Driving circuit of electrically operated damper and AC ventilator

Abstract

A driving circuit of an electrically operated air door and an AC ventilator, comprising an electric mechanism and a control circuit thereof, the control circuit comprising: a power supply circuit, an electric energy source of an output end of which is from an AC power grid; an electric energy storage circuit, an electric energy source of an electric energy storage device is from the output end of the power supply circuit; an MCU circuit; an electric mechanism driving circuit, a control end of which is connected to an IO port of the MCU, an output end of which is connected to the electric mechanism, and an electric energy source of the electric energy storage device is connected to a power supply end thereof; an energy storage control circuit, a control end of which is connected to an IO port of the MCU, and a switch controlled thereby is connected across the output end of the power supply circuit and the power supply end of the MCU and the electric mechanism driving circuit; and a built-in program of the MCU controls the IO port: when the air door needs to be driven, the energy storage control circuit disconnects the output end of the power supply circuit from the power supply end of the MCU circuit and the electric mechanism driving circuit, and the electric mechanism operates; when the air door does not need to be driven, the output end of the power supply circuit is continuously or intermittently connected to the power supply end of the MCU circuit and the electric mechanism driving circuit, and the electric mechanism stops. The design makes the air door not need to be supplied with power from the AC power grid when it needs to be driven, thereby effectively avoiding the air door from being uncontrollable when the AC power grid is powered off.

Description

Technical Field

[0001] This invention relates to a drive circuit for an electric damper, and more particularly to an AC ventilator using the drive circuit, which may be classified under IPC categories E06B 9 / 00 and F04D 25 / 14. Background Technology

[0002] Traditional electric dampers are driven by an electric mechanism controlled by a drive circuit powered by AC mains. When the AC mains power is cut off, they are in an uncontrolled state, inevitably leading to many practical problems. These problems typically occur in AC ventilators that use this traditional electric damper.

[0003] For terms and general knowledge, unless otherwise specified in this manual, please refer to the national standard GB / T 14806—2017, the "Electrical Engineering Handbook", and the "Mechanical Engineering Handbook" (1st edition in 1978 and 2nd edition in 1997, published by Machinery Industry Press). Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a drive circuit for an electric damper and an AC ventilator using the drive circuit, which can improve the problems described in the background art compared with the traditional design.

[0005] The technical solution of this invention to solve the technical problem described in the background art is: a drive circuit for an electric damper, comprising an electric mechanism for driving the damper and a control circuit for the electric mechanism; characterized in that the control circuit comprises:

[0006] The power supply circuit has an output terminal (+5V) where the electrical energy comes from the AC power grid.

[0007] An energy storage circuit, including an energy storage device whose electrical energy originates from the output terminal (+5V) of the power supply circuit;

[0008] MCU circuit, including MCU, wherein the energy storage device is connected to the power supply terminal (VDD) of MCU.

[0009] The electric mechanism drive circuit has its control terminal connected to the IO port of the MCU, its output connected to the electric mechanism, and the energy storage device connected to its power supply terminal (VDD).

[0010] The energy storage control circuit has its control terminal connected to the IO port of the MCU. The switch controlled by this control terminal is connected across the output terminal (+5V) of the power supply circuit and the power supply terminal (VDD) of the MCU and the motor drive circuit.

[0011] The built-in program of the MCU controls the MCU's I / O ports:

[0012] a) When the damper requires an electric mechanism to operate:

[0013] —The energy storage control circuit, based on the IO port signal of the MCU connected to its control terminal, causes the switch to disconnect the output terminal (+5V) of the power supply circuit from the power supply terminal (VDD) of the MCU circuit and the electric mechanism drive circuit.

[0014] —The electric mechanism drive circuit is based on the IO port signal of the MCU connected to its control terminal, and its output causes the electric mechanism to move.

[0015] b) When the damper does not require an electric mechanism to operate:

[0016] —The energy storage control circuit, based on the IO port signal of the MCU connected to its control terminal, causes the switch to continuously or intermittently connect the output terminal (+5V) of the power supply circuit to the power supply terminal (VDD) of the MCU circuit and the electric mechanism drive circuit.

[0017] —The output of the electric mechanism drive circuit is based on the IO port signal connected to its control terminal, which causes the electric mechanism to stop.

