Portable vehicle-mounted inverter

Abstract

The embodiment of the utility model provides a portable vehicle-mounted inverter. The portable vehicle-mounted inverter comprises a key control circuit, an inverter pre-stage circuit and an inverter post-stage circuit, the key control circuit is used for electrically coupling the inverter pre-stage circuit and controlling the on-off of the inverter pre-stage circuit; the inverter pre-stage circuit is electrically coupled with the direct-current power supply and the inverter post-stage circuit and is used for generating a first PWM signal and a second PWM signal and generating high-frequency alternating-current voltage by controlling the first PWM signal and the second PWM signal; and the inverter post-stage circuit is electrically coupled with the inverter pre-stage circuit through a transformer and is used for converting the high-frequency alternating-current voltage generated by the inverter pre-stage circuit into the alternating-current voltage meeting the requirement. According to the technical scheme, 12V direct current of the automobile storage battery can be converted into 220V alternating current.

Description

Technical Field

[0001] The present application relates to the technical field of inverters, and in particular to a vehicle-mounted inverter. Background Art

[0002] As people have more and more means of transportation, the car inverter power supply, as a DC to AC converter used on the move, will bring a lot of convenience to your life. It is a common automotive electronic equipment, especially popular among travel enthusiasts and street vendors. However, the car inverters currently on the market still have problems such as low compatibility, poor load capacity, and large size.

[0003] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Utility Model Content

[0004] The embodiment of the present application provides a portable vehicle-mounted inverter, which has advantages of stronger compatibility and load carrying capacity, smaller size, etc. than vehicle-mounted inverters on the market, so as to solve or alleviate one or more technical problems mentioned above.

[0005] As one aspect of an embodiment of the present application, an embodiment of the present application provides a portable vehicle-mounted inverter, including: a key control circuit, an inverter front-stage circuit, and an inverter back-stage circuit; the key control circuit is used to electrically couple the inverter front-stage circuit to control the on and off of the inverter front-stage circuit; the inverter front-stage circuit is electrically coupled to a DC power supply and the inverter back-stage circuit to generate a first PWM signal and a second PWM signal, and to generate a high-frequency AC voltage by controlling the first PWM signal and the second PWM signal; the inverter back-stage circuit is electrically coupled to the inverter front-stage circuit through a transformer, and is used to convert the high-frequency AC voltage generated by the inverter front-stage circuit into an AC voltage that meets the requirements.

[0006] Optionally, the inverter front-stage circuit includes: a PWM signal controller, electrically coupled to the key control circuit, for generating a first PWM signal and a second PWM signal; a first signal amplifying circuit, electrically coupled to the PWM signal controller, for amplifying the first PWM signal; a second signal amplifying circuit, electrically coupled to the PWM signal controller, for amplifying the second PWM signal; an AC front-stage circuit, electrically coupled to a DC power supply, the first signal amplifying circuit and the second signal amplifying circuit; wherein, under the control of the amplified first PWM signal and the amplified second PWM signal, the AC front-stage circuit converts the DC voltage provided by the DC power supply into an AC voltage for output to the inverter back-stage circuit.

[0007] Optionally, the inverter post-stage circuit includes: a rectifier and filter circuit, a pulse width modulation circuit and a feedback circuit; the rectifier and filter circuit is electrically coupled to the inverter pre-stage circuit through a transformer, so as to reduce the ripple of the output voltage of the inverter pre-stage circuit; the feedback circuit is electrically coupled to the rectifier and filter circuit and the pulse width modulation circuit, so as to sample the rectifier and filter output voltage to control the pulse width modulation circuit; the pulse width modulation circuit is electrically coupled to the feedback circuit and the rectifier and filter circuit, and under the control of the feedback circuit, converts the rectifier and filter output voltage generated by the rectifier and filter circuit into an AC voltage that meets the requirements.

[0008] Optionally, the first signal amplifying circuit includes: a circuit for generating the amplified first PWM signal and outputting it to the AC pre-stage circuit; the first signal amplifying circuit includes: a transistor Q4 and a transistor Q16; the base of the transistor Q4 and the base of the transistor Q16 are both connected to the key control circuit, the collector of the transistor Q4 is externally connected to a DC power supply, the emitter of the transistor Q4 and the emitter of the transistor Q16, the emitter of the transistor Q4 and the emitter of the transistor Q16 are connected to a common point and electrically coupled to the AC pre-stage circuit and the collector of the transistor Q16. Grounded; and a second signal amplifying circuit: used to generate the amplified second PWM signal and output it to the AC front-stage circuit; the second signal amplifying circuit includes: a transistor Q5 and a transistor Q17, the base of the transistor Q5 and the base of the transistor Q17 are both connected to the key control circuit, the collector of the transistor Q5 is externally connected to a DC power supply, the emitter of the transistor Q5 is connected to the emitter of the transistor Q17, the common point of the emitter of the transistor Q5 and the emitter of the transistor Q17 is electrically coupled to the AC front-stage circuit, and the collector of the transistor Q17 is grounded.

