CN201490899U

CN201490899U - DC power supply circuit

Info

Publication number: CN201490899U
Application number: CN2009201618010U
Authority: CN
Inventors: 徐建华
Original assignee: Shenzhen Lvsun Electronic Technology Co ltd
Current assignee: Shenzhen Lvsun Electronic Technology Co ltd
Priority date: 2009-06-24
Filing date: 2009-06-24
Publication date: 2010-05-26
Anticipated expiration: 2019-06-24

Abstract

The utility model relates to a DC power supply circuit which is provided with two power supply circuits, wherein a power supply circuit 1 is a universal AC circuit AC-DC part, and a power supply circuit 2 is a universal DC power supply circuit DC-DC part; the power supply circuit 2 is formed by adding a DC/DC step-up and step-down switching control circuit on a universal AC circuit, so that the working efficiency of the DC power supply circuit can be improved; and simultaneously, two power supply circuits share a power conversion circuit, and at least one transformer is omitted, so that the volume and the cost are reduced. The DC power supply circuit simply and effectively solves the problems of low efficiency, large heat emission, large volume and high cost of the existing DC power supply.

Description

DC power supply circuit

Technical field

The utility model relates to a kind of DC power supply circuit, a kind of DC power supply circuit of saying so more specifically.

Background technology

At present, in needing the electronic application of stabilized supply voltage, as present existing circuit, DC power supply circuit is divided into two kinds to DC power supply circuit usually by widely: one is the AC-DC DC power supply circuit, and another kind of is the DC-DC DC power supply circuit.

Wherein the DC-DC DC power supply circuit is divided into two kinds usually again: one is connected the main coil of transformer and the series circuit of switch between an end of DC power supply and the other end, transformer secondary output coil place connects rectifier smoothing circuit and the regression equation DC-DC DC transfer circuit of local resonance with capacitor that be connected in parallel at the switch place, transformer energy storage during switch connection, transformer released energy to load-side when switch disconnected, when local resonance has electric charge with capacitor is residual when switch connection, because this electric charge discharges through switch, can produce power consumption, so this circuit efficiency is not high and used transformer and volume is bigger; Another kind of DC-DC DC power supply circuit is by the conducting of PWM pulse width modulation mode control switch pipe with by realizing purpose to control big inductive energy storage and to discharge electric energy; rely on the mode of an inductive energy storage and release electric energy fully; in the time of in whole input voltage range and the output voltage range; take into account less than the efficient of being had a few all for the highest; thereby make power-efficient low; the inductance caloric value is big; influence life of product; the mode that relies on simultaneously a switch controlled inductive energy storage fully and release energy, then overvoltage; overcurrent; protective circuits such as excess temperature implement more complicated.

Usually the AC-DC DC power supply circuit uses one or more transformers to come changing voltage, as 200620024426.1 combined type AC/DC supply units, at least two transformers have just been used, the circuit normal conditions that AC-DC DC power supply circuit and DC-DC DC power supply circuit are merged are used two or more transformers at least so, thereby volume is bigger, and cost is also very high.

Summary of the invention

For overcoming above-mentioned deficiency, the utility model provides a kind of DC power supply circuit.

To achieve these goals, the technical solution adopted in the utility model is: a kind of DC power supply circuit, it comprises power circuit 1 and power circuit 2, power circuit 1 is general alternating current circuit AC-DC part, power circuit 2 is general DC circuit DC-DC part, it is characterized in that power circuit 1 and power circuit 2 shared circuit for power conversion, simultaneously, power circuit 2 has increased a DC/DC buck conversion control circuit that changes to move with output voltage on general DC circuit.

Preferably, the power circuit 1 of described DC power supply circuit and power circuit 2 have specifically comprised AC input filter rectifier, the DC input filter circuit, AC/DC PWM and power control circuit, DC/DC PWM and power control circuit, circuit for power conversion, voltage stabilizing feedback circuit and output rectifier and filter; AC input filter rectifier input connects the AC input signal of DC power supply circuit, the circuit for power conversion two ends connect AC input filter rectifier and output rectifier and filter respectively, AC/DC PWM and power control circuit are connected across between AC input filter rectifier and the circuit for power conversion, DC input filter circuit input connects the DC input signal of DC power supply circuit, DC/DCPWM and power control circuit are connected across between DC input filter circuit and the circuit for power conversion, the voltage stabilizing feedback circuit connects DC OUTPUT end and the AC/DC PWM and the power control circuit of DC power supply circuit, and the voltage stabilizing feedback circuit also is connected with DC/DC PWM and power control circuit.

