CN203243267U

CN203243267U - Major loop circuit of two-phase direct current brushless temperature control fan

Info

Publication number: CN203243267U
Application number: CN 201320243506
Authority: CN
Inventors: 蔡忠英
Original assignee: KINGSKY ELECTRIC DEQING CO Ltd
Current assignee: KINGSKY ELECTRIC DEQING CO Ltd
Priority date: 2013-05-06
Filing date: 2013-05-06
Publication date: 2013-10-16
Anticipated expiration: 2023-05-06

Abstract

The utility model discloses a major loop circuit of a two-phase direct current brushless temperature control fan. The major loop circuit comprises an A-phase winding and a B-phase winding, a power MOSFET tube Q6 and a power MOSFET tube Q7. The A-phase winding is in serial connection with the power MOSFET tube Q6, the B-phase winding is in serial connection with the power MOSFET tube Q7, an RC adsorption circuit are separately in parallel connection with two ends of the A-phase winding and two ends of the B-phase winding so as to supply a freewheeling loop for the windings. The major loop circuit of a two-phase direct current brushless temperature control fan only comprises two power tubes, a few resistors and a capacitor discrete elements, enables the motor to be effectively driven, and is simple in circuit structure, low in power consumption and low in cost, so that power consumption and cost of a direct current brushless temperature control fan are effectively reduced.

Description

A kind of main loop circuit of two-phase brush DC temperature-controlled fan

Technical field

The utility model relates to the electric machines control technology field, specifically the control of two-phase half-wave brushless direct-current temperature-controlled fan and the design of protective circuit.

Background technology

Fan is widely used in the ventilation and heat field, such as the household electric fan, and computer to dissipate heat fan, automobile engine heat radiation fan.The product such as computer, automobile engine is along with its power consumption of lifting of performance also is accompanied by rising, the higher heat of corresponding generation, these equipment are often owing to the reason of structure and environment for use, can't rely on self-radiating, cause temperature to rise, thereby affect performance and the useful life of properties of product, at this moment just need fan to carry out forced heat radiation.

The caloric value of equipment is determined by the operating state of equipment, the state difference, and load is different, and then caloric value is different.Caloric value and radiating rate reach a poised state, then can holding temperature stable.When not having fan to force heat radiation, the equipment towards periphery speed of space heat elimination almost is certain, the equipment heating amount is not fixed, when working in higher load condition, caloric value rises, and needs to improve rotation speed of the fan to improve radiating rate, when equipment works in low load condition, rotation speed of the fan is too high to have little significance to heat radiation, and the power consumption rising, at this moment need reduce rotation speed of the fan to save electric energy.

Two-phase brushless DC motor configurations and single-phase similar, but operational mode is different, single-phase brushless direct-current motor only has a winding, adopt H bridge all-wave to drive, two phase brushless DC motors adopt the operation of two-phase half-wave, and inverter circuit only is made of two power tubes, save two power tubes than single-phase H bridge, cost is lower, and drive circuit is simple.Two phase brushless DC motors use the asymmetrical airgaps structure that cogging torque zero point and electromagnetic torque are staggered zero point, and motor obtains the self-starting ability.The starting torque of two-phase brushless electric machine is less, is suitable for very much the low starting torque load of this class of fan.

Temperature-controlled fan in the market uses two kinds of modes of speed regulation usually, one class adopts external general purpose controller change motor supply power voltage to carry out speed governing, and the motor controlling integrated circuit of another kind of employing special use produces the temperature variant PWM ripple of duty ratio and carries out electric machine speed regulation.External controller needs extra installing space, and power consumption own is also larger, and then cost is higher to adopt the motor special control chip, is difficult for marketing.

Along with industrial expansion, the consumption of the energy is increasing, the energy-saving and cost-reducing market common recognition that become of product, and the use amount of radiator fan is very big, and the energy equivalence of consumption is considerable.Automatically regulate the rotating speed of fan according to the height of device temperature and realize temperature control, not only can keep the substantially constant of equipment working temperature, and can reduce noise, energy savings, the useful life of prolongation radiator fan.The control circuit of existing temperature-controlled fan is complicated, and used universal or special control chip price is higher, has limited the marketing of temperature-controlled fan, so a kind of temperature-controlled fan with low cost, that power consumption is lower of development and Design is significant.

The utility model content

The purpose of this utility model is to provide the main loop circuit of the brushless temperature-controlled fan of two-phase half-wave DC of a kind of low cost, low-power consumption, has simplified greatly the circuit structure of temperature-controlled fan, has reduced the cost of temperature-controlled fan.

In order to reach above-mentioned target, the technical solution of the utility model is:

A kind of main loop circuit of two-phase brush DC temperature-controlled fan, comprise: A phase winding and B phase winding, and two power MOSFET tubes, the A phase winding is connected with power MOSFET tube Q6, the B phase winding is connected with power MOSFET tube Q7, the two ends of A phase winding and B phase winding all are parallel with the RC absorbing circuit, for winding provides continuous current circuit.

Described power MOSFET tube is P type power MOSFET tube, and inside carries fly-wheel diode.

The brushless temperature-controlled fan main loop circuit of two-phase half-wave DC of the present utility model is only by two power tubes, and a few resistance, electric capacity discrete component form, and have realized effective driving of motor, circuit structure is simple, low in energy consumption, cost is low, effectively reduces brush DC temperature-controlled fan power consumption and cost.

Description of drawings

Fig. 1 is temperature-controlled fan main loop circuit figure.

Fig. 2 is four utmost points, two phase brushless DC motor schematic diagrames.

Fig. 3 is motor-drive circuit block diagram of the present utility model.

Fig. 4 is motor-driven implementation circuit of the present utility model.