[0009] Optionally, the AC front-stage circuit includes: a transistor Q6, a transistor Q7, and a transformer T1; the transistor Q7: the gate is electrically coupled to the first signal amplification circuit, the drain is electrically coupled to the transformer T1, and the source is grounded; the transistor Q6: the gate is electrically coupled to the second signal amplification circuit, the drain is electrically coupled to the transformer T1, and the source is grounded; the transformer T1 is electrically coupled to the inverter back-stage circuit, and is used to receive the amplified PWM signal and, under the control of the signal, convert the DC voltage provided by the DC power supply into an AC voltage for output to the inverter back-stage circuit.

[0010] Optionally, the rectifier and filter circuit includes: a rectifier circuit and a filter circuit, wherein: the rectifier circuit includes: a diode D3, a diode D4, a diode D5 and a diode D6, the diode D5 and the diode D4 are electrically connected to the same side of the secondary winding of the transformer T1, the diode D3 and the diode D6 are connected to the other side of the secondary winding of the transformer T1, and are electrically coupled to the AC front-stage circuit, for rectifying the AC voltage generated by the AC front-stage circuit and outputting a rectified signal to the filter circuit; wherein the cathode of the diode D3 and the cathode of the diode D5 are connected to form the An output end of the rectifier circuit, the anode of the diode D4 and the anode of the diode D6 are connected to form another output end of the rectifier circuit and are grounded, and the filter circuit includes: a capacitor EC3 and a resistor R1; the capacitor EC3 is connected across the two output ends of the rectifier circuit; one end of the resistor R1 is grounded, and the other end is electrically connected to the output end formed by the cathode of the diode D3 and the cathode of the diode D5; the filter circuit is used to filter the rectified signal to output a filtered signal, and the filter circuit is electrically coupled to the pulse width modulation circuit and the feedback circuit to provide a rectified and filtered output voltage.

[0011] Optionally, the feedback circuit includes: a control integrated circuit; the control integrated circuit is electrically coupled to the rectifier and filter circuit to receive a rectifier and filter signal; and is electrically coupled to the pulse width modulation circuit for controlling the pulse width modulation circuit to generate a desired frequency and waveform according to the rectifier and filter signal.

[0012] Optionally, the feedback circuit further includes: a power supply circuit, and the power supply circuit is used to supply power to the control integrated circuit.

[0013] Optionally, the control integrated circuit includes: a temperature detection circuit, a frequency selection circuit, a voltage detection circuit, an output current detection circuit, and a fan control circuit.

[0014] The above technical solution adopted in the embodiment of the present application may have the following advantages:

[0015] By adopting high-frequency PWM switching power supply technology, the output power of the vehicle inverter is improved, the size of the transformer in the internal circuit of the vehicle inverter is reduced, and the DC power of the car power supply is converted into AC power that meets the requirements, so that the vehicle inverter has stronger compatibility and load capacity, and the size of the vehicle inverter is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0017] Figure 1 It is a schematic diagram of the structure of a portable vehicle-mounted inverter provided in an embodiment of the present application.

[0018] Figure 2 It is a circuit diagram of a key control circuit of a portable vehicle inverter provided in an embodiment of the present application.

[0019] Figure 3 It is a circuit diagram of a PWM signal controller, a first signal amplifying circuit, and a second signal amplifying circuit of a portable vehicle inverter provided in an embodiment of the present application.

[0020] Figure 4 4 is a circuit diagram of an AC front-stage circuit of a portable vehicle-mounted inverter provided in an embodiment of the present application.

[0021] Figure 5 It is a circuit diagram of a rectifier filter circuit and a pulse width modulation circuit of a portable vehicle-mounted inverter provided in an embodiment of the present application.

[0022] Figure 6 4 is a circuit diagram of a feedback circuit of a portable vehicle-mounted inverter provided in an embodiment of the present application. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other in the absence of conflict. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0024] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0025] To facilitate those skilled in the art to understand the technical solutions provided in the embodiments of the present application, the relevant technologies are described below:

[0026] Rectification and filtering technology: The AC signal is converted into a DC signal through a rectification circuit, and then the pulsating component in the DC signal is removed through a filtering circuit to obtain a stable DC signal.

