CN114553045A - Inverter power supply for EL cold light sheet - Google Patents
Inverter power supply for EL cold light sheet Download PDFInfo
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- CN114553045A CN114553045A CN202210272752.8A CN202210272752A CN114553045A CN 114553045 A CN114553045 A CN 114553045A CN 202210272752 A CN202210272752 A CN 202210272752A CN 114553045 A CN114553045 A CN 114553045A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/53—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M7/537—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters
- H02M7/5387—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
- H02M1/088—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters for the simultaneous control of series or parallel connected semiconductor devices
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/44—Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
- H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
- H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/33569—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements
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- Inverter Devices (AREA)
Abstract
The invention discloses an inverter power supply of an EL cold light sheet, which comprises an alternating current input circuit, an EMI anti-interference circuit, a primary rectifying and filtering circuit, an MOS power circuit, a PWM control circuit, a booster circuit, a first rectifying and filtering circuit, a half-bridge inverter circuit and a control module. The half-bridge topological structure enables the transformer to be magnetized in two directions, the iron core can be utilized efficiently, and the working frequency is high; and the power device is in a switch state, so that the size of the transformer can be reduced, and the size of the whole power supply is reduced. Meanwhile, the frequency of the switching tube is 1/2 of the output PWM wave frequency, which is beneficial to reducing the pulsation of the output DC bus voltage and improving the voltage stabilization precision; alternating current output voltage, output current and frequency generated by the half-bridge inverter circuit change and are fed back to the control module through the feedback circuit, the control module generates different PWM signals according to the feedback signal to control a switching tube in the half-bridge inverter circuit, automatic adjustment of the output voltage, the output current and the frequency is achieved, and the intelligent degree is high.
Description
Technical Field
The invention belongs to the technical field of inverter power supplies, and particularly relates to an inverter power supply of an EL cold light sheet.
Background
The EL electroluminescent sheet is a new high-tech light source, and can produce various electroluminescent sheet products with bright colors. The solar energy collector can fully convert electric energy into light energy, has excellent characteristics, and is widely applied to the fields of advertisement industry, automobile industry, electronic product liquid crystal backlight, building exterior walls, interior decoration and the like.
The existing EL cold light sheet driving inverter power supply usually adopts a power frequency transformer, the power frequency transformer is wound by using an iron core, so that the size and the weight are large, the transportation is not facilitated, the manufacturing cost is high, and the peak value duration is short, the efficiency is low and the stability is poor due to low working frequency. And the control of the output frequency and the output voltage adopts an adjustable resistor, and the adjustable resistor is rotated by hands to control. Is very inconvenient and not intelligent enough.
Disclosure of Invention
The invention provides an inverter power supply for an EL (electroluminescent) cold light sheet, which solves the problems that the driving inverter power supply for the EL cold light sheet in the prior art has large volume and weight, low power supply conversion efficiency and low working frequency; and the adjustable resistor is manually rotated to control the output frequency and the output voltage, which is very inconvenient.
In order to solve the technical problems, the invention adopts the following technical scheme:
an inverter power supply of an EL cold light sheet comprises an alternating current input circuit, a booster circuit, a first rectification filter circuit, a half-bridge inverter circuit, an alternating current filter circuit, an alternating current output circuit and a control module; the alternating current input circuit, the booster circuit, the first rectifying and filtering circuit, the half-bridge inverter circuit, the alternating current filtering circuit and the alternating current output circuit are electrically connected in sequence; the control module is respectively connected with the alternating current output circuit and the half-bridge inverter circuit;
the alternating current input circuit is connected with external 220V and 50HZ alternating currents, the booster circuit boosts the 220V and 50HZ alternating currents, the first rectifying and filtering circuit rectifies and filters the boosted alternating currents and then outputs first direct currents, the first alternating currents are output through the half-bridge inverter circuit and output through the alternating current output circuit after passing through the alternating current filtering circuit, required voltage, current and frequency are obtained, and power is supplied to the EL cold light piece.
