CN201671863U - Fan Control System - Google Patents

Abstract

The utility model relates to a fan control system, which comprises a temperature detection unit, a forward rotation drive circuit and a reverse rotation drive circuit. The forward rotation drive circuit and the reverse rotation drive circuit can respectively be in working states according to the ambient temperature detected by the temperature detection unit, and The forward rotation drive circuit and the reverse rotation drive circuit are not in working state at the same time.

Description

Fan Control System

technical field

The utility model relates to a fan control system, in particular to a fan control system which automatically controls the rotation direction of a cooling fan according to the ambient temperature.

Background technique

Various devices at present need to use fans for cooling, and the common cooling fan control system generally controls the rotation direction of the fan to be a fixed direction. For the cooling fan with fixed rotation direction, it can be divided into suction type structure and blowing type structure according to the difference of fan rotation direction forward and reverse. The cooling fan with suction structure is prone to problems such as excessive temperature inside the unit, aging of components, and unstable operation of the unit in summer, especially in hot climate areas. When the cooling fan with the blower structure is at low temperature, such as the severe winter in the north, the temperature inside the unit will be low, the control circuit and control components will freeze, and even the unit cannot work normally. Therefore, the usual control system of the fan cannot meet the ambient temperature of high temperature and low temperature at the same time, and has poor temperature adaptability and reliability.

Contents of the invention

In order to solve the problems of poor temperature adaptability and poor reliability of the prior art fan control system, it is necessary to provide a fan control system with high temperature adaptability and high reliability.

A fan control system, which includes a temperature detection unit, a forward rotation drive circuit and a reverse rotation drive circuit, the forward rotation drive circuit and the reverse rotation drive circuit can be in the working state respectively according to the ambient temperature detected by the temperature detection unit, and the forward rotation drive The circuit and the reverse drive circuit are not in working state at the same time.

A fan control system, which includes a high-temperature intermediate relay, a low-temperature intermediate relay, a forward contactor, a reverse contactor, a first temperature switch, and a second temperature switch. When either the first temperature switch or the second temperature switch is turned on , the high-temperature intermediate relay is turned on, making the forward contactor pull in, and the reverse contactor is not. When both the first temperature switch and the second temperature switch are off, the low-temperature intermediate relay is turned on, making the The contactor pulls in, and the forward rotation contactor does not pull in.

Compared with the prior art, the fan control system of the utility model controls the rotation direction of the fan motor according to the detected ambient temperature, specifically using the first and second temperature switches, forward contactors, reverse contactors, and high-temperature intermediate relays , The low-temperature intermediate relay realizes corresponding to different ambient temperatures, and the rotation direction of the fan motor is different. When the temperature is high, it rotates forward, and when the temperature is low, it reverses, so that it can adapt to the external ambient temperature, ensure the normal operation of the unit, and have better temperature adaptation. performance and high reliability.

Description of drawings

FIG. 1 is a schematic block diagram of a preferred embodiment of the fan control system of the present invention.

2-3 are schematic diagrams of the circuit structure of the fan control system shown in FIG. 1 .

FIG. 4 is a schematic diagram of a partial work flow of the fan control system shown in FIG. 1 .

Detailed ways

Please refer to FIG. 1 , which is a schematic block diagram of a preferred embodiment of the fan control system of the present invention. The fan control system 1 includes a temperature detection unit 10 , a forward drive circuit 20 , a reverse drive circuit 30 , a bypass drive circuit 40 , a fan motor 50 and a fan 60 . The temperature detection unit 10 includes at least two temperature sensors (not shown in the figure), which can detect the ambient temperature. The temperature detection unit 10 is connected to the forward rotation drive circuit 20 , the reverse rotation drive circuit 30 and the bypass drive circuit 40 . The bypass drive circuit 40 is connected to the forward rotation drive circuit 20 . The forward rotation drive circuit 20 and the reverse rotation drive circuit 30 are respectively connected to a fan motor 50 . The fan motor 50 is connected with the fan 60 for driving the fan 60 to rotate.