[0027] High-frequency PWM switching power supply technology: The on and off of the switch tube is controlled by a high-frequency PWM (pulse width modulation) signal, thereby converting direct current into high-frequency alternating current.

[0028] To this end, the embodiment of the present application provides a portable vehicle-mounted inverter, based on which the output power of the vehicle-mounted inverter is increased, the volume of the transformer of the internal circuit of the vehicle-mounted inverter is reduced, and the direct current of the vehicle power supply is converted into alternating current that meets the requirements.

[0029] This product uses button SW1, connecting diode D1, transistor Q1 to control the on / off of U5 (TL494IN) to turn on / off the output.

[0030] The inverter front-stage oscillation circuit is formed by the single-chip microcomputer U5 (TL494IN), transformer T1 (EFD30), and transistor Q6 / Q7 (HY3306). J1 is the level interface (12V cigarette lighter port), and J2 is the AC220V output interface. When the button SW1 is turned on, the single-chip microcomputer U5 (TL494IN) is powered by turning on the transistor Q1 (AO3407). The microcontroller U5 (TL494IN) oscillates through PWM through transistors Q4 / Q5, Q16 / Q17, and then forms a pre-stage oscillation circuit through transistors Q6 / Q7 and transformer T1 (EFD30), and then rectifies and outputs through diodes D3 / D4 / D5 / D6 (SF58), and then outputs VBUS voltage (240V) through capacitor EC3 (22uF / 400V) and resistor R1 (200K / 1206).

[0031] The MOS is driven by a 12V power supply composed of transformer T1 (EFD30), rectifier bridge U2 (MB10F), and three-terminal regulator U3 (HT75C0-2). A stable 5V power supply is provided to the subsequent microcontroller U6 (HT66F0175) by a three-terminal regulator U4 (HT7550-2). The VBUS voltage is then passed through microcontroller U6-2 (60Hz / B), microcontroller U6-3 (60Hz / B), transistor Q12 / transistor Q13 / transistor Q14 / transistor Q15, and resistor R41 (UTCUF740L) to form a subsequent oscillation circuit. The microcontroller U6-14 (VFB) detects resistor R52, and resistor R54 divides the voltage to detect the VBUS voltage. The output current is detected by detecting resistors R55, R56, and R41 through rectifier bridge U2-17 (BATV). The transformer temperature is detected by resistor R53, thermistor NTC1, and microcontroller U6-14 (NTC). The output frequency can be set by resistor R43 and resistor R46 (R43=10K / R16=NC output 50HZ, R43=NC / R16=10K output 60HZ). By detecting that all indicators are normal, AC 220V is output.

[0032] When the device detects that the output power is greater than 30W, the microcontroller U6-16, resistor R34, and U1 (EL357C) control the transistor Q3 (AO3400) to control the external fan FAN1 and turn on the fan. When the input exceeds 20A and reaches a certain temperature, the fuse F1 will disconnect the circuit to play a protective role.

[0033] Principle of portable car inverter: Convert 12V DC power from car battery into 220V AC power.

[0034] First, the 12V DC power provided by the car battery is converted into 34kHz, 220V AC power through high-frequency PWM (pulse width modulation) switching power supply technology (microcontroller U5 provides 34kHZ frequency). Then, bridge rectification (diode D3 / diode D4 / diode D5 / diode D6), filtering (capacitor EC3, capacitor C24), pulse width modulation and switching power output (controlling transistor Q12 / transistor Q13 / transistor Q14 / transistor Q15 through microcontroller U6 (HT66F0175)) and other technologies are used to convert the 34kHz, 220V AC power into 50Hz, 220V AC power.

[0035] Hereinafter, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. It should be noted that these exemplary embodiments can be implemented in many different forms and should not be construed as being limited to the embodiments described herein.

[0036] like Figure 1-6As shown, the portable vehicle inverter may include: a key control circuit, an inverter front-stage circuit, and an inverter rear-stage circuit. The key control circuit is used to electrically couple the inverter front-stage circuit to control the on and off of the inverter front-stage circuit; the inverter front-stage circuit is electrically coupled to the DC power supply and the inverter rear-stage circuit to generate a first PWM signal and a second PWM signal, and to generate a high-frequency AC voltage by controlling the first PWM signal and the second PWM signal. The inverter rear-stage circuit is electrically coupled to the inverter front-stage circuit through a transformer to convert the high-frequency AC voltage generated by the inverter front-stage circuit into an AC voltage that meets the requirements.

