阅读说明：本技术 一种风扇触摸刹车电路 (Fan touch brake circuit ) 是由 周远锋 于 2021-06-17 设计创作，主要内容包括：本发明公开了一种风扇触摸刹车电路,包括触摸感应电路、继电器控制电路、电源电路和主MCU。本发明中人体阻抗、C3、R7、R8、Q1、电路板GND和大地构成闭合回路,Q1将以50Hz或60Hz的频率进行开闭,Q1的集电极产生50Hz的方波信号,当电路板的MCU检测到此方波信号,MCU的PA0口将输出高电平,控制继电器K2断开风机正常工作时的交流电压,同时MCU的PA4口将输出高电平,控制继电器K1接通风机刹车时所需要的直流电压,当正常运转的交流异步电机绕组突然接入直流电压后,转子会急速刹车停转,从而实现人体触摸落地扇金属外壳后,电机能够急速刹车,有效起到抑制电火弧的产生,保护继电器K1不被烧毁。(The invention discloses a fan touch brake circuit which comprises a touch sensing circuit, a relay control circuit, a power circuit and a main MCU. The human body impedance, C3, R7, R8, Q1, a circuit board GND and the ground form a closed loop, Q1 is switched at the frequency of 50Hz or 60Hz, a collector of Q1 generates a 50Hz square wave signal, when an MCU of the circuit board detects the square wave signal, a PA0 port of the MCU outputs high level, a control relay K2 cuts off alternating current voltage when a fan normally works, meanwhile, the PA4 port of the MCU outputs high level, the control relay K1 switches on direct current voltage required when the fan brakes, and after an alternating current asynchronous motor winding which normally works is suddenly switched on the direct current voltage, a rotor can rapidly brake and stop rotating, so that after a human body touches a metal shell of a floor fan, the motor can rapidly brake, the generation of electric spark arcs is effectively inhibited, and the relay K1 is protected from being burnt.)

1. The utility model provides a fan touch brake circuit, includes touch-sensitive circuit, relay control circuit, power supply circuit and main MCU, its characterized in that: one end of the touch sensing circuit is connected with a metal outer casing of the floor fan, the main MCU respectively controls the touch sensing circuit and the relay control circuit in an electric signal mode, and the power supply circuit provides power supply voltage for the relay control circuit and the main MCU;

the touch sensing circuit comprises a capacitor C3, a resistor R7, a resistor R8, a resistor R11, a triode Q1, a resistor R3 and a capacitor C4, one end of the capacitor C3 is connected with the metal outer casing of the floor fan, the other end of the capacitor C3 is connected with a resistor R7, one end of the resistor R7 is connected with the resistor R8, one end of the resistor R8 is respectively connected with the resistor R11 and the triode Q1, one end of the triode Q1 is connected with the resistor R11, the other end of the triode Q1 is connected with the resistor R3, and one end of the resistor R3 is connected with the capacitor C4;

the relay control circuit comprises a first relay control circuit and a second relay control circuit, wherein the first relay control circuit comprises a relay K1, a diode D3, a triode Q3, a resistor R13, a capacitor C2, a resistor R5, a resistor R4, a resistor R6, a resistor R9, a controller EC1 and a diode D1, a pin 3 of the relay K1 is connected with a LOUT line, a pin 1 and a pin 2 of the relay K1 are both connected with the diode D1, one end of the diode D1 is connected with the triode Q1, one end of the triode Q1 is connected with the resistor R1, a pin 4 and a pin 5 of the relay K1 are both connected with the capacitor C1, one end of the capacitor C1 is connected with the resistor R1, one end of the resistor R1 is connected with the resistor R1, the resistor R1 and the resistor R1, the other end of the resistor R1 is connected with the controller EC1, one end of the diode EC1 is connected with the diode D1, the second relay control circuit comprises a relay K2, a diode D2, a triode Q2 and a resistor R12, wherein a pin 1 of the relay K2 is connected with a triode Q2, a pin 2 of the relay K2 is connected with a diode D2, one end of the triode Q2 is connected with a resistor R12, and a pin 4 of the relay K1 is connected with a LOUT line.

2. The fan touch brake circuit of claim 1, wherein: and the relay K2 is used for controlling the on-off of the alternating voltage when the motor works normally.

3. The fan touch brake circuit of claim 1, wherein: and the relay K1 is used for controlling the on-off of the direct-current voltage when the motor brakes.

4. The fan touch brake circuit of claim 1, wherein: the power supply circuit converts commercial power with the voltage of 110 VAC-240 VAC and the frequency of 50Hz or 60Hz into 12VDC through non-isolated DCDC, the 12VDC is used for the power supply voltage of the relay, and the 12VDC is converted into 5VDC through the linear voltage reduction chip and is used for the power supply voltage of the main MCU.

