Multipath switching DC power supply circuit

Abstract

The utility model discloses a multipath switching DC power supply circuit, which comprises a single-chip microcomputer U82, a selection circuit and a rectification unit a, a current detection circuit comprises an optical coupler U83, a diode D101, a diode D102 and an NPN tube Q2, a power supply unit is connected between an input end Paa and an input end Pbb of a DC power supply, the current detection circuit is connected with the single-chip microcomputer U82, and the single-chip microcomputer U82 is connected with the selection circuit. The selection circuit comprises an analog quantity switch U1, a capacitor C1, a capacitor C2, a capacitor C3 and a capacitor C4, second ends of the four capacitors are respectively connected to four input ends of the analog quantity switch U1, an output end of the analog quantity switch U1 is used as an output end of the selection circuit, a control end of the analog quantity switch U1 is connected to four IO ports of the single-chip microcomputer U82 through a resistor R10, a resistor R11 and a resistor R12 respectively, and the single-chip microcomputer U82 is connected with the four IO ports of the single-chip microcomputer U82. And an electric signal output by the selection circuit is rectified by the rectification unit a and filtered by the filter capacitor C8, and then is transmitted to the output end Pcc of the direct-current power supply. The utility model has the characteristics of capacitive load characteristic, no need of external capacitor, low application cost and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to a power supply circuit especially relates to a multi-path switching DC power supply circuit. BACKGROUND

[0002] In prior art, for some power supply with inductive load characteristics, these loads will absorb certain power grid energy under the influence of load characteristics, and power factor will be reduced under long-term working condition, in order to ensure that power factor meets application standard, external capacitor can be used to compensate power, these external capacitors are generally independent equipment, cost is high, and more space is occupied. CONTENT OF UTILITY MODEL

[0003] The utility model provides a multi-path switching DC power supply circuit with capacitive load characteristics, without external capacitor and low application cost, aiming at the deficiency of prior art.

[0004] The utility model adopts the following technical scheme.

[0005] The application relates to a multi-path switching direct current power supply circuit, which comprises a single-chip microcomputer U82, a selection circuit and a rectifying unit a, and a current detection circuit comprising a photocoupler U83, a diode D101, a diode D102 and an NPN tube Q2; the anode of the diode D101 is connected to the output end Pdd of a direct current power supply, the cathode of the diode D101 is connected to the anode of the diode D102 through a resistor R17, the cathode of the diode D102 is connected to the negative output end of the first rectifying unit a, the anode of the diode D101 is also connected to the anode of the control end of the photocoupler U83 through a resistor R15, the cathode of the control end of the photocoupler U83 is connected to the collector of the NPN tube Q2, the base of the NPN tube Q2 is connected to the cathode of the diode D101 through a resistor R16, the emitter of the NPN tube Q2 is connected to the cathode of the diode D102, the input end of the photocoupler U83 is connected to the positive output end of a power supply unit through a resistor R14, the input end of the photocoupler U83 is also connected to the IO port PC1 of the single-chip microcomputer U82, the output end of the photocoupler U83 is connected to the negative output end of the power supply unit, the power supply unit is connected between the input end Paa and the input end Pbb of the direct current power supply, the current detection circuit is connected to the single-chip microcomputer U82, the selection circuit comprises an analog switch U1, capacitors C1, C2, C3 and C4, the first ends of the four capacitors are connected to each other and then connected to the input end Paa of the direct current power supply, the four capacitors are respectively connected in parallel with resistors R1, R2, R3 and R4, the second ends of the four capacitors are respectively connected to the four-way input end of the analog switch U1, the output end of the analog switch U1 serves as the output end of the selection circuit, the control end of the analog switch U1 is connected to the four IO ports of the single-chip microcomputer U82 through resistors R10, R11 and R12 respectively, the input end of the rectifying unit a is connected to the output end of the selection circuit, and a filter capacitor C8 is further connected between the positive output end and the negative output end of the rectifying unit a; the electric signal output by the selection circuit is rectified by the rectifying unit a and filtered by the filter capacitor C8, and then transmitted to the output end Pcc of the direct current power supply.