[0018] This drive circuit cleverly utilizes the characteristic that the damper only needs to be driven for a short time. When the damper is not driven, it stores electrical energy from the AC power grid. When the damper needs to be driven, the stored electrical energy is used to activate the electric mechanism to drive the damper. At this time, the power input of the electric mechanism is separated from the AC power grid, so that the damper does not need AC power supply in any situation where it needs to be driven, thereby effectively preventing it from being out of control when the AC power grid is cut off.

[0019] The electric mechanism typically uses a stepper motor. Under the control of the built-in program in the MCU circuit, the stepper motor can accurately drive the damper to the specified opening degree, rather than simply actuating the damper to two open states, such as fully open or fully closed, like a wax motor or electromagnet.

[0020] The technical solution of the AC ventilator using the above-mentioned drive circuit of the present invention is that the AC ventilator includes an AC motor that drives the ventilator impeller to rotate. The AC motor is connected to the output terminal (+5V) of the power supply circuit of the control circuit, and the power supply circuit output terminal (+5V) is connected to the IO port of the MCU circuit.

[0021] When the AC fan is in normal use, the damper should be open when the AC motor is powered on and closed when the power is off. When the AC mains connected to the AC motor are powered on, the +5V output of the power supply circuit receives power from the AC mains, effectively sending a signal that the damper needs to be opened. This signal is received by the MCU circuit's I / O port, and the built-in program causes the stepper motor drive circuit to output a clockwise rotation signal to the stepper motor, which then drives the damper to open. When the AC mains connected to the AC motor are de-energized, the +5V output of the power supply circuit simultaneously loses power, effectively sending a signal that the damper needs to be closed. This signal is received by the MCU circuit's I / O port, and the built-in program causes the stepper motor drive circuit to output a counter-clockwise rotation signal to the stepper motor, which then drives the damper to close.

[0022] This specific connection enables the ventilator to automatically open the damper when the AC motor is connected to the specified AC power grid, and automatically close the damper when the specified AC power grid is disconnected, thereby effectively preventing the AC ventilator from shutting down uncontrollably when the AC power grid is cut off, and the control structure is very simple. Attached Figure Description

[0023] Figure 1 This is a front view schematic diagram of the ventilation fan structure according to an embodiment of the present invention.

[0024] Figure 2 This is a schematic diagram of the ventilation fan circuit according to an embodiment of the present invention.

[0025] Figure 3 This is a flowchart of the MCU initialization process in the built-in program of the ventilator circuit MCU in an embodiment of the present invention.

[0026] Figure 4 This is a flowchart of the ventilation fan circuit MCU built-in program's control process for opening the damper when the ventilation fan is powered on, according to an embodiment of the present invention.

[0027] Figure 5 This is a flowchart of the ventilator circuit MCU built-in program's energization, energy storage, and charging control process according to an embodiment of the present invention.

[0028] Figure 6 This is a flowchart of the ventilation fan circuit MCU built-in program's control process for the ventilation fan's damper closing when the power is off, according to an embodiment of the present invention. Detailed Implementation

[0029] Example 1

[0030] like Figures 1-6 The ventilator shown is an electrically operated shielded type as described in Chapter 4 of the national standard GB / T 14806—2017, and is an improvement on the applicant's prior design as described in CN207554389U.

[0031] The basic structure of inheriting prior design, such as Figure 1 As shown, it mainly includes:

[0032] —Window frame 4 serving as the machine base;

[0033] —An AC motor 2 fixed to the window frame 4;

[0034] —Axial flow impeller 1 fixed on the shaft of AC motor 2;

[0035] —Feng Kou 5;

[0036] — Baffle 3, i.e., the damper, is a flat plate that faces the air vent 5 perpendicularly to the airflow axis.

[0037] —The slide bar 6 is fastened to the baffle 3, and its direction of movement is parallel to the airflow axis of the air outlet 5;

[0038] —The guide rail 7 is integrated with the window frame 4 and moves axially around the slide rod 6 so that it can only move left and right;

[0039] —Lever 8, when it rotates clockwise, its upper arm rotates to the right to press against slide bar 6, pushing slide bar 6 to move to the right;

[0040] —A cylindrical compression spring 10 is located inside the cavity of the slide rod 6. One end of the spring is fixed to a positioning post that is integrated with the window frame 4, and the other end abuts against the left end of the cavity of the slide rod 6.

[0041] The main design modifications are:

[0042] 1. In CN207554389U, the electric mechanism of the driving lever 8 is changed from a wax motor to a stepper motor and its transmission mechanism. Specifically, the end of the drive rod 91 of the stepper motor and its transmission mechanism 9 abuts against the lower arm of the lever 8. The transmission mechanism of the stepper motor can convert the rotation of the stepper motor into the up-and-down linear motion of the drive rod 91 via a gear rack or screw nut transmission.