5. The fan touch brake circuit of claim 1, wherein: the main MCU is used for detecting a touch input signal and outputting control signals of two relays K1 and K2.

6. The fan touch brake circuit of claim 1, wherein: the touch sensing circuit is used for detecting whether a human body touches the metal outer casing of the floor fan.

Technical Field

The invention relates to the technical field of fans, in particular to a fan touch brake circuit.

Background

At present, motors in common fans on the market can not brake rapidly, although some alternating current asynchronous motors brake rapidly by connecting direct current voltage, when braking is completed, connection between a direct current power supply and a motor winding needs to be disconnected, at the moment, due to the characteristics of inductance of the motor winding, electric arcs are generated at pins 4 and 5 of a relay K1 during power failure, if proper circuit processing is not available, the electric arcs can exist continuously, devices in the circuit are damaged, and great inconvenience is brought to users.

Disclosure of Invention

The invention aims to provide a fan touch brake circuit to solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: a fan touch brake circuit comprises a touch sensing circuit, a relay control circuit, a power supply circuit and a main MCU, wherein one end of the touch sensing circuit is connected with a metal outer casing of a floor fan, the main MCU respectively controls the touch sensing circuit and the relay control circuit in an electric signal mode, and the power supply circuit provides power supply voltage for the relay control circuit and the main MCU;

the touch sensing circuit comprises a capacitor C3, a resistor R7, a resistor R8, a resistor R11, a triode Q1, a resistor R3 and a capacitor C4, one end of the capacitor C3 is connected with the metal outer casing of the floor fan, the other end of the capacitor C3 is connected with a resistor R7, one end of the resistor R7 is connected with the resistor R8, one end of the resistor R8 is respectively connected with the resistor R11 and the triode Q1, one end of the triode Q1 is connected with the resistor R11, the other end of the triode Q1 is connected with the resistor R3, and one end of the resistor R3 is connected with the capacitor C4;

the relay control circuit comprises a first relay control circuit and a second relay control circuit, wherein the first relay control circuit comprises a relay K1, a diode D3, a triode Q3, a resistor R13, a capacitor C2, a resistor R5, a resistor R4, a resistor R6, a resistor R9, a controller EC1 and a diode D1, a pin 3 of the relay K1 is connected with a LOUT line, a pin 1 and a pin 2 of the relay K1 are both connected with the diode D1, one end of the diode D1 is connected with the triode Q1, one end of the triode Q1 is connected with the resistor R1, a pin 4 and a pin 5 of the relay K1 are both connected with the capacitor C1, one end of the capacitor C1 is connected with the resistor R1, one end of the resistor R1 is connected with the resistor R1, the resistor R1 and the resistor R1, the other end of the resistor R1 is connected with the controller EC1, one end of the diode EC1 is connected with the diode D1, the second relay control circuit comprises a relay K2, a diode D2, a triode Q2 and a resistor R12, wherein a pin 1 of the relay K2 is connected with a triode Q2, a pin 2 of the relay K2 is connected with a diode D2, one end of the triode Q2 is connected with a resistor R12, and a pin 4 of the relay K1 is connected with a LOUT line.

Preferably, the relay K2 is used for controlling the on-off of the alternating voltage when the motor works normally.

Preferably, the relay K1 is used for controlling the on-off of the direct current voltage when the motor brakes.

Preferably, the power supply circuit converts commercial power with the voltage of 110 VAC-240 VAC and the frequency of 50Hz or 60Hz into 12VDC through non-isolated DCDC, the 12VDC is used for the power supply voltage of the relay, and the 12VDC is converted into 5VDC through the linear voltage reduction chip and is used for the power supply voltage of the main MCU.

Preferably, the main MCU is used for detecting a touch input signal and outputting control signals of the two relays K1 and K2.

Preferably, the touch sensing circuit is used for detecting whether a human body touches the metal outer casing of the floor fan.

Compared with the prior art, the invention has the following beneficial effects:

the human body impedance, C3, R7, R8, Q1, a circuit board GND and the ground form a closed loop, Q1 is switched at the frequency of 50Hz or 60Hz, a collector of Q1 generates a 50Hz square wave signal, when an MCU of the circuit board detects the square wave signal, a PA0 port of the MCU outputs high level, a control relay K2 cuts off alternating current voltage when a fan normally works, meanwhile, the PA4 port of the MCU outputs high level, the control relay K1 switches on direct current voltage required when the fan brakes, and after an alternating current asynchronous motor winding which normally works is suddenly switched on the direct current voltage, a rotor can rapidly brake and stop rotating, so that after a human body touches a metal shell of a floor fan, the motor can rapidly brake, the generation of electric spark arcs is effectively inhibited, and the relay K1 is protected from being burnt.