[0006] Preferably, the power supply unit comprises a rectifying unit b, an NPN tube Q79, a voltage stabilizing tube D66 and a voltage stabilizing tube D46; one input end of the rectifying unit b is connected to the input end Paa of the direct current power supply through the resistor R93 and the capacitor C5 connected in parallel with each other, the other input end of the rectifying unit b is connected to the input end Pbb of the direct current power supply, the positive output end of the rectifying unit b is connected to the cathode of the voltage stabilizing tube D66, the anode of the voltage stabilizing tube D66 is connected to the negative output end of the rectifying unit b, the voltage stabilizing tube D66 is connected in parallel with the capacitor C6 and the cathode of the voltage stabilizing tube D66 is connected to the collector of the NPN tube Q79, the emitter of the NPN tube Q79 serves as the positive output end of the power supply unit, the resistor R33 is connected between the base and the collector of the NPN tube Q79, the base of the NPN tube Q79 is also connected to the cathode of the voltage stabilizing tube D46, the anode of the voltage stabilizing tube D46 is connected to the negative output end of the rectifying unit b and the connecting point of the two serves as the negative output end of the power supply unit.

[0007] Preferably, the rectifying unit c is connected to the input end Paa and the input end Pbb of the direct current power supply respectively, the resistance R8 and the resistance R9 are connected in series between the two output ends of the rectifying unit c, the connection point of the resistance R8 and the resistance R9 is further connected to the control end anode of the optical coupling U84, the control end cathode of the optical coupling U84 is connected to the output end negative pole of the rectifying unit c, the input end of the optical coupling U84 is connected to the output end positive pole of the power supply unit through the resistance R7, the input end of the optical coupling U84 is further connected to the IO port PC2 of the single-chip microcomputer U82, and the output end of the optical coupling U84 is connected to the output end negative pole of the power supply unit.

[0008] When the above-mentioned multi-path switching direct current power supply circuit is powered on, the single-chip microcomputer U82 starts to work, the sampling current of the output end of the direct current power supply is obtained through the current detection circuit, then the sampling current is converted into a voltage signal, and the voltage signal is fed back to the single-chip microcomputer U82, the single-chip microcomputer U82 judges the power factor of the direct current power supply by using the voltage signal, and then outputs a control instruction to the capacitor driving circuit, the single-chip microcomputer U82 can connect one of the capacitors C1, C2, C3 and C4 to the main loop of the direct current power supply according to the required capacity of the capacitor, and then makes the load characteristic of the direct current power supply capacitive, so as to compensate the power factor of the direct current power supply and meet the standard requirement of the power factor, compared with the prior art, the application does not need external capacitors, and the application cost is effectively saved. In addition, the application can realize the switching of the capacitors by using an analog switch, compared with the mode of using an optical coupling as a switch component, the application is more compact and saves more space. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 Part of the principle of the multi-path switching direct current power supply circuit of the application Figure 1

[0010] Figure 2 Part of the principle of the multi-path switching direct current power supply circuit of the application Figure 2

[0011] Figure 3 Part of the principle of the multi-path switching direct current power supply circuit of the application Figure 3 DETAILED DESCRIPTION

[0012] The application will be described in more detail below in combination with the drawings and embodiments.