Referring to Fig. 2-3, the fan control system 1 is powered by an external AC voltage AC, and its AC voltage value does not exceed the safe voltage for human body. Because the temperature detection unit 10 is preferably arranged at the air inlet for detecting ambient light, it can be powered by a safe voltage to ensure personal safety. The fan control system also includes an air switch QF, which is used as the work control switch of the whole system. The fan control system 1 includes reverse contactors KM4 and KM5, high temperature intermediate relays KA3 and KA4, low temperature intermediate relays KA5, time relay KT2, bypass switch QF6 and first and second temperature switches T1 and T2, of which the forward contactor When KM5 is engaged, the fan motor 50 is controlled to rotate forward, and when the reverse contactor KM4 is engaged, the fan motor 50 is controlled to rotate reversely. .

Please also refer to FIG. 4 , which is a schematic diagram of a part of the work flow of the fan control system shown in FIG. 1 . The first temperature switch T1 of the fan control system 1 corresponds to a first predetermined value, the second temperature switch T2 corresponds to a second predetermined value, and the first predetermined value is smaller than the second predetermined value, which are respectively used to control the rotation direction of the fan at different ambient temperatures . Wherein, the first predetermined value may be 5°C, and the second predetermined value may be 35°C. Of course, according to different specific needs, the first predetermined value and the second predetermined value can be changed accordingly.

Taking the case where the first preset value is set to 5°C and the second preset value is 35°C as an example, the specific workflow of the fan control system 1 is described as follows:

The fan control system 1 is connected to an external AC power supply to work normally. When the external ambient temperature is not lower than 5°C, the temperature sensor of the temperature detection unit 10 corresponding to the first temperature switch T1 detects a temperature value greater than 5°C, and transmits the detected temperature value to the first temperature switch T1. The first temperature switch T1 is turned on, and the high temperature intermediate relay KA4 is energized and closed. Therefore, the normally open contact of the high temperature intermediate relay KA4 is electrically connected, the coil of the forward rotation contactor KM5 is electrically closed, and the normally open contact of the forward rotation contactor KM5 is turned on. As shown in Figure 3, the forward rotation drive circuit 20 works normally at this time, and because the normally closed contact of the reverse contactor KM4 of the reverse rotation drive circuit 30 is connected in series on the working circuit of its forward rotation contactor KM5, therefore, in the forward rotation The reverse interlock is realized when the drive circuit 20 is in the working state. At this time, the fan motor 50 is driven by the forward rotation drive circuit 20 to rotate in the forward direction, and the fan 60 performs the function of rotating and blowing air.

When the ambient temperature is lower than 5°C, the temperature sensor of the temperature detection unit 10 corresponding to the first temperature switch T1 detects a temperature value lower than 5°C, and the first temperature switch T1 is not turned on. The low-temperature intermediate relay KA5 is energized and closed, and its normally open contact is turned on. Then the reversing contactor KM4 is powered on, and its normally open contact is turned on. The reverse drive circuit 30 is in the working state, the fan motor 50 rotates in the reverse direction, and the fan 60 exhibits rotation and air suction.

When the ambient temperature is not lower than 35°C, the temperature sensor of the temperature detection unit 10 corresponding to the second temperature switch T2 detects a temperature value greater than 35°C, the second temperature switch T2 is turned on, and the high-temperature intermediate relay KA3 is energized and closed , its normally open contact is turned on, so the forward rotation contactor KM5 is closed and turned on, and the forward rotation drive circuit 20 is in the working state, so that the fan motor 50 rotates forward. Shown as fan 60 rotating to blow air.

When the high-temperature intermediate relay KA4 is turned on, the time relay KT2 is also turned on, and the time relay KT2 on the high-temperature intermediate relay KA3 branch is turned on, so that the high-temperature intermediate relay KA3 is also turned on. The time relay KT2 has a delay function, and its delay time can be 10 minutes. When the ambient temperature begins to be higher than the first preset temperature, the time relay KT2 with a delay function on the high-temperature intermediate relay KA3 branch is turned on after the delay time, so that the high-temperature intermediate relay KA3 is turned on, and the high-temperature intermediate of the forward rotation drive circuit 20 The relay KA3 is closed, the forward rotation contactor KM5 is connected, and the forward rotation drive circuit 30 is connected to make the cooling fan blow and rotate. The high-temperature intermediate relay KA3 of the forward rotation drive circuit 20 has a delay function, and a delay time, such as 5 seconds, can be set for the high-temperature intermediate relay KA3 as required. When the ambient temperature starts to be higher than the second preset temperature, the closing of the second temperature switch T2 ensures that the high-temperature intermediate relay KA3 is closed, ensuring that the cooling fan blows and rotates. When the ambient temperature begins to be lower than the first preset temperature, both the first temperature switch T1 and the second temperature switch T2 are in an open state, so that the high temperature intermediate relays KA3 and KA4 are in a power-off state, the low temperature intermediate relay KA5 is turned on, and the reverse Turning to the contactor KM4, the low-temperature intermediate relay KA5 of the reverse drive circuit 30 has a delay function, and the low-temperature intermediate relay KA5 can set a delay time as required, such as 5 seconds. The time relay KT2 is used to delay and change the rotation direction of the fan motor when the ambient temperature exceeds the first predetermined value. The delay point of the high-temperature intermediate relay KA3 and the low-temperature intermediate relay KA5 ensures that the motor can be powered off for a short time before the rotation direction changes, so that the fan motor rotates in the opposite direction after stopping, avoiding the change of the fan motor’s direction of rotation. Mechanical and electrical shock.