Preferably, a DC/DC buck of cross-over connection conversion control circuit between the DC OUTPUT end of described circuit for power conversion and DC power supply circuit, cross-over connection the one MOSFET Q17 between the input ground of its circuit for power conversion and the output ground of output rectifier and filter, cross-over connection the 2nd MOSFET Q18 between the output ground of output rectifier and filter and the input anode of circuit for power conversion, the grid of described first and second MOSFET is electrically connected on DC/DC buck change-over circuit respectively.

Preferably, operational amplifier U7, diode: D17, D18, D21, D22, D23, D24, D25, resistance: R77, R78, R79, R80, R94, R95, MOSFET Q20 and MOSFET Q21 form DC/DC buck conversion control circuit.

When operational amplifier U7 detected input voltage less than output voltage, MOSFET Q20 will conducting, and MOSFET Q21 ends immediately, thereby MOSFET Q18 conducting, MOSFET Q17 are ended, and the ground of output and the ground of input are connected, and realized boost function; When operational amplifier U7 detects input voltage greater than output voltage, will allow MOSFET Q21 conducting, MOSFET Q20 end, thereby MOSFET Q17 conducting, MOSFET Q18 are ended, make the ground of output and the just connection of input, realize buck functionality; Therefore, the utility model is to decide according to the relation between input and the output voltage to boost or step-down, fully equivalent BOOST circuit of the utility model circuit when boosting, give the output power supply after being equivalent to inductance and input string and getting up again, at this moment utilized a part of input, thereby the inductance burden is alleviated, and one one of output current is provided by input simultaneously, thereby power-efficient is got a promotion;

Regulate output owing to utilize input and inductance to act on simultaneously, the energy that consumes on inductance so reduces, and the problem that the power supply caloric value is big also is improved.

Because the utility model has added DC/DC buck conversion control circuit and a MOSFET Q17 coefficient with it, the 2nd MOSFET Q18; when the utility model adds protective circuit so; feedback signal not only makes the control chip U8 of power circuit 2 remove to close MOSFET Q19 by feedback and finishes the purpose that stops power work, simultaneously a MOSFET Q17, the 2nd MOSFET Q18 is closed and reach the purpose that stops power work fast

Because power circuit 1 (general alternating current circuit AC-DC part) and the shared circuit for power conversion of power circuit 2 (general DC circuit DC-DC part) in the utility model, only need an inductance just can achieve the goal, therefore, reduced at least one transformer.

Therefore; the utility model not only can improve the efficient of whole input voltage range and output voltage range when direct current is imported; the problem that the power supply caloric value is big also can improve; and having reduced by a transformer by the mode of the shared power transfer of AC-DC Circuit part, protections such as overvoltage simultaneously, overcurrent, short circuit are more prone to realization.

Description of drawings

Fig. 1 is a theory structure schematic diagram of the present utility model;

Fig. 2 is a circuit unit structured flowchart of the present utility model;

Fig. 3 is DC input filter circuit figure of the present utility model;

Fig. 4 is AC input filter rectifier figure of the present utility model;

Fig. 5 is AC/DC PWM of the present utility model and power control circuit and AC/DC input switching part circuit diagram.

Fig. 6 is circuit for power conversion of the present utility model, output rectifier and filter and voltage stabilizing feedback circuit figure.

Fig. 7 is DC/DC buck conversion control circuit figure of the present utility model.

Fig. 8 is DC/DC PWM of the present utility model and power control circuit figure.

Embodiment

Below in conjunction with drawings and the specific embodiments the utility model will be further described explanation.

As shown in Figure 1, the utility model discloses a kind of DC power supply circuit, it comprises power circuit 1 and power circuit 2, power circuit 1 is general alternating current circuit AC-DC part, power circuit 2 is general DC circuit DC-DC part, and power circuit 2 has increased a DC/DC buck conversion control circuit that changes to move with output voltage on general DC circuit.