[0037] Specifically, when the key SW1 of the key control circuit is pressed, a high-level signal will be output, and the inverter front-stage circuit will be turned on. When the key SW1 is released, a low-level signal will be output, and the inverter front-stage circuit will be turned off. The first PWM signal and the second PWM signal are two signals that control the switching time of the switch tubes PMWA and PMWB of the inverter front-stage circuit. The first PWM signal controls the switching time of the first switch tube PMWA of the inverter front-stage circuit, and the second PWM signal controls the switching time of the second switch tube PMWB of the inverter front-stage circuit. When the switch tube is turned on, according to different combinations of the first PWM signal and the second PWM signal, the current will flow through the switch tube PMWA, the switch tube PMWB and the primary winding of the transformer T1, and the inverter front-stage circuit can generate different high-frequency AC voltages; the inverter rear-stage circuit is electrically coupled to the inverter front-stage circuit through the transformer T1, and the high-frequency AC voltage generated by the inverter front-stage circuit is converted into an AC voltage that meets the requirements and outputs it.

[0038] In an optional embodiment, if Figure 3-4 As shown, the inverter front-stage circuit includes: a PWM signal controller, a first signal amplifying circuit, a second signal amplifying circuit, and an AC front-stage circuit. The PWM signal controller is electrically coupled to the key control circuit and is used to generate a first PWM signal and a second PWM signal. The first signal amplifying circuit is electrically coupled to the PWM signal controller and is used to amplify the first PWM signal. The second signal amplifying circuit is electrically coupled to the PWM signal controller and is used to amplify the second PWM signal; the AC front-stage circuit is electrically coupled to a DC power supply, the first signal amplifying circuit, and the second signal amplifying circuit. Wherein, under the control of the amplified first PWM signal and the amplified second PWM signal, the AC front-stage circuit converts the DC voltage provided by the DC power supply into an AC voltage to output to the inverter back-stage circuit.

[0039] Specifically, the PWM signal controller is implemented by a single-chip microcomputer U5, the output end of the single-chip microcomputer U5 is connected to the input end of the first signal amplification circuit and the second signal amplification circuit, the PWM signal controller generates the first PWM signal and the second PWM signal through a software algorithm, and the duty cycle of the first PWM signal and the second PWM signal can be set by the software of the single-chip microcomputer U5. The first signal amplification circuit is implemented by an operational amplifier, the output end G1 of the operational amplifier is connected to the AC pre-stage circuit, and the first signal amplification circuit amplifies the weak signal output by the PWM signal controller to meet the input requirements of the AC pre-stage circuit. The second signal amplification circuit is the same as the first signal amplification circuit, and is implemented by an operational amplifier, the output end G2 of the operational amplifier is connected to the AC pre-stage circuit, and the weak signal output by the PWM signal controller is amplified to meet the input requirements of the AC pre-stage circuit; the AC pre-stage circuit is implemented by a power MOSFET circuit, and the switch tube of the AC pre-stage circuit is controlled by the PWM signal output by the PWM signal controller. When the switch tube is turned on, the current will flow through the switch tube and the primary winding of the transformer to generate a high-frequency AC voltage.

[0040] In an optional embodiment, if Figure 5-6 As shown, the inverter back-end circuit includes: a rectifier filter circuit, a pulse width modulation circuit and a feedback circuit. The rectifier filter circuit is electrically coupled to the inverter front-end circuit through a transformer, and is used to reduce the ripple of the output voltage of the inverter front-end circuit. The feedback circuit is electrically coupled to the rectifier filter circuit and the pulse width modulation circuit, and is used to sample the rectifier filter output voltage to control the pulse width modulation circuit. The pulse width modulation circuit is electrically coupled to the feedback circuit and the rectifier filter circuit, and under the control of the feedback circuit, the rectifier filter output voltage generated by the rectifier filter circuit is converted into an AC voltage that meets the requirements.

[0041] Specifically, the rectifier and filter circuit is implemented by a bridge rectifier and a filter capacitor, wherein the bridge rectifier rectifies the AC voltage output by the inverter front-stage circuit into a DC voltage, and the filter capacitor filters the rectified DC voltage to reduce the ripple. The feedback circuit is implemented by an operational amplifier and a comparator. The operational amplifier amplifies the output voltage of the rectifier and filter circuit, and the comparator compares the amplified output voltage with the reference voltage and outputs a control signal; the pulse width modulation circuit is implemented by a single-chip microcomputer U6, and the single-chip microcomputer U6 controls the switching time of the power MOSFET according to the control signal output by the feedback circuit, thereby controlling the amplitude of the output voltage of the rectifier and filter circuit.