Embodiment

Such as Fig. 1, a kind of main loop circuit of two-phase brush DC temperature-controlled fan, comprise: A phase winding and B phase winding, and two power MOSFET tube Q6, Q7, the A phase winding is connected with power MOSFET tube Q6, the B phase winding is connected with power MOSFET tube Q7, and the two ends of A phase winding and B phase winding all are parallel with the RC absorbing circuit, for winding provides continuous current circuit.

Two phase brushless DC motors that radiator fan drives usefulness generally adopt outer-rotor structure, the two-phase independent winding is arranged, as shown in Figure 2, the yoke of rotor 11 directly places in the wind wheel die cavity, the rotation of drive wind wheel, motor stator 12 is formed by silicon steel plate stacking, comprises the winding on insulation coil holder and the winding insulation coil holder; The rotor permanent magnet N utmost point 13, the rotor permanent magnet S utmost point 14, magnetic pole are at the rotor yoke medial surface, and N, the S utmost point are alternately placed; The present embodiment is four utmost points, two phase brushless DC motors, per two over against stator poles on coil 15 consist of a phase winding, A phase stator tooth staggers mutually with B phase stator tooth.Two phase windings of motor are connected with two power MOSFET tubes respectively, the A phase winding is connected with power MOSFET tube Q6, the B phase winding is connected with power MOSFET tube Q7, the two-phase half-wave inverter circuit that forms thus only needs two switching tubes, compare with the H bridge inverter circuit, saved the switching tube of half, reduced cost, because switching tube quantity is few, reduced the power consumption of switching tube simultaneously.Power MOSFET tube is P channel metal-oxide field effect transistor, and namely P type MOSFET compares PNP transistor, and power is higher, can drive the fan of relatively high power.

Each only has phase winding energising constantly two phase brushless DC motors, and another phase winding is unsettled.Hall element is that the phase change logic circuit improves commutation signal, when the central lines of rotor magnetic pole center line and stator tooth, the beginning commutation, the requirement that turns to according to motor, disconnect the power MOSFET tube of conducting, stop corresponding windings power supply, another power tube of conducting, to another winding power supply, realize the continuous operation of motor.As shown in Figure 1; the winding two ends of motor are the RC absorbing circuit that is comprised of resistance R 6, capacitor C 7 and resistance R 7, capacitor C 8 in parallel respectively; for the winding current of stopping power supply provides continuous current circuit, the peak voltage that produces in the inhibition commutation process, protection power MOSFET tube.

As shown in Figure 3, be the circuit block diagram of temperature-controlled fan.Saw-toothed wave generator is an auto-excitation type signal generator that is made of operational amplifier, produces the certain sawtooth waveforms of frequency.The winding resistance of motor is generally less, and during direct-on-line starting, starting current is larger, easily burns out motor.For improving the fan reliability, reach life-saving, designed soft starting circuit.Soft starting circuit is the RC circuit, and during starting, the voltage signal that the output of RC circuit is risen gradually behind signal synthesis, compares with sawtooth waveforms, produces the PWM ripple that duty ratio rises gradually, has reduced the excessive impact to motor of starting current.After starting was finished, soft starting circuit no longer played a role.Output signal among Fig. 3 drives signal 1 and drives signal 2 and outputs to respectively two corresponding power MOSFET tubes, the turn-on and turn-off of power ratio control pipe, thus realize the automatic control of temperature, current limliting and the soft start of motor.

Thermistor is realized the sampling to ambient temperature, and temperature detecting unit is exported temperature variant voltage signal according to the difference of temperature.The voltage signal of reaction temperature and sawtooth waveforms relatively produce the PWM ripple of corresponding duty ratio.In order to simplify circuit, reduce the quantity of components and parts, use the Hall element that two signal output parts are arranged.After the hall signal of the two-way reaction motor rotor position that PWM ripple and Hall element provide was comprehensive, conducting and the shutoff of control corresponding power MOSFET pipe to improve or to reduce the rotating speed of motor, realized the automatic control of temperature.

Among Fig. 4, resistance R 1, capacitor C 1 have consisted of soft starting circuit and temperature sensing circuit with thermistor NTC.During starting, voltage VCC is capacitor C 1 charging, and capacitor C 1 both end voltage rises gradually, after stable, resistance R 1 bleeder circuit of connecting with thermistor NTC formation, thermistor NTC electrical resistance temperature and becoming, under the different temperatures, get different voltages, produce the PWM ripple of different duty.

When motor rotation blockage, can flow through larger electric current on the winding, cut off the electricity supply as untimely, motor overheating is damaged.Designed the current limliting unit for this reason, at the motor main circuit stator winding current sampling resistor Rs that connected, sample rate current signal input current limliting unit, compare with the maximum current set point, when the motor winding current surpasses the setting lowest high-current value, current limliting unit output low level signal blocks the output of PWM ripple, stops the power supply to motor.The current value ratio integrated operational amplifier that carries out that the current limliting unit is used is LM339.

All circuit only is comprised of the minority discrete component, greatly reduces the cost of temperature-controlled fan.

Claims

1. the main loop circuit of a two-phase brush DC temperature-controlled fan, it is characterized in that, comprise: A phase winding and B phase winding, and two power MOSFET tubes, the A phase winding is connected with power MOSFET tube Q6, the B phase winding is connected with power MOSFET tube Q7, and the two ends of A phase winding and B phase winding all are parallel with the RC absorbing circuit, for winding provides continuous current circuit.

2. the main loop circuit of a kind of two-phase brush DC temperature-controlled fan according to claim 1 is characterized in that, described power MOSFET tube is P type power MOSFET tube, and inside carries fly-wheel diode.