CN206503752U - A kind of air-conditioning draught fan - Google Patents

Abstract

The utility model discloses a kind of air-conditioning draught fan, its drip irrigation device is to include spiral case, impeller and motor with air inlet and air outlet；Open stopping detecting circuit be used for detect input start stop signal be located at rising edge or trailing edge when, output accordingly detect signal；Counting circuit input is coupled to the output end for opening stopping detecting circuit, and is counted in response to detection signal and export corresponding count signal from its output end after the full pre-determined number of meter；Time-delay reset circuit triggering end is coupled to the output end of counting circuit, and enters line delay in response to count signal, and corresponding delayed reset signal is exported after preset time to the reset terminal of counting circuit；On-off circuit input is coupled to counting circuit with count pick up signal, and exports corresponding switching signal from its output end；The normally-closed contact of relay one is serially connected on the start-up circuit of motor, and its coil is coupled to the output end of on-off circuit to receive switching signal, and controls in response to switching signal the break-make of its normally-closed contact.

Description

A kind of air-conditioning draught fan

Technical field

The utility model is related to Fan Equipment field, more particularly to a kind of air-conditioning draught fan.

Background technology

Air-conditioning draught fan is mostly mounted in occasions such as hotel, Office Area, civilian ventilations.

Existing air-conditioning draught fan include spiral case, air inlet and air outlet on spiral case, be provided with spiral case impeller, And for driving the motor of the wheel rotation.Wherein, start-up circuit is connected with motor, being connected with the start-up circuit is used for Start the starting switch of motor and the closing switch for closing motor.

When needing to use the air-conditioning draught fan, it is only necessary to press starting switch and turn on the current supply circuit of motor, motor drives Movable vane wheel high-speed rotation, wind is sucked from air inlet and blown out at air outlet；If but operating personnel's misoperation causes the electricity Machine frequent starting, electric current during due to electric motor starting is larger, and burn-down of electric motor is easily caused in frequent starting, influences the air-conditioning draught fan Normally use.

Utility model content

In view of the deficienciess of the prior art, the purpose of this utility model is to provide a kind of air-conditioning draught fan, with avoiding The characteristics of motor frequent starting.

Above-mentioned technical purpose of the present utility model technical scheme is that：

A kind of air-conditioning draught fan, including the spiral case with air inlet and air outlet, the impeller in spiral case and for driving Move and guard assembly is connected with the motor of the wheel rotation, the motor, the guard assembly includes housing and located at housing The starting switch and closing switch for motor start and stop are connected with the start-up circuit of interior motor, the start-up circuit, it is described to open Start stop signal input circuit is coupled with dynamic circuit, is coupled with the start stop signal input circuit for preventing motor frequent starting Start and stop protection circuit, the start and stop protection circuit includes：

Stopping detecting circuit is opened, it has input and output end, for detecting the start stop signal inputted in its input During positioned at rising edge or trailing edge, the corresponding detection signal of its output end output；

Counting circuit, it has input, output end and reset terminal, and the input of the counting circuit is coupled to start and stop inspection The output end of slowdown monitoring circuit, and counted in response to detection signal and export corresponding from its output end after the full pre-determined number of meter Count signal；

Time-delay reset circuit, it has triggering end and output end, and the triggering end of the time-delay reset circuit is coupled to counting electricity The output end on road, and enter line delay in response to count signal, corresponding delayed reset signal is exported after preset time to counting The reset terminal of circuit；

On-off circuit, it has input and output end, and its input is coupled to counting circuit with count pick up signal, and Corresponding switching signal is exported from its output end；

Relay one, its normally-closed contact is serially connected on the start-up circuit of motor, and its coil is coupled to the output of on-off circuit End controls in response to switching signal the break-make of its normally-closed contact to receive switching signal.

