to the mounting holes 111, and the copper foils in different mounting holes 111 are not connected to each other; the front surface of the control panel 11 is divided into 5 areas, namely a power supply circuit area, a sensor circuit area, an amplification and comparison circuit area, a control circuit area and an execution circuit area; the temperature adjusting device 2 comprises a water level sensor 21, a temperature sensor 22, a heater 23 and a container 24 for containing liquid, the container 24 is provided with a clamping device 241, the water level sensor 21 is installed on the clamping device 241, the temperature sensor 22 is installed in the container 24, and the heater 23 is placed in the container 24; the spherical hollow bracket 25 is installed on the periphery of the temperature sensor 22, and the spherical hollow bracket 25 is hollow and filled with the balance weight particles 251. The control panel 11 has symbol marks 112 corresponding to the electric components on the front surface.

The clamping device 241 comprises a first vertical rod 2411 and a second horizontal rod 2412, the first vertical rod 2411 and the second horizontal rod 2412 are fixedly connected, the first vertical rod 2411 is vertical to the bottom of the container 24, and the second horizontal rod 2412 is vertical to the first vertical rod 2411; a clamp 2413 for connecting with the water level sensor 21 is arranged on the second cross rod 2412; the first vertical rod 2411 comprises a fixed rod 2499 and a telescopic rod 2498, the telescopic rod 2498 is provided with a groove 2497 corresponding to the fixed rod 2499, the telescopic rod 2498 is sleeved on the fixed rod 2499, the telescopic rod 2498 is provided with a tightening bolt 2496, and the tightening bolt 2496 penetrates through the inner wall of the groove 2497 of the telescopic rod 2498 to be in surface contact with the fixed rod 2499.

The reverse side of the power circuit region is provided with a direct current 24V power supply, a three-terminal regulator, a switch S1, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4 and a light-emitting diode D1.

The reverse side of the sensor circuit area is provided with a temperature sensor 22 connecting terminal, a water level sensor 21 connecting terminal and a resistor R2; the temperature sensor 22 terminal is connected to the temperature sensor 22, and the water level sensor 21 terminal is connected to the water level sensor 21. The sensor circuit is divided into two parts, a temperature sensor 22 and a water level sensor 21. The temperature sensor 22 adopts an LM35 sensor, two ends of the LM35 sensor are connected to the terminals of the temperature sensor 22, the water level sensor 21 selects two electrodes and an R2 resistor, and the two electrodes are connected to the terminals of the water level sensor 21. The switch S2 is used to simulate the water level condition, and its on resistance is low, much lower than the value of R2. When the water level is lower than the limit level, S2 is disconnected, a Us1 is pulled low through R2, and the output is low level 0; when the water level is higher than the limit level, S2 is closed and the Us1 output is high level 1.

An operational amplifier U3A, voltage comparators U4A and U4B, potentiometers RV1 and RV2, and resistors R3, R4, R5 and R6 are arranged on the reverse side of the amplifying and comparing circuit region. The front stage LM358 constitutes an amplifying circuit, and the rear stage LM339 constitutes two comparing circuits. Because the output voltage signal of the front-stage sensor circuit is weak and is not suitable for direct comparison and judgment, amplification is needed, the amplification adopts a same-phase amplification circuit, and the output and input relation of the same-phase amplification circuit is Uo1 to 10 Uout.

Two comparison circuits in the back stage are simultaneously arranged, and are respectively an upper limit comparator U4: a and lower limit comparator U4: and B. The RV1 and RV2 potentiometers are respectively regulated to obtain voltages UH and UL as the in-phase input voltages of the RV1 and the RV2 potentiometers, wherein UH corresponds to the upper limit voltage of the temperature, UH corresponds to the lower limit voltage of the temperature, and UH is greater than UL. When the temperature exceeds the lower limit, UO1> UL, the output UO3 is high level 1, otherwise the output UO3 is low level 0; when the temperature exceeds the upper limit, Uo1> UH, the output Uo2 is high level 1, otherwise, it is low level 0.

The reverse side of the control circuit area is provided with NAND gate chips U5A, U5B, U5C and U5D, resistors R7, R8 and R10 and a triode Q1. The control circuit is divided into a latch circuit and a protection circuit. The latch circuit mainly comprises 3 NAND gates and a resistor R7. When Uo2 ═ Uo3 ═ 0, Uo4 is achieved with a set of 0; uo4 retention is achieved when Uo2 is 1 and Uo3 is 0; uo4 is set to 1 when Uo 2-Uo 3-1.

The protection circuit processes the input water level signal and controls the output of the UO5, so that the effect of preventing subsequent circuits from heating and burning is achieved. The nand gate U5: d forms an inverter to obtain a Us2 output. When the water level is proper, Us1 is 1, Us2 is 0, and the triode Q1 is cut off, so that the output Uo5 is equal to Uo4, when the water level is too low, Us1 is 0, Us2 is 1, the triode Q1 is saturated, and Uo5 is 0.

The reverse side of the executive circuit region is provided with a heater 23 connecting terminal, a triode Q2, a relay KA, a freewheeling diode D2, a light emitting diode D3 and a resistor R10; the heater 23 terminal is connected to the heater 23. The circuit diagram is executed. The execution circuit mainly comprises a triode Q2, a relay KA and a heater 23. RL is identified as the heater number in the figure. Since the output power of the front-stage circuit is limited, Q2 is used to drive the KA coil, D2 is a freewheeling protection diode, and D3 is a heating operation instruction. When UO5 is 1, the KA coil is electrified, carries out heating control, and when UO5 is 0, the KA coil loses the electricity, stops heating, for guaranteeing experiment safety, heating circuit adopts the power supply of low pressure 24V to heat.