The control module generates a first PWM signal according to the collected current and voltage signals output by the alternating current output circuit to drive a switching tube in the half-bridge inverter circuit.
The existing inversion power supply of the EL cold light sheet adopts a power frequency transformer, works in a linear region, and the power tube is always in an open state, so that the efficiency is lower. According to the switching power supply of the input voltage commercial power, the main circuit adopts a half-bridge topological structure, so that the transformer is magnetized in two directions, an iron core can be utilized efficiently, and the working frequency is high; and the power device is in a switch state, so that the size of the transformer can be reduced, and the size of the whole power supply is reduced. Meanwhile, the frequency of the switching tube is 1/2 of the output PWM wave frequency, which is beneficial to reducing the pulsation of the output DC bus voltage, reducing the size of the filter inductor and improving the voltage stabilization precision; the primary side circuit of the transformer has a simple structure and is beneficial to improving the utilization rate of input voltage.
According to the invention, the alternating current output voltage, the output current and the frequency generated by the half-bridge inverter circuit are changed and fed back to the control module through the feedback circuit, the control module generates different PWM signals according to the feedback signal to control a switch tube in the half-bridge inverter circuit, and the purpose of regulating the output voltage, the output current and the frequency is achieved. Through setting up control module, adjust automatically, intelligent degree is high, and is very convenient.
Further optimizing, the system also comprises an EMI anti-interference circuit, a primary rectifying and filtering circuit, an MOS power circuit and a PWM control circuit; the alternating current input circuit, the EMI anti-interference circuit, the primary rectifying and filtering circuit, the MOS power circuit and the booster circuit are sequentially connected through circuits, and the PWM control circuit is electrically connected with the first rectifying and filtering circuit and the MOS power circuit respectively.
The EMI anti-interference circuit performs anti-electromagnetic interference treatment on externally accessed 220V and 50HZ alternating current, the primary rectification filter circuit performs filtering and rectification on the alternating current subjected to the anti-interference treatment, primary direct current is output, the primary direct current is inverted through the MOS power circuit and then outputs primary alternating current, and the primary alternating current is boosted through the booster circuit; the PWM control circuit generates a primary PWM signal with fixed frequency to drive an MOS tube in the MOS power circuit.
In the invention, the EMI anti-interference circuit is arranged, so that the interference and noise in the circuit are reduced. Through setting up elementary rectification filter circuit, MOS power circuit and PWM control circuit, improve stability, prevent to lead to the transformer impaired because of voltage fluctuation.
And further optimizing, transmitting the voltage signal output by the alternating current output circuit to the control module through the voltage feedback circuit, and transmitting the current signal output by the alternating current output circuit to the control module through the current feedback circuit. The reference voltage circuit and the reference current circuit have high precision and are similar to standard voltage and current sources.
Further optimizing, the MOS power circuit, the boost circuit and the first rectifying and filtering circuit which are connected in sequence comprise a third MOS transistor Q3, a fourth MOS transistor Q4, a boost transformer, a first rectifying diode D1, a second rectifying diode D2 and a fifth filtering capacitor C5;
the third MOS tube Q3 is connected with the third filter capacitor C3 in series, the fourth MOS tube Q4 is connected with the fourth filter capacitor C4 in series, and the third MOS tube Q3 and the fourth filter capacitor C4 are connected with the two ends of the primary side of the step-up transformer after being connected in parallel; two ends of the secondary coil T02 of the transformer are respectively connected with the anodes of the first rectifier diode D1 and the second rectifier diode D2, the center tap of the secondary coil of the transformer is the negative electrode of the output voltage, and the rectified voltage is filtered by the fifth filter capacitor C5.
The half-bridge inverter circuit comprises two bridge arms, wherein the first bridge arm consists of a first MOS (metal oxide semiconductor) tube Q1, a third fly-wheel diode D3 and a fourth fly-wheel diode D4; the second bridge arm consists of a second MOS transistor Q2, a fifth freewheeling diode D5 and a sixth freewheeling diode D6; and a joint is led out between the two bridge arm connecting points and is connected with an alternating current filter circuit.