By above-mentioned technical proposal, press one-shot switch and will give and open stopping detecting circuit and input opening for rising edge Stop signal, counting circuit is accordingly counted once, given during by closing switch next time and open a stopping detecting circuit trailing edge of input Start stop signal, counting circuit is accordingly counted once, if being counted as the pre-determined number of counting circuit, now, on-off circuit twice Control relay one is acted so that the motor can not be activated switch and start in the given time, so as to a certain extent Eliminate the hidden danger that motor burns by frequent starting.

It is preferred that, the start stop signal input circuit includes：

Current transformer, it has input and output end, and its input is coupled on the start-up circuit of motor, and from its Output end exports corresponding mutual inductance current value；

Rectifier bridge, it has input and output end, and its input is coupled in the output end of current transformer；

Load resistance, it is coupled in the output end of rectifier bridge, to export corresponding start stop signal to opening stopping detecting circuit.

By above-mentioned technical proposal, the mutual inductance current value on motor start circuit is obtained using current transformer, to detect The mode of mutual inductance current value replaces the electric current on directly detection motor start circuit, accuracy of detection is not only increased, in certain journey Avoid opening the damage of stopping detecting circuit on degree.

It is preferred that, the stopping detecting circuit that opens includes two block registers, the first not circuit, first and gate circuit, second Not circuit, second and gate circuit and OR circuit；The input of first not circuit is coupled to rear stage register Output end；The input of second not circuit is coupled to the output end of previous stage register；Described first and gate circuit One of input be coupled to the output end of previous stage register, another input is coupled to the defeated of the first not circuit Go out end；Described second is coupled to the output end of the second not circuit, another input with one of output end of gate circuit It is coupled to the output end of rear stage register；Two inputs of the OR circuit are respectively coupled to first and gate circuit and the Two and gate circuit.

By above-mentioned technical proposal, register is to latch incoming level when start stop signal rising edge arrives, deposit Device latches the saltus step of next start stop signal（Trailing edge）Incoming level during arrival, if what the two registers latch were lived Level signal is different, and edge, i.e. rising edge or trailing edge are detected with regard to explanation.

It is preferred that, the counting circuit uses counter.

By above-mentioned technical proposal, counter cost is relatively low, it is easy to the maintenance and replacing in later stage.

It is preferred that, the time-delay reset circuit is integrated using 555 timing chips.

By above-mentioned technical proposal, 555 timing chip costs are relatively low, it is easy to the maintenance and replacing in later stage.

It is preferred that, the on-off circuit includes：

3rd resistor, its one end is coupled to the output end of counting circuit；

4th resistance, its one end is coupled to the other end of 3rd resistor, its other end ground connection；

Second triode, its base stage is coupled on the tie point between 3rd resistor and the 4th resistance, its grounded emitter, Its colelctor electrode connects voltage vcc after being coupled to the coil of relay one；

Diode, its two ends inverse parallel is at the coil two ends of relay one.

By above-mentioned technical proposal, the second triode is used as switching tube, the characteristics of with being quick on the draw；Diode is made Used for fly-wheel diode, with when relay one is powered off, the electric current in the coil of relay one can be discharged.

It is preferred that, the air-conditioning draught fan also includes the rectangular frame for supporting spiral case, the rectangle frame located at spiral case both sides The bearing being provided with cross bar and montant, the tie point between the cross bar and montant for fixing machine shaft is installed on frame Seat.

By above-mentioned technical proposal, cross bar and the T-shaped fixation of montant, the rotating shaft two ends of motor are respectively mounted and impeller and axle In bearing, to effectively improve stability when motor is rotated.

It is preferred that, the casing for being coated on scroll outer, the casing and spiral case are connected between the rectangular frame of both sides Between be filled with Sound-proof material.

By above-mentioned technical proposal, when motor driven impeller is rotated, wind enters from air outlet blowout from air inlet, passes through The Sound-proof material of scroll outer is coated on, the generation of noise can be effectively reduced.

