Switching power supply topological structure

Abstract

The utility model discloses a topological structure of a switching power supply. The surge protection network is connected to commercial power and used for discharging surge current in a circuit, the input filter circuit is used for filtering interference components in a commercial power grid, and the input rectification circuit is used for converting filtered 220V commercial power into stable high-voltage direct current. The half-bridge DCDC conversion circuit is used for outputting the stable high-voltage direct current as pulsating low-voltage alternating current; the output full-wave rectification circuit is used for converting the pulsating low-voltage alternating current subjected to half-bridge conversion into pulsating low-voltage direct current; the LC output filter circuit is used for further filtering the pulsating direct current and outputting stable direct current required by a post-stage; and the output protection circuit is used for protecting the circuit. The utility model has the advantages of high working efficiency, low requirements on component parameters, low price, and input and output electrical isolation, and avoids safety risks.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of switching power supply, more particularly to a switching power supply topology structure. BACKGROUND

[0002] At present, power module generally adopts linear regulation voltage stabilizing structure, voltage adjustment module is equivalent to an adjustable resistor when working, a large amount of heat is generated when current flows through voltage adjustment module, loss is high, efficiency is low, required component parameter requirement is higher, price is expensive, and input and output are not electrically isolated, there is great security risk.

[0003] The traditional linear voltage stabilizing power supply is composed of voltage adjustment module, voltage reference module, sampling module and error comparison module. The sampling module compares the sampling value with the reference voltage by sampling the output voltage, and the comparison result is processed by the error comparison module to control the conduction degree of the adjustment voltage module, so that the output voltage remains stable. When the input-output voltage difference is large and the output current is large, there will be obvious heating and burning phenomenon at the adjustment tube, the working efficiency is low, and the input and output are not electrically isolated, which has safety risk. SUMMARY

[0004] The technical problem to be solved by the utility model is to provide a switching power supply topology structure, which electrically isolates the input and output to avoid security risks.

[0005] To solve the above technical problems, the technical scheme adopted by the utility model is as follows.

[0006] A switching power supply topology structure, comprising a surge protection network connected to the mains for discharging surge current in the circuit, an input filter circuit for filtering interference components in the mains network, an input rectifier circuit for converting the filtered 220V mains into stable high voltage DC, a half-bridge DCDC conversion circuit for outputting stable high voltage DC into pulsating low voltage AC, an output full-wave rectifier circuit for converting the pulsating low voltage AC converted by the half-bridge into pulsating low voltage DC, an LC output filter circuit for further filtering the output of the pulsating DC to obtain the required stable DC, and an output protection circuit for protecting the circuit, the input end of the surge protection network is connected to the mains, the output end of the surge protection network is connected to the input end of the input filter circuit, the output end of the input filter circuit is connected to the input end of the input rectifier circuit, the output end of the input rectifier circuit is connected to the input end of the half-bridge DCDC conversion circuit, the output end of the half-bridge DCDC conversion circuit is connected to the input end of the output full-wave rectifier circuit, the output end of the output full-wave rectifier circuit is connected to the input end of the LC output filter circuit, and the output end of the LC output filter circuit is connected to the input end of the output protection circuit.

[0007] Further optimization technical scheme, the surge protection network includes the pressure sensitive resistance and gas discharge tube connected in series after connecting between the commercial power and the ground terminal for discharging the surge current in the circuit.

[0008] Further optimization technical scheme, the input filter circuit includes the differential mode inductance and X capacitor connected in series on the output terminal of the pressure sensitive resistance for filtering the differential mode interference in the circuit, and the common mode inductance and Y capacitor for filtering the common mode interference in the circuit, the common mode inductance is connected in series between the differential mode inductance and the X capacitor, and the Y capacitor is arranged between the output terminal of the X capacitor and the ground terminal.

[0009] Further optimization technical scheme, the input rectifier circuit includes the current limiting resistance connected in series on the output terminal of the Y capacitor for limiting the current, the rectifier bridge for converting the pulsating high-voltage alternating current into pulsating high-voltage direct current, and the filter capacitor for converting the pulsating high-voltage direct current into smooth high-voltage direct current.

[0010] Further optimization technical scheme, the half-bridge DCDC conversion circuit includes the half-bridge DCDC capacitor connected in series on the output terminal of the filter capacitor for providing a path for the circuit, the direct current isolation capacitor for isolating the direct current component in the circuit, the high-frequency transformer for realizing the input and output electrical isolation, and the MOS tube for realizing the on-off of the circuit, the primary of the high-frequency transformer is connected with the MOS tube, and the secondary of the high-frequency transformer is connected with the input terminal of the output full-wave rectifier circuit.

[0011] Further optimization technical scheme, the output full-wave rectifier circuit includes the rectifier diode connected in series on the secondary of the high-frequency transformer for converting the pulsating low-voltage alternating current within 12A into pulsating low-voltage direct current, and the RC peak absorber for absorbing the peak voltage generated at both ends of the rectifier diode.