[0013] The application discloses a multi-path switching direct current power supply circuit, Figures 1 to 3 Fig. 1 is a schematic diagram of the principle of the multi-path switching direct current power supply circuit of the application, Figures 1 to 3 ​​​The p01, p02, p03, p04 and p05 in the circuit are electrical nodes. In the embodiment, the circuit includes a single-chip microcomputer U82, a selection circuit and a rectifier unit a. The current detection circuit includes a photo-coupler U83, a diode D101, a diode D102 and an NPN transistor Q2. The anode of the diode D101 is connected to the output terminal Pdd of a DC power supply. The cathode of the diode D101 is connected to the anode of the diode D102 through a resistor R17. The cathode of the diode D102 is connected to the negative output terminal of the first rectifier unit a. The anode of the diode D101 is also connected to the anode of the control terminal of the photo-coupler U83 through a resistor R15. The cathode of the control terminal of the photo-coupler U83 is connected to the collector of the NPN transistor Q2. The base of the NPN transistor Q2 is connected to the cathode of the diode D101 through a resistor R16. The emitter of the NPN transistor Q2 is connected to the cathode of the diode D102. The input terminal of the photo-coupler U83 is connected to the positive output terminal of a power supply unit through a resistor R14. The input terminal of the photo-coupler U83 is also connected to the IO port PC1 of the single-chip microcomputer U82. The output terminal of the photo-coupler U83 is connected to the negative output terminal of the power supply unit. The power supply unit is connected between the input terminal Paa and the input terminal Pbb of the DC power supply. The current detection circuit is connected to the single-chip microcomputer U82. The selection circuit includes an analog switch U1, a capacitor C1, a capacitor C2, a capacitor C3 and a capacitor C4. The first terminals of the four capacitors are connected to each other and then connected to the input terminal Paa of the DC power supply. The four capacitors are respectively connected in parallel with a resistor R1, a resistor R2, a resistor R3 and a resistor R4. The second terminals of the four capacitors are respectively connected to the four input terminals of the analog switch U1. The output terminal of the analog switch U1 serves as the output terminal of the selection circuit. The control terminals of the analog switch U1 are respectively connected to the four IO ports of the single-chip microcomputer U82 through a resistor R10, a resistor R11 and a resistor R12. The input terminal of the rectifier unit a is connected to the output terminal of the selection circuit. A filter capacitor C8 is further connected between the positive output terminal and the negative output terminal of the rectifier unit a. The electrical signal output by the selection circuit is rectified by the rectifier unit a and filtered by the filter capacitor C8, and then transmitted to the output terminal Pcc of the DC power supply.

[0014] In the above circuit, the rectifier unit a is composed of a diode D1, a diode D2, a diode D3 and a diode D4.

[0015] The above-mentioned circuit, after power-on, the single-chip microcomputer U82 starts to work, obtains the sampling current of the output end of the direct current power supply through the current detection circuit, then converts into a voltage signal, and feeds back to the single-chip microcomputer U82, the single-chip microcomputer U82 utilizes the voltage signal to judge the power factor of the direct current power supply, and then outputs a control instruction to the capacitor driving circuit, the single-chip microcomputer U82 can access the capacitor capacity according to the requirement, access one of the capacitor C1, the capacitor C2, the capacitor C3 and the capacitor C4 to the main loop of the direct current power supply, and then make the load characteristic of the direct current power supply capacitive, so as to compensate the power factor of the direct current power supply, meet the standard requirement of the power factor, compared with the prior art, the utility model discloses a need for external capacitor, effectively save the application cost.

[0016] As a preferred mode, see Figure 2 The power supply unit comprises a rectifier unit b, an NPN tube Q79, a stabilizing tube D66 and a stabilizing tube D46, one input end of the rectifier unit b is connected to the input end Paa of the direct current power supply through the parallel connection of the resistor R93 and the capacitor C5, the other input end is connected to the input end Pbb of the direct current power supply, the output end positive pole of the rectifier unit b is connected to the cathode of the stabilizing tube D66, the anode of the stabilizing tube D66 is connected to the output end negative pole of the rectifier unit b, the stabilizing tube D66 is connected in parallel with the capacitor C6 and the cathode thereof is connected to the collector of the NPN tube Q79, the emitter of the NPN tube Q79 serves as the output end positive pole of the power supply unit, the resistor R33 is connected between the base and the collector of the NPN tube Q79, the base of the NPN tube Q79 is also connected to the cathode of the stabilizing tube D46, the anode of the stabilizing tube D46 is connected to the output end negative pole of the rectifier unit b and the connecting point of the two serves as the output end negative pole of the power supply unit. In the above-mentioned circuit, the rectifier unit b is composed of the diode D9, the diode D10, the diode D11 and the diode D12.