It is preferred that, the guard assembly also includes：

Storage tank, it is on the outer wall of housing；

RF transmitter, it is located on the side cell wall of storage tank to send infrared light；

Infrared receiver, it is oppositely arranged red to receive on the opposite side cell wall of storage tank with RF transmitter Outer light simultaneously exports corresponding infrared detection signal；

Control device, it is coupled to infrared receiver and detects signal with receiving infrared-ray, and exports corresponding control letter Number；

Relay two, there is the first normally opened contact to be serially connected on start-up circuit for it, and its coil is coupled to control device to connect Control signal is received, and in response to control signal to control the break-make of its first normally opened contact.

By above-mentioned technical proposal, it is necessary to which operating personnel are manually placed in the storage tank before the air-conditioning draught fan is started The infrared light that sends of cut-off RF transmitter so that it is infrared that infrared receiver can not receive that RF transmitter sends Light, by the closure of the first normally opened contact of control device control relay two, to turn on the current supply circuit of start-up circuit, this When, starting switch is pressed so that the motor of air-conditioning draught fan can be activated, further to prevent the air-conditioning draught fan by frequent starting.

It is preferred that, the relay two also has the second normally opened contact, and the described second normally opened touch is connected in control dress in parallel Put and self-locking state is in control relay two.

Pass through above-mentioned technical proposal, the setting of the second normally opened contact, it is ensured that air-conditioning draught fan is on startup, it is to avoid operating personnel Continue to go cut-off infrared light further to improve the practicality of the circuit with hand.

In summary, the utility model having the beneficial effect that in contrast to prior art：

The start stop signal for opening a stopping detecting circuit rising edge of input, counting circuit phase will be given by pressing one-shot switch It should count once, be given during by closing switch next time and open the start stop signal that stopping detecting circuit inputs a trailing edge, count electricity Road is accordingly counted once, if being counted as the pre-determined number of counting circuit twice, and now, on-off circuit moves control relay one Make so that the motor can not be activated switch and start in the given time, so as to eliminate motor to a certain extent because frequently The hidden danger for starting and burning.

Brief description of the drawings

Fig. 1 is the structural representation of embodiment；

Fig. 2 is the side view of embodiment；

Fig. 3 is the system block diagram of embodiment；

Fig. 4 is the circuit diagram of start and stop protection circuit；

Fig. 5 is the circuit diagram for opening stopping detecting circuit；

Fig. 6 is the circuit diagram of counting circuit；

Fig. 7 is the circuit diagram of time-delay reset circuit；

Fig. 8 is the circuit diagram of on-off circuit；

Fig. 9 is the circuit diagram of RF transmitter, infrared receiver and control device.

Reference：1st, air inlet；2nd, air outlet；3rd, spiral case；4th, rectangular frame；5th, cross bar；6th, montant；7th, bearing block； 8th, impeller；9th, motor；10th, casing；101st, foreboard；102nd, back plate；103rd, top plate；104th, bottom plate；105th, side plate；11st, Sound-proof material； 100th, start-up circuit；200th, guard assembly；210th, housing；220th, storage tank；230th, RF transmitter；240th, infrared receiver Device；250th, control device；300th, start and stop protection circuit；310th, stopping detecting circuit is opened；320th, counting circuit；330th, time-delay reset electricity Road；340th, on-off circuit；400th, start stop signal input circuit.

Embodiment

The utility model is described in further detail below in conjunction with accompanying drawing.

With reference to shown in Fig. 1 and Fig. 2, a kind of air-conditioning draught fan, including the spiral case 3 with air inlet 1 and air outlet 2, located at snail The both sides of shell 3 are used on the rectangular frame 4 for supporting spiral case 3, rectangular frame 4 be provided with cross bar 5 and montant 6, the two ends difference of cross bar 5 It is connected on rectangular frame 4, the two ends of montant 6 are connected on cross bar 5 and rectangular frame 4, to cause cross bar 5 and the shape of montant 6 Bearing block 7 is installed into T-shaped, and on tie point between cross bar 5 and montant 6.