Drawings

FIG. 1 is a diagram of a touch sensing circuit according to the present invention;

fig. 2 is a circuit diagram of a relay control circuit according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-2, a touch brake circuit for a fan includes a touch sensing circuit, a relay control circuit, a power circuit and a main MCU, wherein one end of the touch sensing circuit is connected to a metal casing of a floor fan, the main MCU controls the touch sensing circuit and the relay control circuit respectively by means of electrical signals, and the power circuit provides power voltage for the relay control circuit and the main MCU.

The touch sensing circuit comprises a capacitor C3, a resistor R7, a resistor R8, a resistor R11, a triode Q1, a resistor R3 and a capacitor C4, one end of the capacitor C3 is connected with the metal outer casing of the floor fan, the other end of the capacitor C3 is connected with a resistor R7, one end of the resistor R7 is connected with the resistor R8, one end of the resistor R8 is connected with the resistor R11 and the transistor Q1 respectively, one end of the transistor Q1 is connected with the resistor R11, the other end of the transistor Q1 is connected with the resistor R3, and one end of the resistor R3 is connected with the capacitor C4.

Relay control circuit the first relay control circuit comprises a relay K1, a diode D1, a transistor Q1, a resistor R1, a capacitor C1, a resistor R1, a controller EC1, a diode D1, pin 3 of the relay K1 is connected with a LOUT line, pin 1 and pin 2 of the relay K1 are both connected with the diode D1, one end of the diode D1 is connected with the transistor Q1, one end of the transistor Q1 is connected with the resistor R1, pin 4 and pin 5 of the relay K1 are both connected with the capacitor C1, one end of the capacitor C1 is connected with the resistor R1, one end of the resistor R1 is connected with the resistor R1, the other end of the resistor R1 is connected with the controller EC1, one end of the controller EC1 is connected with the diode D1, the second relay control circuit comprises the relay K1, the diode Q1, the transistor R1, the transistor D1, and the diode D1, The resistor R12 and the pin 1 of the relay K2 are connected with the triode Q2, the pin 2 of the relay K2 is connected with the diode D2, one end of the triode Q2 is connected with the resistor R12, and the pin 4 of the relay K1 is connected with a LOUT line.

In specific implementation, the relay K2 is used for controlling the on-off of the alternating voltage when the motor works normally.

In the specific implementation, the relay K1 is used for controlling the on-off of the direct-current voltage when the motor brakes.

In the specific implementation, the mains supply with the voltage of 110 VAC-240 VAC and the frequency of 50Hz or 60Hz is converted into 12VDC by the power supply circuit through non-isolated DCDC, the 12VDC is used for the power supply voltage of the relay, and the 12VDC is converted into 5VDC by the linear voltage reduction chip and used for the power supply voltage of the main MCU.

In specific implementation, the main MCU is used for detecting a touch input signal and outputting control signals of the two relays K1 and K2.

In specific implementation, the touch sensing circuit is used for detecting whether a human body touches the metal outer casing of the floor fan.

When the grounding fan is used, the metal outer casing of the grounding fan is connected with one end of a C3 capacitor in a circuit diagram, a human body is equivalent to a fixed impedance, when the human body touches the metal outer casing of the grounding fan, the human body impedance, C3, R7, R8, Q1, a circuit board GND and the ground form a closed loop, Q1 is opened and closed at the frequency of 50Hz or 60Hz, a collector of Q1 generates a square wave signal of 50Hz, when the MCU of the circuit board detects the square wave signal, a PA0 port of the MCU outputs a high level, a relay K2 is controlled to cut off the alternating current voltage when the fan normally works, meanwhile, a PA4 port of the MCU outputs the high level, the relay K1 is controlled to switch on the direct current voltage required when the fan brakes, and stops the rotor rapidly after the alternating current asynchronous motor winding which normally works is suddenly switched on the direct current voltage, and therefore, after the human body touches the metal outer casing of the grounding fan, the motor can rapidly brake; the rapid braking of the alternating current asynchronous motor is realized by accessing direct current voltage, after the braking is finished, the connection between a direct current power supply and a motor winding needs to be disconnected, at the moment, due to the characteristic of the inductance of the motor winding, electric arcs are generated at pins 4 and 5 of a relay K1 during power failure, if proper circuit processing is not available, the electric arcs can continuously exist, so that devices in a circuit are damaged, the generation of the electric arcs is effectively restrained by connecting C2 (a film capacitor made of a CBB1/CBB2 material) at the pin 4 and the pin 5 of the relay K1 in parallel, and the relay K1 is protected from being burnt.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.