[0017] Further, the embodiment comprises a rectifier unit c, two input ends of the rectifier unit c are connected to the input end Paa and the input end Pbb of the direct current power supply respectively, two output ends of the rectifier unit c are connected with the resistor R8 and the resistor R9 connected in series, the connecting point of the resistor R8 and the resistor R9 is also connected to the control end anode of an optical coupler U84, the control end cathode of the optical coupler U84 is connected to the output end negative pole of the rectifier unit c, the input end of the optical coupler U84 is connected to the output end positive pole of the power supply unit through the resistor R7, the input end of the optical coupler U84 is also connected to the IO port PC2 of the single-chip microcomputer U82, and the output end of the optical coupler U84 is connected to the output end negative pole of the power supply unit. The rectifier unit c is composed of the diode D5, the diode D6, the diode D7 and the diode D8.

[0018] In the working process of the embodiment, the power supply unit can output a direct current voltage because the power supply unit is connected between the input end Paa and the input end Paa of the direct current power supply. The current detection circuit 11 is connected to the single-chip microcomputer U82, can collect the current of the power supply output end, and feeds back the current voltage to the single-chip microcomputer U82 after current voltage conversion, so as to read the current value by the single-chip microcomputer U82. The selection circuit includes an analog switch U1, and the front ends of four capacitors are connected to each other as a node, which is connected to the input end Paa. In order to ensure reliable operation of the circuit, each capacitor is connected in parallel with a resistor, i.e. the resistor R1, the resistor R2, the resistor R3 and the resistor R4. The rear ends of the four capacitors are connected to the four input ends of the analog switch U1 respectively. The output end of the analog switch U1 serves as the output end of the selection circuit 10. The control end of the analog switch U1 is connected to the four IO ports of the single-chip microcomputer U82 through the resistor R10, the resistor R11 and the resistor R12 respectively. The output voltage of the selection circuit is transmitted to the output end Pcc after rectification by the rectification unit a, and is used to supply power to the power consumption equipment through the output end Pcc. In the embodiment, the single-chip microcomputer U82 is not limited to an AVR, a PIC single-chip microcomputer and the like.

[0019] In actual application, the output end Pcc and the output end Pdd are directly connected to the power consumption equipment. After the circuit is powered on, the NPN tube Q2 is turned on, the current of the output end Pdd passes through the resistor R15, the control end of the optical coupler U83 and the NPN tube Q2 to form a path. When the current changes, the conduction angle of the photosensitive device on the sensing end of the optical coupler U83 changes. At this time, the voltage value returned to the single-chip microcomputer U82 represents the change of the current strength, so as to complete the sampling work of the direct current power supply output current, and the voltage representing the sampling current is output to the single-chip microcomputer.

[0020] Based on the above-mentioned circuit, the utility model discloses compared with prior art without external capacitor, effectively save the application cost. In addition, the utility model discloses a analog switch can realize the switching of capacitor, compared with the mode of using optical coupler as switch component, the utility model discloses more compact, more save space.

[0021] The basic principle and main features of the utility model and the advantages of the utility model are shown and described above. Those skilled in the art should understand that the utility model is not limited to the above-mentioned embodiments, and the above-mentioned embodiments and descriptions in the specification are only to illustrate the principle of the utility model. Without departing from the spirit and scope of the utility model, various changes and improvements can be made to the utility model, and these changes and improvements all fall within the scope of the utility model claimed. The scope of protection of the utility model is defined by the appended claims and their equivalents.