[0043] —When rotated clockwise, the drive rod 91 extends upward and presses against the lever 8, causing the lever 8 to rotate clockwise. Its upper arm presses against the slide rod 6 to the right, pushing the slide rod 6 to move to the right. At the same time, it compresses the compression spring 10 and pushes the baffle 3 to the right, opening the air vent 5.

[0044] —When rotated counterclockwise, the drive rod 91 retracts downward, the compression spring 10 returns to its original position and extends, pushing the slide rod 6 to move to the left, pulling the baffle 3 back to the left, and closing the air vent 5.

[0045] 2. The circuit for supplying power to the 9th winding of the stepper motor is shown below. Figure 2 The control circuit shown includes:

[0046] a) Power supply circuit

[0047] When the AC motor 2 is directly connected to the ventilation fan, the 220V / 50Hz AC voltage on the AC power terminals L and N of L and N is transformed by overvoltage protection, half-wave rectification, filtering and switching power supply chip and its output circuit to provide +5V DC voltage to each circuit at the +5V output terminal and common ground GND.

[0048] b) The energy storage circuit consists of supercapacitors EC1 and EC4 connected in parallel with resistors R1 and R2, and then connected in series across the power supply terminal VDD and the common ground GND.

[0049] c) MCU circuit: Pin 8 of the MCU chip is connected to the common ground GND; Pin 1 is the power supply terminal and is connected to the power supply terminal VDD; Pin 3 (IO port) is connected to the output terminal +5V of the power supply circuit through diode D3 and resistor R17.

[0050] d) Electric mechanism drive circuit: pin 5 of the dedicated stepper motor drive chip U2 is connected to the common ground GND, and pin 6 is the power supply terminal, connected to the power supply terminal VDD; pins 1, 2, 3, and 4 of the chip are the control terminals of the circuit, connected to the IO ports of pins 4, 5, 6, and 7 of the MCU; the output of the chip is connected to the winding input terminal of the stepper motor via pins 7-10 and terminal CN1.

[0051] e) Energy storage control circuit: transistor Q3 is coupled to Q1 to control the gate of switch Q2. The base pin 1 of Q3 is used as the control terminal of the circuit and connected to pin 2 of the MCU. The main electrode of switch Q2 controlled by this control terminal is used as an electronic switch. After connecting the isolation diode D6 and the current limiting resistor in series, it is connected across the output terminal +5V of the power supply circuit and the power supply terminal VDD of the MCU circuit and the electric mechanism drive circuit.

[0052] MCU has such Figure 3 —6 shows the control of its various I / O ports, and thus through Figure 2 The built-in program shown connects and controls each circuit to meet the following requirements:

[0053] a) When the damper 3 of the ventilator requires the stepper motor and its transmission mechanism 9 to operate for driving:

[0054] —Based on the signal from pin 2 of the MCU connected to its control terminal, the energy storage control circuit causes the switching transistor Q2 to disconnect the +5V output terminal of the power supply circuit from the power supply terminal VDD of the MCU circuit and the electric mechanism drive circuit.

[0055] —The electric mechanism drive circuit outputs a corresponding voltage to the stepper motor windings based on the IO port signals of pins 4-7 of the MCU connected to its control terminal, so that the stepper motor can move. For example: when the fan is started, the AC power terminals L and N are energized and the AC motor 2 drives the impeller 1 to rotate clockwise, opening the air vent 5 through the various transmission structures; when the fan is turned off, the AC power terminals L and N are de-energized and the AC motor 2 and the impeller 1 stop rotating and rotate counterclockwise, closing the air vent 5 through the transmission structure.

[0056] b) When the damper 3 of the ventilator stops without the stepper motor and its transmission mechanism 9 being driven by it:

[0057] —The energy storage control circuit uses the I / O port signal of pin 2 of the MCU to connect the output of the power supply circuit +5V to the power supply terminal VDD of the MCU circuit and the electric mechanism drive circuit, so as to supplement the power energy from the AC grid. After charging to the specified value, it disconnects.

[0058] —The output of the electric mechanism drive circuit is based on the IO port signals of pins 4-7 of the MCU connected to its control terminal. It stops outputting the corresponding voltage to the stepper motor winding, so that the stepper motor stops and the damper stops moving.