Impeller 8 and the motor 9 for driving impeller 8 to rotate are installed in spiral case 3, motor 9 is external rotor electric machine 9, It is connected to respectively by bearing on bearing block 7 on the two ends of motor 9.Guard assembly 200, guard assembly 200 are connected with motor 9 It is connected with the start-up circuit 100 of motor 9 including housing 210 and in housing 210, the start-up circuit 100 for electricity The starting switch SB2 and closing switch SB1 of the start and stop of machine 9, referring to such as Fig. 3；Press starting switch SB1,8 turns of the impeller of driving of motor 9 It is dynamic, fresh air is sucked from air inlet 1, and is blown out from air outlet 2.

With reference to shown in Fig. 1 and Fig. 2, the casing 10 for being coated on outside spiral case 3 is connected between both sides rectangular frame 4, Casing 10 includes foreboard 101, back plate 102, top plate 103, bottom plate 104 and side plate 105, and side plate 105 is used for sealed rectangular framework 4 With the gap between spiral case 3, Sound-proof material 11 is filled between casing 10 and spiral case 3, the setting of Sound-proof material 11 can be in motor When 9 driving impellers 8 are rotated, the effectively outflow of reduction noise.

As shown in figure 3, start stop signal input circuit 200 is coupled with start-up circuit 100, the start stop signal input circuit It is coupled with 200 for preventing the start and stop protection circuit 300 of the frequent starting of motor 9.

As shown in figure 4, start and stop protection circuit 300 includes：

Stopping detecting circuit 310 is opened, it has input and output end, for detecting the start and stop letter inputted in its input When number Vz is located at rising edge or trailing edge, the corresponding detection signal Vq of its output end output；

Counting circuit 320, it has input, output end and reset terminal, and the input of the counting circuit 320 is coupled to The output end of stopping detecting circuit 310 is opened, and is counted and after the full pre-determined number of meter from its output in response to detection signal Vq The corresponding count signal Vj of end output；

Time-delay reset circuit 330, it has triggering end and output end, and the triggering end of the time-delay reset circuit 330 is coupled to The output end of counting circuit 320, and enter line delay in response to count signal Vj, corresponding time-delay reset is exported after preset time Signal Vy to counting circuit 320 reset terminal；

On-off circuit, it has input and output end, and its input is coupled to counting circuit 320 with count pick up signal Vj, and export corresponding switching signal from its output end；

The K1 of relay one, its normally-closed contact K1-1 is serially connected on the start-up circuit 100 of motor 9, and its coil is coupled to switch The output end of circuit controls in response to switching signal its normally-closed contact K1-1 break-make to receive switching signal.

AC/DC converters are also associated with the start-up circuit 100 of motor 9, AC/DC converters are used to provide start and stop protection Circuit 300, the K1 of relay one stable operating voltage Vcc.

As shown in figure 3, start stop signal input circuit 200 includes：Current transformer, it has input and output end, its Input is coupled on the start-up circuit 100 of motor 9, and exports corresponding mutual inductance current value from its output end；Rectifier bridge, it has There are input and output end, its input is coupled in the output end of current transformer；Load resistance, it is coupled to rectifier bridge In output end, to export corresponding start stop signal Vz to opening stopping detecting circuit 310.

As shown in figure 5, opening stopping detecting circuit 310 includes two block registers（U1、U2）, the first not circuit Y1, first with Gate circuit F1, the second not circuit Y2, second and gate circuit F2 and OR circuit H1.

Two block registers（U1、U2）Clock end CP and reset terminal CL give corresponding clock signal clk by external chip With reset signal rst, the present embodiment no longer specifically deploys explanation.

First not circuit F1 input is coupled to rear stage register U2 output end Q；Second not circuit F2's Input is coupled to previous stage register U1 output end Q；First be coupled to gate circuit Y1 one of input it is previous Level register U1 output end Q, another input is coupled to the first not circuit F1 output end；Second with gate circuit Y2's One of output end is coupled to the second not circuit F2 output end, and another input is coupled to rear stage register U2's Output end Q；OR circuit H1 two inputs are respectively coupled to first and gate circuit Y1 and second and gate circuit Y2.