Claims

1. A multi-channel switching DC power supply circuit, characterized in that: The current detection circuit comprises a photocoupler U83, a diode D101, a diode D102 and an NPN tube Q2. The anode of the diode D101 is connected to the output terminal Pdd of the direct current power supply, the cathode thereof is connected to the anode of the diode D102 through a resistor R17, the cathode of the diode D102 is connected to the negative output terminal of the first rectifier unit a, the anode of the diode D101 is also connected to the anode of the control terminal of the photocoupler U83 through a resistor R15, the cathode of the control terminal of the photocoupler U83 is connected to the collector of the NPN tube Q2, the base of the NPN tube Q2 is connected to the cathode of the diode D101 through a resistor R16, the emitter of the NPN tube Q2 is connected to the cathode of the diode D102, the input terminal of the photocoupler U83 is connected to the positive output terminal of the power supply unit through a resistor R14, the input terminal of the photocoupler U83 is also connected to the IO port PC1 of the single-chip microcomputer U82, the output terminal of the photocoupler U83 is connected to the negative output terminal of the power supply unit, the power supply unit is connected between the input terminal Paa and the input terminal Pbb of the direct current power supply, the current detection circuit is connected to the single-chip microcomputer U82, the selection circuit comprises an analog switch U1, capacitors C1, C2, C3 and C4, the first ends of the four capacitors are connected to each other and then to the input terminal Paa of the direct current power supply, the four capacitors are respectively connected in parallel with resistors R1, R2, R3 and R4, the second ends of the four capacitors are respectively connected to the four input terminals of the analog switch U1, the output terminal of the analog switch U1 serves as the output terminal of the selection circuit, the control terminal of the analog switch U1 is connected to the four IO ports of the single-chip microcomputer U82 through resistors R10, R11 and R12 respectively, the input terminal of the rectifier unit a is connected to the output terminal of the selection circuit, a filter capacitor C8 is further connected between the positive output terminal and the negative output terminal of the rectifier unit a, the electrical signal output by the selection circuit is rectified by the rectifier unit a and filtered by the filter capacitor C8, and then transmitted to the output terminal Pcc of the direct current power supply.

2. The multiple switching DC power supply circuit of claim 1, wherein, The power supply unit comprises a rectifier unit b, an NPN tube Q79, a voltage stabilizing tube D66 and a voltage stabilizing tube D46, one input terminal of the rectifier unit b is connected to the input terminal Paa of the direct current power supply through the resistor R93 and the capacitor C5 connected in parallel, the other input terminal thereof is connected to the input terminal Pbb of the direct current power supply, the positive output terminal of the rectifier unit b is connected to the cathode of the voltage stabilizing tube D66, the anode of the voltage stabilizing tube D66 is connected to the negative output terminal of the rectifier unit b, the voltage stabilizing tube D66 is connected in parallel with the capacitor C6 and the cathode thereof is connected to the collector of the NPN tube Q79, the emitter of the NPN tube Q79 serves as the positive output terminal of the power supply unit, the resistor R33 is connected between the base and the collector of the NPN tube Q79, the base of the NPN tube Q79 is also connected to the cathode of the voltage stabilizing tube D46, the anode of the voltage stabilizing tube D46 is connected to the negative output terminal of the rectifier unit b and the connecting point thereof serves as the negative output terminal of the power supply unit.

3. The multiple switching DC power supply circuit of claim 1, wherein, The rectifying unit c has two input terminals connected to the input terminals Paa and Pbb of the direct current power supply, and two output terminals between which are connected in series the resistor R8 and the resistor R9, the connection point of the resistor R8 and the resistor R9 being further connected to the control terminal anode of the optical coupler U84, the control terminal cathode of the optical coupler U84 being connected to the output terminal negative pole of the rectifying unit c, the input terminal of the optical coupler U84 being connected to the output terminal positive pole of the power supply unit through the resistor R7, the input terminal of the optical coupler U84 being further connected to the IO port PC2 of the single-chip microcomputer U82, and the output terminal of the optical coupler U84 being connected to the output terminal negative pole of the power supply unit.

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