[0012] Further optimization technical scheme, the LC output filter circuit includes the LC filter circuit connected in series on the output terminal of the rectifier diode for outputting the pulsating low-voltage direct current within 10A as smooth direct current.

[0013] Further optimization technical scheme, the output protection circuit includes the Y capacitor connected between the output terminal of the LC filter circuit and the ground terminal for suppressing the common mode interference, and the pressure sensitive resistance and gas discharge tube connected in series between the output terminal of the LC filter circuit and the ground terminal.

[0014] Thanks to the above technical scheme, the technical progress achieved by the utility model is as follows.

[0015] The switch power supply topology provided by the utility model is composed of input filter, rectifier, half-bridge DCDC conversion, output full-wave rectification and output filter circuit, has high working efficiency, low requirement on the parameters of components and devices, low price, and realizes input and output electrical isolation, thereby avoiding safety risks. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the topological structure of this utility model;

[0017] Figure 2 This is a structural block diagram of the surge protection network of this utility model;

[0018] Figure 3 This is a structural block diagram of the input filter circuit of this utility model;

[0019] Figure 4 This is a structural block diagram of the input rectifier circuit of this utility model;

[0020] Figure 5 This is a block diagram of the half-bridge DC-DC converter circuit of this utility model;

[0021] Figure 6 This is a block diagram of the output full-wave rectifier circuit of this utility model;

[0022] Figure 7 This is a block diagram of the LC output filter circuit of this utility model;

[0023] Figure 8 This is a structural block diagram of the output protection circuit of this utility model. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0025] A switching power supply topology, combined with Figure 1As shown, including surge protection network, input filter circuit, input rectifier circuit, half-bridge DCDC conversion circuit, output full-wave rectifier circuit, LC output filter circuit and output protection circuit. Surge protection network is connected to the mains to discharge the surge current in the circuit, the input filter circuit is used to filter out the interference components in the power grid, the input rectifier circuit is used to convert the filtered 220V mains into stable high voltage DC, the half-bridge DCDC conversion circuit is used to output the stable high voltage DC into pulsating low voltage AC, the output full-wave rectifier circuit is used to convert the pulsating low voltage AC output by the half-bridge into pulsating low voltage DC, the LC output filter circuit is used to further filter the pulsating DC output to obtain the required stable DC in the later stage, and the output protection circuit is used to protect the circuit. The input end of the surge protection network is connected to the mains, the output end of the surge protection network is connected to the input end of the input filter circuit, the output end of the input filter circuit is connected to the input end of the input rectifier circuit, the output end of the input rectifier circuit is connected to the input end of the half-bridge DCDC conversion circuit, the output end of the half-bridge DCDC conversion circuit is connected to the input end of the output full-wave rectifier circuit, the output end of the output full-wave rectifier circuit is connected to the input end of the LC output filter circuit, and the output end of the LC output filter circuit is connected to the input end of the output protection circuit.

[0026] The structural block diagram of the surge protection network is as shown in Figure 2 The structural block diagram of the surge protection network is as shown in

[0027] The structural block diagram of the input filter circuit is as shown in Figure 3 The structural block diagram of the input filter circuit is as shown in

[0028] The structural block diagram of the input rectifier circuit is as shown in Figure 4 The structural block diagram of the input rectifier circuit is as shown in

[0029] The structural block diagram of the half-bridge DCDC conversion circuit is as shown in Figure 5As shown, including the half-bridge DCDC capacitor connected in series in the output end of the filter capacitor, DC blocking capacitor, high-frequency transformer and MOS tube, the half-bridge DCDC capacitor provides a path for the circuit; the DC blocking capacitor isolates the DC component in the circuit; the high-frequency transformer realizes input-output electrical isolation; the MOS tube is switched at high speed to realize the on-off of the circuit, and the circuit can work within 160W.

[0030] The structural block diagram of the output full-wave rectifier circuit is as shown in Figure 6 As shown, including the rectifier diode and RC peak absorption circuit connected in series after being connected in parallel on the secondary side of the high-frequency transformer, the high-frequency transformer realizes input-output electrical isolation; the rectifier diode converts the pulsed low-voltage alternating current within 12A into pulsed low-voltage direct current; and the RC peak absorption circuit absorbs the peak voltage generated across the rectifier diode.

[0031] The structural block diagram of the LC output filter circuit is as shown in Figure 7 As shown, including the LC filter circuit connected in series on the output end of the rectifier diode, which is used to output the pulsed low-voltage direct current within 10A as smooth direct current.

[0032] The structural block diagram of the output protection circuit is as shown in Figure 8 As shown, including the Y capacitor connected between the output end of the LC filter circuit and the ground end, and the pressure-sensitive resistor and gas discharge tube connected in series between the output end of the LC filter circuit and the ground end, the Y capacitor is used to suppress common-mode interference, and the pressure-sensitive resistor and gas discharge tube are used to discharge the inrush current in the circuit to protect the power supply module, and the pressure-sensitive resistor and gas discharge tube can discharge 10KA inrush current.