It can be seen from the above working process that the forward rotation drive circuit 20 and the reverse rotation drive circuit 30 can be in the working state respectively according to the ambient temperature detected by the temperature detection unit 10, that is, to drive the fan motor 50 to rotate forward or reversely, and Due to the circuit design of forward interlock and reverse interlock, the forward drive circuit 20 and the reverse drive circuit 30 will not be in working state at the same time.

In addition, when it can be determined that the ambient temperature is always greater than the above-mentioned first predetermined value, such as when the ambient temperature is always greater than 5°C, the switch QF6 of the bypass drive circuit 40 can be turned on, so that the forward rotation drive circuit 20 can work without passing through the temperature. control unit 10.

In fact, the first temperature switch T1 is used as a main control switch for the rotation direction of the fan motor 50 , and the second temperature switch T2 is used as an auxiliary control switch for the rotation direction of the fan motor 50 . When the ambient temperature is not lower than the second predetermined value, the second temperature switch T2 is turned on, so that the forward rotation contactor KM5 is turned on and turned on, so that the fan motor 50 rotates forward. And when the temperature is lower than the second predetermined value, the rotation direction of the fan motor 50 is controlled by the first temperature switch T1.

The utility model may have other modified implementation modes, such as, in fact, both the bypass drive circuit and the second temperature switch can be omitted, so that the cost of the switch control circuit can be saved more. In addition, in another modified embodiment, the time relay is not an essential element.

The above content is a further detailed description of the utility model in combination with specific preferred embodiments, and it cannot be assumed that the specific implementation of the utility model is only limited to these descriptions. For a person of ordinary skill in the technical field to which the utility model belongs, without departing from the concept of the utility model, some simple deduction or substitutions can also be made, which should be regarded as belonging to the protection scope of the utility model.

Claims (6)

1. fan control system is characterized in that: comprise the temperature detecting unit that is used for the testing environment temperature, be connected with temperature detecting unit respectively and carry out work and not in running order simultaneously drive circuit and the reversing drive circuit of just changeing according to the ambient temperature that temperature detecting unit detected.

2. fan control system as claimed in claim 1 is characterized in that: this temperature detecting unit comprises at least one ambient temperature value conducting that detection obtains according to temperature transducer or the thermal switch of closing and is used for the temperature transducer of testing environment temperature.

3. fan control system as claimed in claim 1 is characterized in that: further comprise fan electromotor, described fan electromotor is connected with described reversing drive circuit with the described drive circuit that just changeing respectively.

4. fan control system is characterized in that: comprise the temperature detecting unit that is used for the testing environment temperature, be connected with temperature detecting unit respectively and carry out work and not in running order simultaneously drive circuit and reversing drive circuit, high temperature auxiliary reclay, low temperature auxiliary reclay, positive contactor, counter-rotating contactor, first thermal switch and second thermal switch of just changeing according to the ambient temperature that temperature detecting unit detected.

5. fan control system as claimed in claim 4 is characterized in that: further comprise fan electromotor, described fan electromotor is connected with described reversing drive circuit with the described drive circuit that just changeing respectively.

6. fan control system as claimed in claim 5 is characterized in that: further comprise near the immovable time relay of sense of rotation that is used for keeping fan electromotor first predetermined value when ambient temperature changes in delay time with predefined delay time.

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