As shown in Figure 2, the utility model DC power supply circuit has specifically comprised AC input filter rectifier, the DC input filter circuit, AC/DC PWM and power control circuit, DC/DC PWM and power control circuit, circuit for power conversion, voltage stabilizing feedback circuit, protective circuit, DC/DC buck conversion control circuit and output rectifier and filter; AC input filter rectifier input connects the AC input signal of DC power supply circuit, the circuit for power conversion two ends connect AC input filter rectifier and output rectifier and filter respectively, AC/DC PWM and power control circuit are connected across between AC input filter rectifier and the circuit for power conversion, DC input filter circuit input connects the DC input signal of DC power supply circuit, DC/DC PWM and power control circuit are connected across between DC input filter circuit and the circuit for power conversion, the voltage stabilizing feedback circuit connects DC OUTPUT end and the AC/DC PWM and the power control circuit of DC power supply circuit, and the voltage stabilizing feedback circuit also is connected with DC/DC PWM and power control circuit.

As shown in Figure 2, DC/DC buck conversion control circuit is connected across between the DC OUTPUT end of circuit for power conversion and DC power supply circuit.

As shown in Figure 2, protective circuit is electrically connected with AC/DC PWM and power control circuit, DC/DC PWM and power control circuit and voltage stabilizing feedback circuit respectively.

As shown in Figure 3, inductance L 4, diode D27, electric capacity: C30, C31, C32, C33 form the DC input filter circuit jointly, smoothly filter the noise of DC input signal.

As shown in Figure 4, by fuse F1, inductance: LF1, LF2, rectifier bridge: BD1, electric capacity: C1, C2, CX1, CY1, CY2 and other elements constitute AC input filter rectifier, and the AC input signal is carried out filtering and rectification.

As Fig. 5, shown in Figure 6, by chip: U1, U4, U5, U6, MOSFET:Q1, Q14, Q15, Q16, inductance: T1, L5 and peripheral circuit thereof are formed the AC TO DC main circuit part of DC power supply circuit.

As Fig. 6, Fig. 7, shown in Figure 8, by chip: U2, U4, U7, U8, MOSFET:Q15, Q16, Q17, Q18, Q19, inductance: T1, L3 and peripheral circuit thereof form buck DC TO DC main circuit part.

As shown in Figure 6, chip: U1, U2, U4, inductance: T1, L2, LF3, MOSFET:Q2, Q3, Q11, Q15, Q16, Q17, Q18 and peripheral circuit thereof form the main circuit part of power transfer, voltage stabilizing feedback, protection and output filtering.

As Fig. 5, Fig. 7, shown in Figure 8, by chip: U3, U6, U7, U8, MOSFET:Q10, Q12, Q13 and peripheral circuit thereof are formed AC input and DC input conversion main circuit part.

As shown in Figure 7, DC/DC buck conversion control circuit comprises: operational amplifier U7, diode: D17, D18, D21, D24, D25, resistance: R 77, R78, R79, R80, R94, R95, MOSFET:Q20, Q21; Operational amplifier U7 the 4th pin ground connection, the 2nd pin of operational amplifier U7 and the 5th pin are electrically connected on the OUTPUT positive pole of DC power supply circuit, the DC reference voltage that the 3rd pin of operational amplifier U7 and the 6th pin are electrically connected on DC power supply circuit is (negative pole of diode D12 in the DC/DC buck conversion control circuit) just, the 8th pin of operational amplifier U7 is electrically connected on the negative pole of diode D25, the 7th pin of operational amplifier U7 is connected with the negative electricity of diode D18, the 1st pin of operational amplifier U7 is connected with the negative electricity of diode D24, the positive pole of diode D18 is electrically connected with the grid of MOSFET Q20, the positive pole of diode D24 is electrically connected with the grid of MOSFET Q21, the drain electrode of MOSFET Q20 and MOSFETQ21 is ground connection all, the negative pole of diode D17 is electrically connected with the drain electrode of MOSFETQ20, the positive pole of diode D17 is electrically connected with the grid of MOSFET Q17, the negative pole of diode D21 is electrically connected with the drain electrode of MOSFET Q21, the positive pole of diode D21 is electrically connected with the grid of MOSFETQ18, the two ends of resistance R 77 are electrically connected with the 8th pin of MOSFET Q21 drain electrode and operational amplifier U7 respectively, the two ends of resistance R 78 are electrically connected with the 8th pin of MOSFET Q21 grid and operational amplifier U7 respectively, the two ends of resistance R 79 are electrically connected with the 8th pin of MOSFET Q20 drain electrode and operational amplifier U7 respectively, the two ends of resistance R 80 are electrically connected with the 8th pin of MOSFET Q20 grid and operational amplifier U7 respectively, the two ends of resistance R 94 respectively with MOSFET Q21 grid and be electrically connected, the two ends of resistance R 95 respectively with MOSFET Q20 grid and be electrically connected, the negative pole of diode D25 is electrically connected with the 8th pin of operational amplifier U7, and the positive pole of diode D25 is electrically connected with the 7th pin VCC of chip U8.

