CN206595912U

CN206595912U - A kind of inverter pre-driver circuitry controlled with overcurrent protection

Info

Publication number: CN206595912U
Application number: CN201720274442.4U
Authority: CN
Inventors: 刘文彬; 冼镜潮; 苏松得
Original assignee: GUANGDONG LIANGDE OPTOELECTRONICS TECHNOLOGY CO LTD
Current assignee: GUANGDONG LIANGDE OPTOELECTRONICS TECHNOLOGY CO LTD
Priority date: 2017-03-21
Filing date: 2017-03-21
Publication date: 2017-10-27
Anticipated expiration: 2027-03-21

Abstract

The utility model embodiment discloses a kind of inverter pre-driver circuitry controlled with overcurrent protection, including DC boosting loop, DC inversion loop, PWM control loops, protective loop, the DC boosting loop includes power transformer, first power switch pipe, the push-pull circuit of second power switch pipe composition, first power switch pipe, the source electrode of second power switch pipe is connected to sampling resistor, the protective loop obtains sampled voltage from the sampling resistor, and input in-phase amplifier and the output switching signal control PWM control loops output drive signal after self-locking comparator.Using the utility model, the detection sampled to periodic current one by one, compare, protect, controlled and protection act flow.Add current sampling circuit in circuit, current signal amplifier circuit compares and is delayed, output protection signal and latching circuit, prevents circuit from damaging prime power MOS pipe in booting moment, effectively improves the quality of product.

Description

A kind of inverter pre-driver circuitry controlled with overcurrent protection

Technical field

The utility model is related to before a kind of protection circuit of inverter, more particularly to a kind of inverter controlled with overcurrent protection Stage drive circuit.

Background technology

At present, output voltage waveforms are also required that close to civil power using more and more for small portable inverter.Though The right most of inverter products of in the market in output waveform with real requirement can be met in power efficiency, but in band different loads Impact and product start impact in terms of just become not being fine.Although many products use soft start function, Because the time of soft start compares section；Starting moment, due to secondary filter capacitor charging near short circuit, inversion when causing to start Device primary high current input, often has the tolerance range that peak current exceeds power MOS that starts of moment, prime power MOS is rushed Hit larger；And the product on existing market lacks front stage circuits power MOS is protected, cause product in booting moment, damage Bad prime power MOS, causes machine failure.

The content of the invention

The utility model embodiment technical problem to be solved is that there is provided a kind of inverter controlled with overcurrent protection Pre-driver circuitry.The impact that inverter is started shooting and load change is caused can be overcome, inverter is effectively protected.

In order to solve the above-mentioned technical problem, the utility model embodiment provides a kind of inverter controlled with overcurrent protection Pre-driver circuitry, including DC boosting loop, the DC inversion that circuit output voltage progress ac converter is risen to the direct current Loop, PWM control loops, protective loop, the DC boosting loop include power transformer, the first power switch pipe, second The push-pull circuit of power switch pipe composition, first power switch pipe, the source electrode of the second power switch pipe are connected to sampling electricity Resistance, the protective loop obtains sampled voltage from the sampling resistor, and input in-phase amplifier with it is defeated after self-locking comparator Going out switching signal controls the PWM control loops to provide drive signal for first power switch pipe, the second power switch pipe.

Further, be connected with turn between the secondary windings positive-negative output end of the power transformer the first diode, First supercharging electric capacity, the second supercharging electric capacity, the second diode, the centre cap of the secondary windings of the power transformer are connected to Between the first supercharging electric capacity, the second supercharging electric capacity.

Further, the protective loop also includes optical coupler, the photophore of the optical coupler and three end adjustable shunts A reference source is concatenated, and the reference pole of three end adjustable shunt reference source is sampled from the DC boosting output voltage loop, The protective loop has comparison circuit, and the light-receiving device of the optical coupler is used to lift the input terminal voltage of the comparison circuit Height, makes the PWM control loops reduce dutycycle output.

Further, in addition to output loop, the output loop is included to DC inversion loop output current The LC filter circuits being filtered, and carry out the common mode inductance of EMI filtering.

Implement the utility model embodiment, have the advantages that：Front stage circuits of the utility model to inverter circuit Design is optimized, the detection sampled using periodic current one by one, compare, protect, controlled and protection act flow.In circuit Add current sampling circuit, current signal amplifier circuit compares and is delayed, output protection signal and latching circuit, prevents electricity Prime power MOS pipe is damaged in road in booting moment, effectively improves the quality of product.

Brief description of the drawings

Fig. 1 is the electrical block diagram of DC boosting loop of the present utility model, inversion circuit and output loop；

Fig. 2 is the electrical block diagram of PWM control loops and protective loop；

Fig. 3 is the electrical block diagram of the optical coupler part of protective loop.

Embodiment

It is new to this practicality below in conjunction with accompanying drawing to make the purpose of this utility model, technical scheme and advantage clearer Type is described in further detail.

Electrical block diagram shown in reference picture 1, Fig. 2.