[0033] The mains L and N enter the surge protection network, which can discharge the inrush current in the circuit to protect the subsequent circuit, and the alternating current after passing through the surge protection network enters the input filter circuit, which converts the mains into clean and stable alternating current, the alternating current enters the current limiting circuit to prevent excessive current during initial power-on, and the relay is attracted after a period of time to bypass the current limiting circuit, the alternating current after passing through the input rectifier circuit becomes smooth high-voltage direct current, the high-voltage direct current is output through the half-bridge DCDC conversion circuit to generate pulsed low-voltage alternating current, and input-output electrical isolation is realized, the pulsed low-voltage alternating current is converted into pulsed low-voltage direct current through the output full-wave rectifier circuit, the peak absorption circuit prevents the voltage across the output rectifier diode from being too high, and finally the LC output filter circuit and the anti-reverse diode are used to convert the output into smooth direct current, and Y capacitor filtering and surge protection network are added to the output part for surge protection.

Claims

1. A switching power supply topology, characterized in that: The circuit includes a surge protection network connected to the mains power supply to discharge surge current in the circuit; an input filter circuit to filter out interference components in the mains power grid; an input rectifier circuit to convert the filtered 220V mains power into stable high-voltage DC power; a half-bridge DC-DC converter circuit to output stable high-voltage DC power as pulsating low-voltage AC power; an output full-wave rectifier circuit to convert the pulsating low-voltage AC power after the half-bridge converter into pulsating low-voltage DC power; an LC output filter circuit to further filter the pulsating DC power and output the stable DC power required by the subsequent stage; and an output protection circuit to protect the circuit. The input terminal of the surge protection network is connected to the mains power supply, the output terminal of the surge protection network is connected to the input terminal of the input filter circuit, the output terminal of the input filter circuit is connected to the input terminal of the input rectifier circuit, the output terminal of the input rectifier circuit is connected to the input terminal of the half-bridge DC-DC converter circuit, the output terminal of the half-bridge DC-DC converter circuit is connected to the input terminal of the output full-wave rectifier circuit, the output terminal of the output full-wave rectifier circuit is connected to the input terminal of the LC output filter circuit, and the output terminal of the LC output filter circuit is connected to the input terminal of the output protection circuit.

2. The switching power supply topology according to claim 1, characterized in that: The surge protection network includes a varistor and a gas discharge tube connected in series between the mains power and the grounding terminal to discharge surge current in the circuit.

3. The switching power supply topology according to claim 2, characterized in that: The input filtering circuit includes a differential-mode inductor and an X capacitor connected in series at the output terminal of the varistor to filter out differential-mode interference in the circuit, and a common-mode inductor and a Y capacitor connected in series between the differential-mode inductor and the X capacitor to filter out common-mode interference in the circuit. The common-mode inductor is connected in series between the differential-mode inductor and the X capacitor, and the Y capacitor is located between the output terminal of the X capacitor and the ground terminal.

4. The switching power supply topology according to claim 3, characterized in that: The input rectifier circuit includes a current-limiting resistor connected in series with the output terminal of the Y capacitor to limit the current, a rectifier bridge to convert pulsating high-voltage AC to pulsating high-voltage DC, and a filter capacitor to convert pulsating high-voltage DC to smooth high-voltage DC.

5. A switching power supply topology according to claim 4, characterized in that: The half-bridge DC-DC converter circuit includes a half-bridge DC-DC capacitor connected in series at the output terminal of the filter capacitor to provide a path for the circuit, a DC blocking capacitor to isolate the DC component in the circuit, a high-frequency transformer to achieve electrical isolation between input and output, and a MOSFET to achieve circuit switching. The primary winding of the high-frequency transformer is connected to the MOSFET, and the secondary winding of the high-frequency transformer is connected to the input terminal of the output full-wave rectifier circuit.

6. The switching power supply topology according to claim 5, characterized in that: The output full-wave rectifier circuit includes a rectifier diode connected in parallel and then in series on the secondary side of the high-frequency transformer to convert pulsating low-voltage AC power up to 12A into pulsating low-voltage DC power, and an RC spike absorber for absorbing the spike voltage generated across the rectifier diode.

7. A switching power supply topology according to claim 6, characterized in that: The LC output filter circuit includes an LC filter circuit connected in series with the output terminal of the rectifier diode to output pulsating low-voltage DC power of less than 10A as stable DC power.

8. A switching power supply topology according to claim 7, characterized in that: The output protection circuit includes a Y capacitor connected between the output terminal of the LC filter circuit and the ground terminal to suppress common-mode interference, and a varistor and a gas discharge tube connected in series between the output terminal of the LC filter circuit and the ground terminal.

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