[0059] The pin numbers, markings, and functions of chip U2 are shown in the table below.

[0060] 1 1B 1-channel signal input pin 2 2B 2-channel signal input pins 3 3B 3-channel signal input pins 4 4B 4-channel signal input pins 5 E Ground - GND 6 COM Connect to power supply - VDD 7 4C 4-channel output pins 8 3C 3-channel output pins 9 2C 2-channel output pins 10 1C 1-channel output pin

[0061] The pin numbers, markings, and functions of chip U3 are shown in the table below.

[0062] 1 VDD Connect to power supply - VDD 2 TOCKI / PORTB2 I / O input / output ports 3 VPP / PORTB5 I / O input / output ports 4 T2CKI / PORTA7 I / O input / output ports 5 PORTA2 / PCK I / O input / output ports 6 PORTA1 / PGD I / O input / output ports 7 PORTA0 / PGC I / O input / output ports 8 GND Ground - GND

[0063] Example 2

[0064] The ventilation fan in this embodiment is an improvement on another prior design of the applicant described in CN101285486A, and also belongs to the electrically operated shielding type described in Chapter 4 of GB / T14806—2017. Compared with the first embodiment, the main difference is that the micro motor used in the micro motor driver for driving the window blades described in CN101285486A is a stepper motor. The rest are the same as the first embodiment based on CN207554389U except for the mechanical structure, and will not be described again.

[0065] 3rd Embodiment

[0066] This embodiment is an electric damper, and its circuit is compared to... Figure 2 The main differences are:

[0067] —Remove AC motor 2;

[0068] —Pin 3 (IO port) of the MCU circuit is connected to the +5V output of the power supply circuit via diode D3 and resistor R17. This is then used to connect to the electrical output of a sensor that automatically responds to the operation of the stepper motor required to drive the damper. For example, a photosensitive battery can be used as this sensor to control the damper of a plant cultivation box.

[0069] In addition to controlling the opening and closing positions of the air damper as in embodiments 1 and 2, the electric damper in this embodiment can also be adjusted to move the damper to a specified opening degree by adjusting the built-in program.

[0070] In this embodiment, the stepper motor can be replaced with a reversible AC capacitor motor to reduce costs, but this reduces the accuracy of the damper's opening and closing positioning.

Claims

1. A drive circuit for an electric damper, comprising an electric mechanism for driving the damper and a control circuit for the electric mechanism; characterized in that, The control circuit includes: The power supply circuit has an output terminal (+5V) where the electrical energy comes from the AC power grid. An energy storage circuit, including an energy storage device whose electrical energy originates from the output terminal (+5V) of the power supply circuit; MCU circuit, including MCU, wherein the energy storage device is connected to the power supply terminal (VDD) of MCU. The electric mechanism drive circuit has its control terminal connected to the IO port of the MCU, its output connected to the electric mechanism, and the energy storage device connected to its power supply terminal (VDD). The energy storage control circuit has its control terminal connected to the IO port of the MCU. The switch controlled by this control terminal is connected across the output terminal (+5V) of the power supply circuit and the power supply terminal (VDD) of the MCU and the motor drive circuit. The built-in program of the MCU controls the MCU's I / O ports: a) When the damper requires an electric mechanism to operate: —The energy storage control circuit, based on the IO port signal of the MCU connected to its control terminal, causes the switch to disconnect the output terminal (+5V) of the power supply circuit from the power supply terminal (VDD) of the MCU circuit and the electric mechanism drive circuit. —The electric mechanism drive circuit is based on the IO port signal of the MCU connected to its control terminal, and its output causes the electric mechanism to move. b) When the damper does not require an electric mechanism to operate: —The energy storage control circuit, based on the IO port signal of the MCU connected to its control terminal, causes the switch to continuously or intermittently connect the output terminal (+5V) of the power supply circuit to the power supply terminal (VDD) of the MCU circuit and the electric mechanism drive circuit. —The output of the electric mechanism drive circuit is based on the IO port signal connected to its control terminal, which causes the electric mechanism to stop.

2. The driving circuit according to claim 1, characterized in that: The electric mechanism is a stepper motor or a stepper motor and its transmission mechanism.

3. An AC ventilator, comprising an AC motor for driving the ventilator impeller, characterized in that, It has the drive circuit as described in claim 1 or claim 2; the AC motor is connected to the output terminal (+5V) of the power supply circuit of the control circuit, and the power supply circuit output terminal (+5V) is connected to the IO port of the MCU circuit.

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