Further optimization, the core chip of the control module is a single chip microcomputer; the output of the alternating current output circuit is divided into two paths, wherein one path is connected with a corresponding pin of the singlechip through a voltage feedback circuit; the other path is that the current feedback circuit is connected with a corresponding pin of the singlechip; the output signal of the single chip microcomputer is divided into two paths and is respectively connected with a first MOS tube Q1 and a second MOS tube Q2 which correspond to the half-bridge inverter circuit.
Further optimizing, the control chip model of the PWM control circuit is KA 7500B. The integrated circuit with adjustable pulse width and the control, modulation and protection circuit of the switching power supply are all in the integrated circuit, and the integrated circuit is widely applied to single-ended forward, half-bridge, full-bridge and push-pull switching power supplies. All pulse width modulation circuits are integrated inside the pulse width modulation circuit; the linear sawtooth oscillator is arranged in the chip, and the external part only needs one resistor and one capacitor to form an oscillation element; an error amplifier is arranged inside; the 5V reference voltage source is arranged in the chip; the dead time is adjustable; a power transistor with 400mA driving capability is arranged in a chip; has two output modes of push and pull.
Compared with the prior art, the technical scheme provided by the invention has the following beneficial effects:
1. according to the switching power supply of the input voltage commercial power, the main circuit adopts a half-bridge topological structure, so that the transformer is magnetized in two directions, an iron core can be utilized efficiently, and the working frequency is high; and the power device is in a switch state, so that the size of the transformer can be reduced, and the size of the whole power supply is reduced. Meanwhile, the frequency of the switching tube is 1/2 of the output PWM wave frequency, which is beneficial to reducing the pulsation of the output DC bus voltage, reducing the size of the filter inductor and improving the voltage stabilization precision; the primary side circuit of the transformer has a simple structure and is beneficial to improving the utilization rate of input voltage. The invention adopts the design of a high-frequency transformer, and overcomes the defects of large volume and weight of a power supply, low power conversion efficiency, difficult transportation and the like caused by adopting a power frequency transformer in the prior art.
2. According to the invention, alternating current output voltage, output current and frequency generated by the half-bridge inverter circuit are changed and fed back to the control module through the feedback circuit, the control module generates different PWM signals according to the feedback signal to control a switching tube in the half-bridge inverter circuit, and the purpose of adjusting the output voltage, the output current and the frequency is achieved. Through setting up control module, adjust automatically, intelligent degree is high, and is very convenient. The problem of adopt adjustable resistance among the prior art, manual regulation, not intelligent enough and the easy damage of component is overcome.
Drawings
FIG. 1 is a block diagram of an inverter power supply for an EL cold light sheet according to the present invention;
FIG. 2 is a voltage boosting circuit diagram of the inverter of the EL cold light sheet according to the present invention;
FIG. 3 is a diagram of a half-bridge inverter circuit of an inverter power supply for the EL cold light sheet according to the present invention;
FIG. 4 is a control module and voltage and current feedback circuit diagram of the inverter power supply of the EL cold light sheet of the present invention.
Detailed Description
For a further understanding of the disclosure of the present invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings.
As shown in fig. 1, an inverter power supply for an EL cold light sheet includes an ac input circuit, an EMI anti-interference circuit, a primary rectifying and filtering circuit, an MOS power circuit, a PWM control circuit, a boost circuit, a first rectifying and filtering circuit, a half-bridge inverter circuit, an ac filtering circuit, an ac output circuit, and a control module. The alternating current input circuit, the EMI anti-interference circuit, the primary rectifying and filtering circuit, the MOS power circuit, the booster circuit, the first rectifying and filtering circuit, the half-bridge inverter circuit, the alternating current filtering circuit and the alternating current output circuit are sequentially and electrically connected; the PWM control circuit is respectively and electrically connected with the first rectifying and filtering circuit and the MOS power circuit; the control module is respectively connected with the alternating current output circuit and the half-bridge inverter circuit.