[0042] In an optional embodiment, if Figure 3As shown, the first signal amplification circuit includes: a transistor Q4 and a transistor Q16; the base of the transistor Q4 and the base of the transistor Q16 are both connected to the key control circuit, the collector of the transistor Q4 is externally connected to a DC power supply, the emitter of the transistor Q4 and the emitter of the transistor Q16, the emitter of the transistor Q4 and the emitter of the transistor Q16 are connected to the common point and electrically coupled to the AC pre-stage circuit, and the collector of the transistor Q16 is grounded; the base of the transistor Q4 is connected to the key control circuit. When the key is pressed, the key control circuit outputs a high level signal, and the transistor Q4 is turned on.

[0043] Specifically, the base of transistor Q4 is connected to the key control circuit. When the key is pressed, the key control circuit outputs a high-level signal, transistor Q4 is turned on, and the collector of transistor Q4 is externally connected to a DC 12V power supply. When transistor Q4 is turned on, its collector voltage is 12V, the emitter of transistor Q4 is connected to the emitter of transistor Q16, and the emitter voltage of transistor Q16 is the emitter voltage of transistor Q4. The emitter of transistor Q4 is connected to the common contact of the emitter of transistor Q16 and electrically coupled to the AC pre-stage circuit, and the emitter voltage of transistor Q16 is transmitted to the AC pre-stage circuit through the common contact. The high-level signal output by the key control circuit is amplified, and the amplified signal is output to the AC pre-stage circuit.

[0044] The second signal amplifying circuit includes: a transistor Q5 and a transistor Q17; specifically, the base of the transistor Q5 and the base of the transistor Q17 are both connected to the key control circuit, the collector of the transistor Q5 is externally connected to a DC power supply, the emitter of the transistor Q5 is connected to the emitter of the transistor Q17, and the common contact of the emitter of the transistor Q5 and the emitter of the transistor Q17 is electrically coupled to the AC pre-stage circuit.

[0045] Specifically, the base of transistor Q5 is connected to the key control circuit. When the key is pressed, the key control circuit outputs a high-level signal and transistor Q5 is turned on. The collector of transistor Q5 is externally connected to a DC 12V power supply. When transistor Q5 is turned on, its collector voltage is 12V. The emitter of transistor Q5 is connected to the emitter of transistor Q17. The emitter voltage of transistor Q17 is the emitter voltage of transistor Q5. The emitter of transistor Q5 is connected to the common point of the emitter of transistor Q17 and electrically coupled to the AC pre-stage circuit. The emitter voltage of transistor Q17 is transmitted to the AC pre-stage circuit through the common point. The high-level signal output by the key control circuit is amplified, and the amplified signal is output to the AC pre-stage circuit.

[0046] In an optional embodiment, if Figure 4As shown, the AC front-stage circuit includes: a transistor Q6, a transistor Q7, and a transformer T1. The transistor Q7: the gate is electrically coupled to the first signal amplification circuit, the drain is electrically coupled to the transformer T1, and the source is grounded. The transistor Q6: the gate is electrically coupled to the second signal amplification circuit, the drain is electrically coupled to the transformer T1, and the source is grounded. The transformer T1 is electrically coupled to the inverter back-stage circuit, and is used to receive the amplified PWM signal and, under the control of the signal, convert the DC voltage provided by the DC power supply into an AC voltage to output to the inverter back-stage circuit.

[0047] Specifically, the AC front-stage circuit is implemented by a dual switch tube circuit, the gate of transistor Q7 is electrically coupled to the first signal amplifier circuit, when the first signal amplifier circuit outputs a high-level signal, transistor Q7 is turned on, and the drain of transistor Q7 is electrically coupled to transformer T1. When transistor Q7 is turned on, its drain voltage is the voltage of the DC power supply, and the source of transistor Q7 is grounded. The gate of transistor Q6 is electrically coupled to the second signal amplifier circuit, when the second signal amplifier circuit outputs a high-level signal, transistor Q6 is turned on, and the drain of transistor Q6 is electrically coupled to transformer T1. When transistor Q6 is turned on, its drain voltage is the voltage of the DC power supply, and the source of transistor Q6 is grounded. The primary winding of transformer T1 receives the voltage of the drain of transistor Q7 and the drain of Q6, and the secondary winding is connected to the inverter back-stage circuit. According to the above connection method, the AC front-stage circuit couples the PWM signals output by the first signal amplifier circuit and the second signal amplifier circuit to the primary winding of transformer T1. When transistors Q7 and Q6 are turned on, transformer T1 generates a high-frequency AC voltage and outputs it to the inverter back-stage circuit.