Through the effective cooperation of circuits of all stages. When the temperature is lower than the lower limit, heating control is performed, and heating is continuously kept until the temperature is higher than the upper limit, and heating is stopped. When the temperature is lower than the lower limit again, the heating is started again, the circulation is repeated in this way, the temperature control is realized, and the temperature control range can be realized by adjusting RV1 and RV 2.

Example 2

As shown in fig. 12, in the temperature control circuit teaching experiment apparatus, the clamping device 241 includes a silica gel belt 2414 with two ends fixed on the inner wall of the container 24 and a positioning member 2415 for connecting with the water level sensor 21, the positioning member 2415 is fixed on the silica gel belt 2414, and the positioning member 2415 or the belt buckle. The rest is the same as example 1.

Example 3

As shown in fig. 13, a temperature control circuit teaching experiment device, a heater 23 is wrapped on the outer surface of a container 24. The rest is the same as example 1.

In short, the above description is only a preferred embodiment of the present invention, and all the equivalent changes and modifications made in accordance with the claims of the present invention should be covered by the scope of the present invention.

Claims (9)

1. The utility model provides a control by temperature change circuit teaching experimental apparatus, includes experiment control host computer (1) and temperature regulation apparatus (2), its characterized in that: the experiment control host (1) comprises a control panel (11), a plurality of electrical elements are arranged on the reverse side of the control panel (11), mounting holes (111) corresponding to pins of the electrical elements are formed in the front side of the control panel (11), copper foils cover the inner surfaces of the mounting holes (111), the copper foils are connected with the pins of the electrical elements corresponding to the mounting holes (111), and the copper foils in different mounting holes (111) are not connected with each other; the front surface of the control panel (11) is divided into 5 areas which are a power circuit area, a sensor circuit area, an amplification and comparison circuit area, a control circuit area and an execution circuit area respectively; the temperature adjusting device (2) comprises a water level sensor (21), a temperature sensor (22), a heater (23) and a container (24) for containing liquid, the container (24) is provided with a clamping device (241), the water level sensor (21) is installed on the clamping device (241), the temperature sensor (22) is installed in the container (24), and the heater (23) is wrapped on the outer surface of the container (24) or placed in the container (24); the spherical surface hollowed-out support (25) is installed on the periphery of the temperature sensor (22), and the spherical surface hollowed-out support (25) is hollow inside and filled with balance weight particles (251).

2. The temperature control circuit teaching experiment device of claim 1, wherein: the clamping device (241) comprises a first vertical rod (2411) and a second horizontal rod (2412), the first vertical rod (2411) and the second horizontal rod (2412) are fixedly connected, the first vertical rod (2411) is vertical to the bottom of the container (24), and the second horizontal rod (2412) is vertical to the first vertical rod (2411); a clamp (2413) used for being connected with the water level sensor (21) is arranged on the second cross rod (2412); the first vertical rod (2411) comprises a fixed rod (2499) and a telescopic rod (2498), the telescopic rod (2498) is provided with a groove (2497) corresponding to the fixed rod (2499), the telescopic rod (2498) is sleeved on the fixed rod (2499), the telescopic rod (2498) is provided with a tightening bolt (2496), and the tightening bolt (2496) penetrates through the inner wall of the groove (2497) of the telescopic rod (2498) to be in surface contact with the fixed rod (2499).

3. The temperature control circuit teaching experiment device of claim 1, wherein: the clamping device (241) comprises a silica gel belt (2414) with two ends fixed on the inner wall of the container (24) and a positioning piece (2415) used for being connected with the water level sensor (21), the positioning piece (2415) is fixed on the silica gel belt (2414), and the positioning piece (2415) is a clamp or a buckle.

4. The temperature control circuit teaching experiment device of claim 1, wherein: the reverse side of the power circuit region is provided with a direct current 24V power supply, a three-terminal regulator, a switch S1, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4 and a light-emitting diode D1.

5. The temperature control circuit teaching experiment device of claim 1, wherein: the reverse side of the sensor circuit area is provided with a connecting terminal of a temperature sensor (22), a connecting terminal of a water level sensor (21) and a resistor R2; a wiring terminal of the temperature sensor (22) is connected with the temperature sensor (22), and a wiring terminal of the water level sensor (21) is connected with the water level sensor (21).

6. The temperature control circuit teaching experiment device of claim 1, wherein: an operational amplifier U3A, voltage comparators U4A and U4B, potentiometers RV1 and RV2, and resistors R3, R4, R5 and R6 are arranged on the reverse side of the amplifying and comparing circuit region.

7. The temperature control circuit teaching experiment device of claim 1, wherein: the reverse side of the control circuit area is provided with NAND gate chips U5A, U5B, U5C and U5D, resistors R7, R8 and R10 and a triode Q1.

8. The temperature control circuit teaching experiment device of claim 1, wherein: the reverse side of the execution circuit region is provided with a connecting terminal of a heater (23), a triode Q2, a relay KA, a freewheeling diode D2, a light-emitting diode D3 and a resistor R10; the terminal of the heater (23) is connected with the heater (23).

9. The temperature control circuit teaching experiment device of claim 1, wherein: the front surface of the control panel (11) is provided with a symbol mark (112) corresponding to the electric element.

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