The alternating current input circuit is used for connecting 220V and 50HZ alternating current to an EMI anti-interference circuit, and the EMI anti-interference circuit mainly plays a role in isolating interference waves which influence normal work of a power supply and exist in an alternating current input power supply and isolating high-frequency working interference signals generated by the power supply; the output of the EMI anti-interference circuit is connected to a primary rectifying and filtering circuit, and the direct current processed by the rectifying and filtering circuit is filtered by using a specific element to be changed into a smoother direct current; the primary rectifying and filtering circuit outputs primary direct current to the MOS tube power circuit, and the MOS tube power circuit converts the primary direct current into primary alternating current with periodic amplitude variation; the PWM control circuit generates a primary PWM signal with fixed frequency to drive an MOS tube in the MOS power circuit. The MOS tube power circuit is connected with a step-up transformer, and the step-up transformer boosts the variable voltage into an expected alternating voltage; the step-up transformer is connected with the first rectifying and filtering circuit and converts the periodic conversion voltage into a first direct current; then the first direct current is converted into a first alternating current with alternating voltage and frequency through a half-bridge inverter circuit, interference waves on the alternating current are filtered out completely through an alternating current filter circuit, and the alternating current is converted into variable-frequency and variable-voltage alternating current without harmonic components and then is output through an alternating current output circuit to supply power for the EL cold light sheet. The control module generates a first PWM signal according to the collected current and voltage signals output by the alternating current output circuit to drive a switching tube in the half-bridge inverter circuit.
The existing inversion power supply of the EL cold light sheet adopts a power frequency transformer, works in a linear region, and the power tube is always in an open state, so that the efficiency is lower. According to the switching power supply of the input voltage commercial power, the main circuit adopts a half-bridge topological structure, so that the transformer is magnetized in two directions, an iron core can be utilized efficiently, and the working frequency is high; and the power device is in a switch state, so that the size of the transformer can be reduced, and the size of the whole power supply is reduced. Meanwhile, the frequency of the switching tube is 1/2 of the output PWM wave frequency, which is beneficial to reducing the pulsation of the output DC bus voltage, reducing the size of the filter inductor and improving the voltage stabilization precision; the primary side circuit of the transformer has a simple structure and is beneficial to improving the utilization rate of input voltage.
According to the invention, alternating current output voltage, output current and frequency generated by the half-bridge inverter circuit are changed and fed back to the control module through the feedback circuit, the control module generates different PWM signals according to the feedback signal to control a switching tube in the half-bridge inverter circuit, and the purpose of adjusting the output voltage, the output current and the frequency is achieved. Through setting up control module, adjust automatically, intelligent degree is high, and is very convenient.
As shown in fig. 2, the MOS power circuit, the boost circuit and the first rectifying and filtering circuit, which are connected in sequence, include a third MOS transistor Q3, a fourth MOS transistor Q4, a boost transformer, a first rectifying diode D1, a second rectifying diode D2 and a fifth filtering capacitor C5.
The third MOS tube Q3 is connected with the third filter capacitor C3 in series, the fourth MOS tube Q4 is connected with the fourth filter capacitor C4 in series, and the third MOS tube Q3 and the fourth filter capacitor C4 are connected with the two ends of the primary side of the step-up transformer after being connected in parallel; two ends of the secondary coil T02 of the transformer are respectively connected with the anodes of the first rectifier diode D1 and the second rectifier diode D2, the center tap of the secondary coil of the transformer is the negative electrode of the output voltage, and the rectified voltage is filtered by the fifth filter capacitor C5.
When Q3 is turned on and Q4 is turned off, an input voltage U0 is applied to the primary winding T01, and an induced electromotive force is generated in the secondary winding T02, so that the diode D1 is turned on by receiving a positive voltage, and is filtered by C5 to supply power to a load, and at this time, the diode D2 is turned off by receiving a reverse voltage. The output voltage UOUT at this time is
Here, Uout is the output voltage, T01 is the primary coil, T02 is the secondary coil, ton is the on-time, T is the period.