A kind of inverter pre-driver circuitry controlled with overcurrent protection of the utility model embodiment, including DC boosting Loop, DC inversion loop, PWM control loops, protective loop, output loop.

As shown in figure 1, DC boosting loop includes power transformer TI, the first power switch pipe Q10, the second power switch Pipe Q12, diode D8, D11 composition push-pull circuit, in the present embodiment, the first power switch pipe Q10, the second power switch Increasing superpower power switch pipe Q11, the Q13 for going back and being connected on pipe Q12, power switch pipe is metal-oxide-semiconductor.

In order to carry out over-current detection to the driving of the prime in DC inversion loop, the utility model is in the first power switch pipe Q10, the second power switch pipe Q13 source electrode are connected to sampling resistor R50, R51.

As shown in Fig. 2 protective loop has the in-phase amplifier U2B and self-locking comparator U2A being sequentially connected, with mutually amplification Device U2B input sample resistance R50, R51 sampled voltage, are more than self-locking after sampled voltage amplifies through in-phase amplifier U2B During comparator U2A reference voltage 5V, controller U1 of the output switching signal to PWM control loops makes PWM output terminals As, B defeated Go out low level, the push-pull circuit in DC boosting loop is stopped, so as to occur when protecting inversion circuit prime electric current excessive Exception.

It is connected with the first diode D5, the first supercharging electric capacity between the secondary windings positive-negative output end of power transformer in turn C16, the second supercharging electric capacity C17, the second diode D12, the centre cap of secondary windings are connected to the first supercharging electric capacity C16, the Between two supercharging electric capacity C17 so that secondary windings is exported with multiplication of voltage, reduces power consumption.

As shown in figure 3, protective loop also includes optical coupler, the photophore U4A of optical coupler and three end adjustable shunt reference sources U5 is concatenated, and three end adjustable shunt reference source U5 are TL431, and it is connected between resistance R30, R31 with reference to pole, and resistance R30 is from straight Stream boosting output voltage loop is sampled, and when voltage output is abnormal, three end adjustable shunt reference source U5 pull-down currents make Photophore U4A is luminous, and light-receiving device U4B correspondences are turned on, and REF ends is turned on EMI ends, and the controller U1 of protective loop is with interior The comparison circuit put, as shown in Fig. 2 when REF ends and EMI ends are turned on, the voltage rise at EMI ends makes the negative terminal electricity of comparator Pressure rise, internal comparator action, control output PWM dutycycle diminishes, and reduces the output voltage in DC boosting loop.

For another example Fig. 1, output loop includes the LC filter circuits being filtered to DC inversion loop output current, carries out The common mode inductance L2 of EMI filtering.

In the utility model embodiment, DC inversion loop is using general existing inversion circuit, the utility model Current detecting is carried out in pre-driver circuitry, prevents electric current from being damaged caused by excessive, and to the output electricity in DC boosting loop Pressure is detected, makes the stabilized input voltage of inversion circuit, so as to improve the life-span of product.

Certain above-described embodiment is only to illustrate technical concepts and features of the present utility model, and its object is to allow be familiar with this The people of technology can understand content of the present utility model and implement according to this, and protection model of the present utility model can not be limited with this Enclose.The modification that all Spirit Essences according to the utility model main technical schemes are done, should all cover and be protected of the present utility model Within the scope of shield.

Claims

1. a kind of inverter pre-driver circuitry controlled with overcurrent protection, it is characterised in that including DC boosting loop, to institute State direct current and rise circuit output voltage and carry out the DC inversion loop of ac converter, PWM control loops, protective loop, the direct current Boosting loop includes power transformer, the first power switch pipe, the push-pull circuit of the second power switch pipe composition, described first Power switch pipe, the source electrode of the second power switch pipe are connected to sampling resistor, and the protective loop is obtained from the sampling resistor Sampled voltage, and input output switching signal after in-phase amplifier and self-locking comparator and control the PWM control loops to be described First power switch pipe, the second power switch pipe provide drive signal.

2. the inverter pre-driver circuitry according to claim 1 controlled with overcurrent protection, it is characterised in that the work( It is connected with the first diode, the first supercharging electric capacity, the second supercharging electricity between the secondary windings positive-negative output end of rate transformer in turn Appearance, the second diode, the centre cap of the secondary windings of the power transformer are connected to the first supercharging electric capacity, the second increasing Between voltage capacitance.

3. the inverter pre-driver circuitry according to claim 1 or 2 controlled with overcurrent protection, it is characterised in that institute Stating protective loop also includes optical coupler, and the photophore of the optical coupler is concatenated with three end adjustable shunt reference sources, and three end can The reference pole of shunt reference source is adjusted to be sampled from the DC boosting output voltage loop, the protective loop has relatively more electric Road, the light-receiving device of the optical coupler is used to raise the input terminal voltage of the comparison circuit, reduces the PWM control loops Dutycycle is exported.

4. the inverter pre-driver circuitry according to claim 3 controlled with overcurrent protection, it is characterised in that also include Output loop, the output loop includes the LC filter circuits being filtered to DC inversion loop output current, and Carry out the common mode inductance of EMI filtering.