It is high level that one-shot switch SB2, start stop signal Vz, which is pressed, by original low transition；By closing next time SB1 is switched, start stop signal Vz is low level by original high level saltus step, therefore there is a rising edge and trailing edge.

Wherein, register U2 is latched to latch incoming level when start stop signal Vz rising edges arrive, register U1 Firmly next start stop signal Vz saltus step（Trailing edge）Incoming level during arrival, if the two registers（U1、U2）Latch Level signal firmly is different, and edge, i.e. rising edge or trailing edge are detected with regard to explanation.

Therefore, when pressing starting switch SB2, when start stop signal Vz has rising edge, first is high electric with gate circuit Y1 outputs Flat rising edge detection signal Vs, conversely, closing switch SB1 ought be pressed again, when there is trailing edge in start stop signal Vz, second with The trailing edge detection signal Vx of gate circuit Y2 output high level；Rising edge detects that signal Vs and trailing edge detection signal Vx are input to After OR circuit H1, OR circuit H1 can export the detection signal Vq of high level.

As shown in fig. 6, counting circuit 320 uses counter.The input in of counting circuit 320 is coupled to start and stop detection electricity Output end (the i.e. OR circuit H1 output end on road 310）To receive detection signal Vq.Counting circuit 320 often receives once high The detection signal Vq of level, then carry out a number, and the present embodiment is preferably when counting completely twice, from the high electricity of its output end out outputs Flat count signal Vj.

As shown in fig. 7, time-delay reset circuit 330 is integrated using 555 timing chips.

Input to NPN type triode Q1 base stage, turn it in count signal Vj, and then 555 timing chips are powered.It is logical When electric, voltage vcc is charged to electric capacity C1, forms charging current, and the electric current is flowed through after resistance R2, and electricity is formed in resistance R2 upper end Pressure, the voltage is higher than the triggering level of the pin of 555 timing chip 2, and therefore, 555 timing chips are not triggered.When electric capacity C1 is fully charged When, charging current disappears so that the loss of voltage of resistance R2 upper ends, so as to trigger 2 pin of 555 timing chips, 555 timing chips 3 pin export high level time delayed signal Vy.Time delayed signal Vy is delivered to the reset terminal rst of counting circuit 320, so as to count Circuit 320 resets.

As shown in figure 8, on-off circuit 340 includes：3rd resistor R3, its one end is coupled to the output end of counting circuit 320 out；4th resistance R4, its one end is coupled to the 3rd resistor R3 other end, its other end ground connection；Second triode Q2, its base Pole is coupled on the tie point between 3rd resistor R3 and the 4th resistance R4, and its grounded emitter, its colelctor electrode is coupled to relay Voltage vcc is connected after the K1 of device one coil；Diode D1, its two ends inverse parallel is at the K1 of relay one coil two ends.

The course of work：

When counting completely twice（Represent that motor 9 completes a shutdown process）, NPN type triode Q2 base stage receives high electricity Flat, triode Q2 conductings, the K1 of control relay one coil obtains electric, disconnects its normally-closed contact K1-1 so that the startup electricity of motor 9 Road 100 is in off state, and motor 92 can not be started by now pressing starting switch SB2；After preset time, time-delay reset circuit Counting circuit 320 is promoted to reset, NPN type triode Q2 base stage receives low level count signal Vj, triode Q2 cut-off, control The K1 of relay one processed coil losing electricity, normally-closed contact K1-1 closures so that the start-up circuit 100 of motor 9 is in channel status, electricity Machine 9 can be activated switch SB2 and start.

With reference to shown in Fig. 1 and Fig. 9, guard assembly 200 also includes storage tank 220, infrared receiver 230, infrared ray hair Emitter 240, control device 250 and the K2 of relay two.

Storage tank 220 is on the outer wall of housing 210.