[0048] In an optional embodiment, if Figure 5 As shown, the rectifier filter circuit includes: a rectifier circuit and a filter circuit. Wherein: the rectifier circuit includes: a diode D3, a diode D4, a diode D5 and a diode D6. The diode D5 and the diode D4 are electrically connected to the same side of the secondary winding of the transformer T1, and the diode D3 and the diode D6 are connected to the other side of the secondary winding of the transformer T1, electrically coupled to the AC front-stage circuit, and used to rectify the AC voltage generated by the AC front-stage circuit and output a rectified signal to the filter circuit. Wherein, the cathode of the diode D3 and the cathode of the diode D5 are connected to form an output end of the rectifier circuit. The anode of the diode D4 and the anode of the diode D6 are connected to form another output end of the rectifier circuit and are grounded. The filter circuit includes: a capacitor EC3 and a resistor R1. The capacitor EC3 is connected across the two output ends of the rectifier circuit. One end of the resistor R1 is grounded, and the other end is electrically connected to the output end formed by the cathode of the diode D3 and the cathode of the diode D5. The filter circuit is used for filtering the rectified signal to output a filtered signal. The filter circuit is electrically coupled to the pulse width modulation circuit and the feedback circuit to provide a rectified and filtered output voltage.

[0049] Specifically, diode D5 and diode D4 are connected to the same side of the secondary winding of transformer T1. When the secondary winding of transformer T1 generates a positive half-cycle AC voltage, diode D5 is turned on and diode D4 is turned off. When the secondary winding of transformer T1 generates a negative half-cycle AC voltage, diode D4 is turned on and diode D5 is turned off. Diode D3 and diode D6 are connected to the other side of the secondary winding of transformer T1. When the secondary winding of transformer T1 generates a positive half-cycle AC voltage, diode D3 is turned off and diode D6 is turned on. When the secondary winding of transformer T1 generates a negative half-cycle AC voltage, diode D3 is turned on and diode D6 is turned off. The cathode of diode D3 and the cathode of diode D5 are connected to form one output end of the rectifier circuit, and the anode of diode D4 and the anode of diode D6 are connected to form another output end of the rectifier circuit and are grounded. According to the above connection method, the bridge rectifier circuit rectifies the high-frequency AC voltage generated by the secondary winding of transformer T1 into a DC voltage. Capacitor EC3 is connected across the two output terminals of the rectifier circuit, one end of resistor R1 is grounded, and the other end is electrically connected to the output terminal formed by the cathode of diode D3 and the cathode of diode D5. According to the above connection mode, the capacitor filter filters the DC voltage generated by the rectifier circuit to reduce ripple.

[0050] In an optional embodiment, if Figure 6 As shown, the feedback circuit includes a control integrated circuit U6. The control integrated circuit U6 is electrically coupled to the rectifier and filter circuit to receive the rectifier and filter signal; and is electrically coupled to the pulse width modulation circuit to control the pulse width modulation circuit to generate the required frequency and waveform according to the rectifier and filter signal.

[0051] Specifically, the control integrated circuit U6 compares the output voltage of the rectifier filter circuit and outputs a control signal, and the pulse width modulation circuit controls the switching time of the switch tube according to the control signal, thereby controlling the amplitude and frequency of the AC voltage output by the inverter. Preferably, the control integrated circuit U6 can use a general operational amplifier, such as LM358, which is not limited here.

[0052] In an optional embodiment, if Figure 6 As shown, the feedback circuit also includes a power supply circuit, which is used to provide a stable power supply to the control integrated circuit U6.

[0053] Specifically, the power supply circuit includes a transformer T1, a rectifier bridge U2, a three-terminal regulator U3 and a three-terminal regulator U4; wherein the transformer T1 is electrically coupled to the rectifier bridge U2, and the rectifier bridge U2 converts the control signal into a gate voltage for driving the MOS and provides a gate drive current so that the MOS can switch quickly. The three-terminal regulator U3 is electrically coupled to the rectifier bridge U2, stabilizes the DC voltage to 12V, which is used to drive the MOS, provide a stable power supply voltage for the MOS, and improve the switching performance of the MOS. The three-terminal regulator U4 is electrically coupled to the three-terminal regulator U3, which is used to stabilize the DC voltage to 5V, which is used to provide a stable power supply voltage for the control integrated circuit U6, and improve the stability and reliability of the control integrated circuit U6.