As Fig. 7, the positive pole of diode D23 is electrically connected with the grid of MOSFET Q20, the negative pole of diode D23 is electrically connected with the drain electrode of MOSFET Q21, and the positive pole of diode D22 is electrically connected with the grid of MOSFET Q21, and the negative pole of diode D22 is electrically connected with the drain electrode of MOSFET Q20.

As shown in Figure 7, the 2nd, 5 pin of operational amplifier U7 are electrically connected, and the 3rd, 6 pin of operational amplifier U 3 are electrically connected.

After the utility model DC power supply circuit is connected the AC input, AC input filter rectifier carries out rectifying and wave-filtering to input, chip U6 energising will be worked, at this moment chip U6 output PFC VCC voltage is given chip U5 power supply, chip U5 work, while chip U6, chip U5 exports high level, MOSFET Q14, MOSFET Q1 conducting, the PFC of DC power supply circuit and PWM are open-minded, inductance L 5 and all energy storage of T1, when output voltage that reaches designing requirement and power, chip U6, chip U5 output low level, MOSFETQ14 and MOSFET Q1 are turned off, the PFC output of boosting, inductance T1 is by MOSFET Q15, MOSFET Q1, MOSFET Q17 powering load is simultaneously to the output capacitance charging, and so periodic duty reaches the stable purpose of exporting.

When the output voltage of the utility model DC power supply circuit has downward trend, chip U6 and chip U5 will receive the feedback signal of voltage stabilizing feedback circuit, its duty ratio is increased, and inductive energy storage increases, and output voltage increases, when its output voltage is on the rise, chip U6 and chip U5 will receive the feedback signal of voltage stabilizing feedback circuit, and its duty ratio is reduced, and inductive energy storage reduces, output voltage decreases, thereby reaches the purpose of stable output.

When the utility model DC power supply circuit is connected the DC input, the DC input filter circuit smoothly filters the noise of input signal, simultaneously, the chip U8 work of will switching on, chip U8 exports high level, MOSFET Q19 conducting thereupon, inductance T1 energy storage, when inductive current rises to cut-off level, chip U8 output low level, MOSFET Q19 ends thereupon, at this moment inductance T1 is by MOSFETQ16, MOSFET Q15, MOSFET Q17, MOSFET Q18 powering load charges to output capacitance simultaneously, when output reached designing requirement voltage, chip U8 exported high level once more, and MOSFETQ19 is conducting once more, so circulation is to reach the purpose of stable output; Voltage stabilizing is by U4, and U2 and U8 realize.