RF transmitter 230 is located on the side cell wall of storage tank 220 to send infrared light；Infrared receiver 240 It is oppositely arranged to receive infrared light and output is corresponding with RF transmitter 230 on the opposite side cell wall of storage tank 220 Infrared detection signal.The circuit diagram of RF transmitter 230 and infrared receiver 240 is as shown in Figure 9.

Control device 250 is coupled to infrared receiver 240 and detects signal with receiving infrared-ray, and exports corresponding control Signal.

The K2 of relay two has the first normally opened contact K2-1 and the second normally opened contact K2-2, its first normally opened contact K2-1 strings It is connected on start-up circuit 100, its coil is coupled to control device 250 to receive control signal, and in response to control signal to control Make its first normally opened contact K2-1 break-make, its second normally opened contact K2-2 be connected in parallel on control device 250 with control after The K2 of electrical equipment two is in self-locking state.

And reset switch SB3 is coupled with the current supply circuit of the control device 250, reset switch SB3 is pressed to disconnect The K2 of relay two current supply circuit, for releasing the K2 of relay two self-locking state.

Wherein, control device 250 includes triode Q3, and its base stage is coupled to the output end of infrared receiver 240, and it is sent out Emitter grounding, its colelctor electrode is coupled to voltage vcc after being coupled to the K2 of relay two coil；Diode D3, the two of diode D3 Inverse parallel is held at the two ends of the K2 of relay two coil.

, it is necessary to which operating personnel are manually placed to separate infrared emitting in the storage tank 220 before the air-conditioning draught fan is started The infrared light that device 230 is sent so that infrared receiver 240 can not receive the infrared light that RF transmitter 230 is sent, from And infrared receiver 240 will export the infrared detection signal of high level to triode Q3 base stage, triode Q3 conductings, control The K2 of relay two processed coil obtains electric, inhales and its first normally opened contact K2-1 so that the current supply circuit of start-up circuit 100 is in and led Logical state, to meet the condition for starting motor 9 by starting switch SB2.

And now, the K2 of relay two the second normally opened contact K2-2 closures, to cause the K2 of relay two to be in self-locking shape State, also accordingly causes the K2 of relay two to be in obtain electricity condition to ensure that operating personnel's hand departs from from storage tank 220.

Closing switch SB1 is being pressed, is being closed down after the air-conditioning draught fan, accordingly can press reset switch SB3 to release relay Two K2 self-locking state.

By RF transmitter 230, infrared receiver 240, control device 250 and the K2 of relay two setting, with Further prevent the air-conditioning draught fan by frequent starting.

Described above is only exemplary embodiment of the present utility model, not for limitation protection model of the present utility model Enclose, protection domain of the present utility model is determined by appended claim.

Claims (10)

1. a kind of air-conditioning draught fan, including the spiral case (3) with air inlet (1) and air outlet (2), the impeller in spiral case (3) (8) and for drive the impeller (8) rotate motor (9), it is characterized in that：Guard assembly is connected with the motor (9) (200), the guard assembly (200) includes the start-up circuit of housing (210) and the motor (9) in housing (210) (100) starting switch and closing switch for motor (9) start and stop, the start-up circuit, are connected with the start-up circuit (100) (100) start stop signal input circuit (400) is coupled with, is coupled with the start stop signal input circuit (400) for preventing electricity The start and stop protection circuit (300) of machine (9) frequent starting, the start and stop protection circuit (300) includes：

Stopping detecting circuit (310) is opened, it has input and output end, for detecting the start stop signal inputted in its input During positioned at rising edge or trailing edge, the corresponding detection signal of its output end output；

Counting circuit (320), it has input, output end and reset terminal, and the input of the counting circuit (320) is coupled to The output end of stopping detecting circuit (310) is opened, and is counted and after the full pre-determined number of meter from its output in response to detection signal The corresponding count signal of end output；

Time-delay reset circuit (330), it has triggering end and output end, and the triggering end of the time-delay reset circuit (330) is coupled to The output end of counting circuit (320), and enter line delay in response to count signal, corresponding time-delay reset is exported after preset time Signal to counting circuit (320) reset terminal；

On-off circuit (340), it has input and output end, and its input is coupled to counting circuit (320) with count pick up Signal, and export corresponding switching signal from its output end；

Relay one, its normally-closed contact is serially connected on the start-up circuit of motor (9) (100), and its coil is coupled to on-off circuit Output end controls in response to switching signal the break-make of its normally-closed contact to receive switching signal.