[0054] In an optional embodiment, if Figure 6 As shown, the control integrated circuit includes: a temperature detection circuit, a frequency selection circuit, a voltage detection circuit, an output current detection circuit and a fan control circuit.

[0055] Specifically, the control integrated circuit U6 divides the voltage detection resistor R52 and the resistor R54 to detect the VBUS voltage; the control integrated circuit U6 detects the resistor R55, the resistor R56, and the resistor R41 to detect the output current; the control integrated circuit U6 connects the resistor R53 and the thermistor NTC1 to detect the transformer temperature; the resistor R43 and the resistor R46 can be used to select and set the output frequency, wherein R43=10K / R16=NC output 50HZ, R43=NC / R16=10K output 60HZ, and when the output power is detected to be greater than 30W, the control integrated circuit U6 connects the resistor R34 and the transformer U1 to transmit the control signal to the transistor Q3, and the transistor Q3 controls the speed of the fan FAN1 and provides power. After the control integrated circuit detects that each indicator is normal, it outputs the AC power that meets the requirements.

[0056] Preferably, in order to achieve a better implementation effect of the circuit, the present application also uses the following components:

[0057] like Figure 2 As shown, the key control circuit further includes a capacitor C1, a capacitor C11, a transistor Q2, a resistor R11, a resistor R14, and a resistor R15.

[0058] like Figure 3 As shown, the PWM signal controller, the first signal amplifying circuit and the second signal amplifying circuit also include capacitors C6, C7, C8, C9, C10, C12, C13, C14, C15, C16, C17, and resistors R8, R9, R10, R12, R13, R16, R17, R21, R22, R23, R24, R48, R49, R50.

[0059] like Figure 4As shown, the AC front-stage circuit also includes capacitors C2, C3, C18, C19, EC1, resistors R25, R26, R28, R29, R30, R31, R32, R33, diodes D10 and D9.

[0060] like Figure 5 As shown, the rectifier and filter circuit and the pulse width modulation circuit also include capacitors C4, C5, C25, resistors R3, R4, R5, R6, R7, R37, R38, R39, R40, R41, R42, R44, R45, R46, R47, diodes D7, D8, D9, D11, D12, Zener diodes ZD2, ZD3, and transistors Q8, Q9, Q10, Q11, Q12, Q13, Q14, Q15.

[0061] like Figure 6 As shown, the feedback circuit also includes capacitors C21, C22, C23, C26, C27, C28, C31, C32, C33, C34, C35, C36, EC2, EC4, EC5, resistors R16, R18, R19, R20, R27, R34, R36, R43, R51, R52, R53, R54, R55, R56, Zener diodes ZD1, ZD4, and diode D2.

[0062] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0063] Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0064] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0065] It should also be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this specification refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when a specific feature, structure or characteristic is described in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of this application.

[0066] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0067] It should also be noted that the above are only preferred embodiments of the present application, and the patent protection scope of the present application is not limited thereto. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A portable vehicle inverter, characterized in that: include: Key control circuit, inverter front-stage circuit, inverter back-stage circuit; The key control circuit is used to electrically couple the inverter front-stage circuit to control the on-off of the inverter front-stage circuit; The inverter front-stage circuit electrically couples the DC power supply and the inverter rear-stage circuit, and is used to generate a first PWM signal and a second PWM signal, and to generate a high-frequency AC voltage by controlling the first PWM signal and the second PWM signal; The inverter rear-stage circuit is electrically coupled to the inverter front-stage circuit via a transformer, and is used to convert the high-frequency AC voltage generated by the inverter front-stage circuit into an AC voltage that meets the requirements.

2. The portable vehicle inverter according to claim 1, characterized in that: The inverter front-stage circuit comprises: A PWM signal controller, electrically coupled to the key control circuit, for generating a first PWM signal and a second PWM signal; A first signal amplifying circuit, electrically coupled to the PWM signal controller, for amplifying the first PWM signal; a second signal amplifying circuit, electrically coupled to the PWM signal controller, for amplifying the second PWM signal; An AC pre-stage circuit electrically coupling a DC power supply, the first signal amplifying circuit and the second signal amplifying circuit; Wherein, under the control of the amplified first PWM signal and the amplified second PWM signal, the AC front-stage circuit converts the DC voltage provided by the DC power supply into an AC voltage to output to the inverter rear-stage circuit.