When Q3 is turned off and Q4 is turned on, an input voltage U0 is applied to the primary winding T01, and an induced electromotive force is generated in the secondary winding T02, so that the diode D2 is subjected to a positive voltage to be turned on, and is filtered by C5 to supply power to a load, and at this time, the diode D1 is turned off due to a back voltage. The output voltage Uout at this time is
When both Q3 and Q4 are off, both D1 and D2 are in the on state, and each share half the current.
When Q3 is switched on and Q4 is switched off, the voltage of a primary coil is half of the power supply voltage U0, the induced electromotive forces of the upper part and the lower part of a central tap of T02 are equal, when Q3 is switched off and Q4 is switched on, the voltage of the primary coil is half of the power supply voltage U0, and the induced electromotive forces of the upper part and the lower part of the central tap of T02 are equal; if Q3 and Q4 are conducted simultaneously, which is equivalent to short circuit of the primary winding of the transformer, the duty ratio of each switching tube is not more than 50% and a certain dead time is set to avoid the short circuit.
The above is the output current continuous condition, when the output current is interrupted, the output voltage Uout will be higher than the calculated value of the above equation and increase with the decrease of the load, in the limit condition of zero load,
in this embodiment, the control chip of the PWM control circuit has a model number of KA 7500B. The integrated circuit with adjustable pulse width and the control, modulation and protection circuit of the switching power supply are all in the integrated circuit, and the integrated circuit is widely applied to single-ended forward, half-bridge, full-bridge and push-pull switching power supplies. All pulse width modulation circuits are integrated inside the pulse width modulation circuit; the linear sawtooth oscillator is arranged in the chip, and the external part only needs one resistor and one capacitor to form an oscillation element; an error amplifier is arranged inside; the 5V reference voltage source is arranged in the chip; the dead time is adjustable; a power transistor with 400mA driving capability is arranged in a chip; has two output modes of push and pull.
As shown in fig. 3, the half-bridge inverter circuit includes two legs, the first leg is composed of a first MOS transistor Q1, a third freewheeling diode D3, and a fourth freewheeling diode D4; the second bridge arm consists of a second MOS transistor Q2, a fifth freewheeling diode D5 and a sixth freewheeling diode D6; and a joint is led out between the two bridge arm connecting points and is connected with an alternating current filter circuit.
U1 is input first direct current voltage, C1 is smoothing capacitor, and C0 and L form a filter circuit. The drain of Q1 is connected with the positive pole of the power voltage, the source is connected with D4, D5, Q2, the source of Q2 is connected with one end of 1C, and in addition, the source is connected with the output filter inductor through D6. The two tubes Q1 and Q2 are alternatively conducted, and the two pairs of tubes are alternatively conducted for 180 degrees. The middle point of the two bridge arms is the output, and the circuit outputs the inductive load.
At the first moment, the switching tube Q1 is turned on, the switching tube Q2 is turned off, the output voltage is OUT, the output current is gradually increased, and the freewheeling diodes D3 and D4 are both turned off by receiving the directional voltage. At the second moment, at the beginning, Q1 is turned off, Q2 is not conducted, at this moment, the freewheeling diode D3 is turned on to freewheel the load current, and the current flows through Q1, the load and D3 to form a loop and gradually decreases; q1 is then also turned off, at which time freewheeling diode D3 turns on freewheeling and the output current is fed back to the input voltage U1 and decreases further. The current forms a loop through D4, the load, D3, and the voltage source U1. The current decreases to zero at the second instant. At the third moment, the switching tubes Q1 and Q2 are turned off, Q2 and Q1 are turned on, the output voltage is-U1, the output current gradually increases, and the freewheeling diodes D3 to D6 are all turned off by receiving the directional voltage. At the fourth moment, at the beginning, Q1 is turned off, Q2 is not turned off, at this moment, the freewheeling diode D4 is turned on, and freewheels for the load current, and the current flows through Q2, the load and D4 to form a loop and gradually decreases; q2 is then also turned off, at which time diode D1 turns on freewheeling and the output current is fed back to the input voltage U1 and decreases further. The current forms a loop through D4, the load, D5, and the voltage source U1. The current decreases to zero at the fifth time. The current change at the fifth time is the same as that at the first time. The fourth time is the start of the next switching cycle, as is the second time.