2. a kind of air-conditioning draught fan according to claim 1, it is characterized in that：The start stop signal input circuit (400) includes：

Current transformer, it has input and output end, and its input is coupled on the start-up circuit of motor (9) (100), and Corresponding mutual inductance current value is exported from its output end；

Rectifier bridge, it has input and output end, and its input is coupled in the output end of current transformer；

Load resistance, it is coupled in the output end of rectifier bridge, to export corresponding start stop signal to opening stopping detecting circuit (310)。

3. a kind of air-conditioning draught fan according to claim 1, it is characterized in that：The stopping detecting circuit (310) that opens is including two pieces Register, the first not circuit, first and gate circuit, the second not circuit, second and gate circuit and OR circuit；Described The input of one not circuit is coupled to the output end of rear stage register；Before the input of second not circuit is coupled to The output end of one-level register；Described first is coupled to the output of previous stage register with one of input of gate circuit End, another input is coupled to the output end of the first not circuit；Described second with one of output end coupling of gate circuit The output end of the second not circuit is connected to, another input is coupled to the output end of rear stage register；The OR circuit Two inputs be respectively coupled to first and gate circuit and second and gate circuit.

4. a kind of air-conditioning draught fan according to claim 1, it is characterized in that：The counting circuit (320) uses counter.

5. a kind of air-conditioning draught fan according to claim 1, it is characterized in that：The time-delay reset circuit (330) is determined using 555 When integrated chip.

6. a kind of air-conditioning draught fan according to claim 1, it is characterized in that：The on-off circuit (340) includes：

3rd resistor, its one end is coupled to the output end of counting circuit (320)；

4th resistance, its one end is coupled to the other end of 3rd resistor, its other end ground connection；

Second triode, its base stage is coupled on the tie point between 3rd resistor and the 4th resistance, its grounded emitter, and it collects Electrode connects voltage vcc after being coupled to the coil of relay one；

Diode, its two ends inverse parallel is at the coil two ends of relay one.

7. a kind of air-conditioning draught fan according to claim 1, it is characterized in that：The air-conditioning draught fan also includes being located at spiral case (3) two Side is used to be provided with cross bar (5) and montant (6), the horizontal stroke on the rectangular frame (4) for supporting spiral case (3), the rectangular frame (4) Bearing block (7) for fixing motor (9) rotating shaft is installed on the tie point between bar (5) and montant (6).

8. a kind of air-conditioning draught fan according to claim 7, it is characterized in that：Being connected between both sides rectangular frame (4) is used for The outside casing (10) of spiral case (3) is coated on, Sound-proof material (11) is filled between the casing (10) and spiral case (3).

9. a kind of air-conditioning draught fan according to claim 1, it is characterized in that：The guard assembly (200) also includes：

Storage tank (220), it is on the outer wall of housing (210)；

RF transmitter (230), it is located on the side cell wall of storage tank (220) to send infrared light；

Infrared receiver (240), it is relative with RF transmitter (230) on the opposite side cell wall of storage tank (220) Set to receive infrared light and export corresponding infrared detection signal；

Control device (250), it is coupled to infrared receiver (240) and detects signal with receiving infrared-ray, and exports corresponding Control signal；

Relay two, there is the first normally opened contact to be serially connected on start-up circuit for it, and its coil is coupled to control device to receive control Signal processed, and in response to control signal to control the break-make of its first normally opened contact.

10. a kind of air-conditioning draught fan according to claim 9, it is characterized in that：The relay two is also normally opened tactile with second Point, the described second normally opened touch is connected in parallel on control device (250) with control relay two in self-locking state.