3. The portable vehicle inverter according to claim 1, characterized in that: The inverter back-end circuit includes: a rectifier filter circuit, a pulse width modulation circuit and a feedback circuit; The rectifier filter circuit is electrically coupled to the inverter front-stage circuit through a transformer to reduce the ripple of the output voltage of the inverter front-stage circuit; The feedback circuit electrically couples the rectifying and filtering circuit and the pulse width modulation circuit, and is used to sample the rectifying and filtering output voltage to control the pulse width modulation circuit; The pulse width modulation circuit, the electrically coupled feedback circuit and the rectifying and filtering circuit, under the control of the feedback circuit, convert the rectifying and filtering output voltage generated by the rectifying and filtering circuit into an AC voltage that meets the requirements.

4. The portable vehicle inverter according to claim 2, characterized in that: The first signal amplifying circuit is used to generate the amplified first PWM signal and output it to the AC front-stage circuit; the first signal amplifying circuit includes: a transistor Q4 and a transistor Q16; the base of the transistor Q4 and the base of the transistor Q16 are both connected to the key control circuit, the collector of the transistor Q4 is externally connected to a DC power supply, the emitter of the transistor Q4 and the emitter of the transistor Q16, the emitter of the transistor Q4 and the emitter of the transistor Q16 are connected to a common point and electrically coupled to the AC front-stage circuit, and the collector of the transistor Q16 is grounded; The second signal amplifying circuit is used to generate the amplified second PWM signal and output it to the AC pre-stage circuit; the second signal amplifying circuit includes: a transistor Q5 and a transistor Q17, the base of the transistor Q5 and the base of the transistor Q17 are both connected to the key control circuit, the collector of the transistor Q5 is externally connected to a DC power supply, the emitter of the transistor Q5 is connected to the emitter of the transistor Q17, the common contact of the emitter of the transistor Q5 and the emitter of the transistor Q17 is electrically coupled to the AC pre-stage circuit, and the collector of the transistor Q17 is grounded.

5. The portable vehicle inverter according to claim 2, characterized in that: The AC front stage circuit includes: transistor Q6, transistor Q7, transformer T1; The transistor Q7: the gate is electrically coupled to the first signal amplifying circuit, the drain is electrically coupled to the transformer T1, and the source is grounded; The transistor Q6: the gate is electrically coupled to the second signal amplifying circuit, the drain is electrically coupled to the transformer T1, and the source is grounded; The transformer T1 is electrically coupled to the inverter post-stage circuit, and is used to receive the amplified PWM signal and, under the control of the signal, convert the DC voltage provided by the DC power supply into an AC voltage for output to the inverter post-stage circuit.

6. The portable vehicle inverter according to claim 3, characterized in that: The rectifying and filtering circuit comprises: a rectifying circuit and a filtering circuit, wherein: The rectifier circuit includes: a diode D3, a diode D4, a diode D5 and a diode D6, wherein the diode D5 and the diode D4 are electrically connected to the same side of the secondary winding of the transformer T1, and the diode D3 and the diode D6 are connected to the other side of the secondary winding of the transformer T1, and are electrically coupled to the AC front-stage circuit, and are used to rectify the AC voltage generated by the AC front-stage circuit and output a rectified signal to the filter circuit; wherein the cathode of the diode D3 and the cathode of the diode D5 are connected to form an output end of the rectifier circuit, and the anode of the diode D4 and the anode of the diode D6 are connected to form another output end of the rectifier circuit and are grounded, The filtering circuit includes: a capacitor EC3 and a resistor R1; the capacitor EC3 is connected across the two output ends of the rectifier circuit; one end of the resistor R1 is grounded, and the other end is electrically connected to the output end formed by the cathode of the diode D3 and the cathode of the diode D5; the filtering circuit is used to filter the rectified signal to output a filtered signal, and the filtering circuit is electrically coupled to the pulse width modulation circuit and the feedback circuit to provide a rectified and filtered output voltage.

7. The portable vehicle inverter according to claim 3, characterized in that: The feedback circuit includes a control integrated circuit; The control integrated circuit is electrically coupled to the rectifier and filter circuit to receive a rectifier and filter signal; and is electrically coupled to the pulse width modulation circuit to control the pulse width modulation circuit to generate a desired frequency and waveform according to the rectifier and filter signal.

8. The portable vehicle inverter according to claim 3, characterized in that: The feedback circuit also includes a power supply circuit, which is used to supply power to the control integrated circuit.

9. The portable vehicle inverter according to claim 7, characterized in that: The control integrated circuit comprises: a temperature detection circuit, a frequency selection circuit, a voltage detection circuit, an output current detection circuit and a fan control circuit.

Images