In this embodiment, the core chip of the control module is a single chip; the output of the alternating current output circuit is divided into two paths, wherein one path is connected with a corresponding pin of the singlechip through a voltage feedback circuit; the other path is that the current feedback circuit is connected with a corresponding pin of the singlechip; the output signal of the single chip microcomputer is divided into two paths and is respectively connected with a first MOS tube Q1 and a second MOS tube Q2 which correspond to the half-bridge inverter circuit.
As shown in fig. 4, the voltage feedback circuit is formed by serially connecting a resistor R5, a diode DZ1 and a transistor Q5, and is connected with the 8 th pin of the single chip microcomputer U4. The current feedback circuit consists of a resistor R6 and an optocoupler U3, and the voltage feedback circuit is connected with the 6 th pin of the singlechip U4. The single chip microcomputer control circuit is divided into two paths to be connected with the half-bridge inverter circuit, one path of the single chip microcomputer control circuit emits PWM waves, the PWM waves are connected to the optocoupler U1 through R8, and then the PWM waves are connected to Q1 through R2. The other route singlechip sends out PWM waves, which pass through R7 to U2 and then pass through R4 to Q2. The function of the circuit is to feed back the output voltage, the output current and the frequency to the singlechip control circuit when the output voltage, the output current and the frequency change, the singlechip sends out different PWM signals according to the fed back signals to control the Q1 and the Q2 to adjust the output voltage, the output current and the frequency. Through setting up control module, adjust automatically, intelligent degree is high, and is very convenient. The problem of adopt adjustable resistance among the prior art, manual regulation, not intelligent enough and the easy damage of component is overcome.
The present invention and its embodiments have been described above schematically, without limitation, and what is shown in the drawings is only one of the embodiments of the present invention, and the actual structure is not limited thereto. Therefore, if the person skilled in the art receives the teaching, without departing from the spirit of the invention, the person skilled in the art shall not inventively design the similar structural modes and embodiments to the technical solution, but shall fall within the scope of the invention.
Claims (7)
1. An inverter power supply of an EL cold light sheet is characterized by comprising an alternating current input circuit, a booster circuit, a first rectification filter circuit, a half-bridge inverter circuit, an alternating current filter circuit, an alternating current output circuit and a control module; the alternating current input circuit, the booster circuit, the first rectifying and filtering circuit, the half-bridge inverter circuit, the alternating current filtering circuit and the alternating current output circuit are electrically connected in sequence; the control module is respectively connected with the alternating current output circuit and the half-bridge inverter circuit;
the alternating current input circuit is connected with external 220V and 50HZ alternating currents, the booster circuit boosts the 220V and 50HZ alternating currents, the first rectifying and filtering circuit rectifies and filters the boosted alternating currents and then outputs first direct currents, the first alternating currents are output through the half-bridge inverter circuit and then output through the alternating current output circuit after passing through the alternating current filtering circuit, and power is supplied to the EL cold light sheet;
the control module generates a first PWM signal according to the collected current and voltage signals output by the alternating current output circuit to drive a switching tube in the half-bridge inverter circuit.
2. The inverter power supply for the EL cold light sheet as claimed in claim 1, further comprising an EMI anti-interference circuit, a primary rectifying and filtering circuit, an MOS power circuit and a PWM control circuit;
the alternating current input circuit, the EMI anti-interference circuit, the primary rectifying and filtering circuit, the MOS power circuit and the booster circuit are sequentially connected in a circuit mode, and the PWM control circuit is electrically connected with the first rectifying and filtering circuit and the MOS power circuit respectively;
the EMI anti-interference circuit performs anti-electromagnetic interference treatment on externally accessed 220V and 50HZ alternating current, the primary rectification filter circuit performs filtering and rectification on the alternating current subjected to the anti-interference treatment, primary direct current is output, the primary direct current is inverted through the MOS power circuit and then outputs primary alternating current, and the primary alternating current is boosted through the booster circuit;
the PWM control circuit generates a primary PWM signal with fixed frequency to drive an MOS tube in the MOS power circuit.
3. The inverter power supply for EL cold light sheet according to claim 2, wherein the voltage signal outputted from the ac output circuit is transmitted to the control module through the voltage feedback circuit, and the current signal outputted from the ac output circuit is transmitted to the control module through the current feedback circuit;
the control module compares a reference voltage signal generated by the reference voltage circuit with a feedback voltage signal and compares a reference current signal generated by the reference current circuit with a feedback current signal, and the PWM control chip outputs the compared PWM signal according to the comparison result to drive an MOS tube in the half-bridge inverter circuit.
4. The inverter power supply for the EL cold light sheet as claimed in claim 3, wherein the MOS power circuit, the voltage boost circuit and the first rectifying and filtering circuit, which are connected in sequence, comprise a third MOS transistor Q3, a fourth MOS transistor Q4, a voltage boost transformer, a first rectifying diode D1, a second rectifying diode D2 and a fifth filtering capacitor C5;
the third MOS tube Q3 is connected in series with the third filter capacitor C3, the fourth MOS tube Q4 is connected in series with the fourth filter capacitor C4, and the third MOS tube Q3 and the fourth filter capacitor C4 are connected in parallel and then are connected with two ends of the primary side of the step-up transformer; two ends of the secondary coil T02 of the transformer are respectively connected with the anodes of the first rectifier diode D1 and the second rectifier diode D2, the center tap of the secondary coil of the transformer is the negative electrode of the output voltage, and the rectified voltage is filtered by the fifth filter capacitor C5.
5. The inverter power supply for the EL cold light sheet as claimed in claim 4, wherein the half-bridge inverter circuit comprises two bridge arms, the first bridge arm is composed of a first MOS transistor Q1, a third freewheeling diode D3 and a fourth freewheeling diode D4; the second bridge arm consists of a second MOS transistor Q2, a fifth freewheeling diode D5 and a sixth freewheeling diode D6; and a joint is led out between the two bridge arm connecting points and is connected with an alternating current filter circuit.
6. The inverter power supply for the EL cold light sheet as claimed in claim 2, wherein the core chip of the control module is a single chip microcomputer; the output of the alternating current output circuit is divided into two paths, wherein one path is connected with a corresponding pin of the singlechip through a voltage feedback circuit; the other path is that the current feedback circuit is connected with a corresponding pin of the singlechip; the output signal of the single chip microcomputer is divided into two paths and is respectively connected with a first MOS tube Q1 and a second MOS tube Q2 which correspond to the half-bridge inverter circuit.
7. The inverter power supply for EL cold light sheet as claimed in claim 2, wherein the control chip of the PWM control circuit is KA 7500B.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202210272752.8A CN114553045A (en) | 2022-03-18 | 2022-03-18 | Inverter power supply for EL cold light sheet |
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| CN202210272752.8A CN114553045A (en) | 2022-03-18 | 2022-03-18 | Inverter power supply for EL cold light sheet |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116961380A (en) * | 2023-06-19 | 2023-10-27 | 珠海艾珂斯科技有限公司 | Control circuit and method with high-frequency inverter power supply output for X-ray machine |
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- 2022-03-18 CN CN202210272752.8A patent/CN114553045A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116961380A (en) * | 2023-06-19 | 2023-10-27 | 珠海艾珂斯科技有限公司 | Control circuit and method with high-frequency inverter power supply output for X-ray machine |
| CN116961380B (en) * | 2023-06-19 | 2024-05-03 | 珠海艾珂斯科技有限公司 | Control circuit and method with high-frequency inverter power supply output for X-ray machine |
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