When output voltage had downward trend, chip U4 and peripheral circuit thereof fed back to chip U8 after error is amplified, and its duty ratio is increased, and inductive energy storage increases, and reaches the purpose of voltage stabilizing;

When output voltage had downward trend, chip U4 and peripheral circuit thereof fed back to chip U8 after error is amplified, and its duty ratio is reduced, and inductive energy storage reduces, and reaches the purpose of voltage stabilizing;

When operational amplifier U7 detected input voltage less than output voltage, MOSFET Q20 will conducting, and MOSFET Q21 ends immediately, thereby MOSFET Q18 conducting, MOSFET Q17 are ended, and the ground of output and the ground of input are connected, and realized boost function; When operational amplifier U3 detects input voltage greater than output voltage, will allow MOSFET Q21 conducting, MOSFET Q20 end, thereby MOSFET Q17 conducting, MOSFET Q18 are ended, make the ground of output and the just connection of input, realize buck functionality;

Because the 2nd, 5 pin of operational amplifier U7 are electrically connected in the DC/DC buck conversion control circuit, the 3rd, 6 pin of operational amplifier U7 are electrically connected, then the output signal of the pin 1 of operational amplifier U7 and pin 7 is opposite, then make MOSFET Q20, MOSFET Q21 conducting simultaneously, the situation of conducting simultaneously can not appear in MOSFET Q17 and MOSFET Q18 yet so, avoids unusual generation.

When AC imports, MOSFET Q10 conducting, optocoupler U's 3 will conducting so, thereby make MOSFET Q12, MOSFET Q13 end, therefore chip U8, chip U7 do not have the VCC operating voltage, so the DC part will be closed by force when AC imports, thereby avoid unusual generation.

When overvoltage, overcurrent, excess temperature, overload occurring, chip U4 etc. and peripheral circuit thereof will be exported triggering signal and draw dead MOSFET Q1 or MOSFET Q19 and peripheral circuit by chip U5, U6 or U8, to reach the purpose of protection.

Above-described only is the utility model DC power supply circuit preferred implementation; should be pointed out that for the person of ordinary skill of the art, under the prerequisite that does not break away from the utility model creation design; can also make some distortion and improvement, these all belong to protection range of the present utility model.

Claims

1. DC power supply circuit, it comprises general alternating current circuit AC-DC part-power circuit 1 and general DC circuit DC-DC part-power circuit 2, it is characterized in that described power circuit 1 and power circuit 2 shared circuit for power conversion, described power circuit 2 has increased a DC/DC buck conversion control circuit that changes to move with output voltage on general DC circuit DC-DC part basis.

2. DC power supply circuit according to claim 1, it is characterized in that described power circuit 1 and power circuit 2 have specifically comprised AC input filter rectifier, the DC input filter circuit, AC/DCPWM and power control circuit, DC/DC PWM and power control circuit, circuit for power conversion, voltage stabilizing feedback circuit and output rectifier and filter; AC input filter rectifier input connects the AC input signal of DC power supply circuit, the circuit for power conversion two ends connect AC input filter rectifier and output rectifier and filter respectively, AC/DC PWM and power control circuit are connected across between AC input filter rectifier and the circuit for power conversion, the DC input filter circuit is electrically connected with the DC input of DC power supply circuit, DC/DC PWM and power control circuit are connected across between DC input filter circuit and the circuit for power conversion, the voltage stabilizing feedback circuit is electrically connected DC OUTPUT end and the AC/DC PWM and the power control circuit of DC power supply circuit, and the voltage stabilizing feedback circuit also is electrically connected with DC/DC PWM and power control circuit.

3. DC power supply circuit according to claim 2, it is characterized in that a DC/DC buck of cross-over connection conversion control circuit between the DC OUTPUT end of described circuit for power conversion and DC power supply circuit, cross-over connection the one MOSFET Q17 between the input ground of described circuit for power conversion and the output ground of output rectifier and filter, cross-over connection the 2nd MOSFET Q18 between the output ground of output rectifier and filter and the input anode of circuit for power conversion, the grid of described first and second MOSFET is electrically connected on DC/DC buck conversion control circuit respectively.

4. DC power supply circuit according to claim 2 is characterized in that described AC/DC PWM and power control circuit, DC/DC PWM and power control circuit and voltage stabilizing feedback circuit are electrically connected the protective circuit of DC power supply circuit respectively.

5. DC power supply circuit according to claim 3, it is characterized in that described DC/DC buck conversion control circuit comprises operational amplifier U7, diode: D17, D18, D21, D24, D25, resistance: R77, R78, R79, R80, R94, R95, MOSFET:Q20, Q21; Operational amplifier U7 the 4th pin ground connection, the 2nd pin of operational amplifier U7 and the 5th pin are electrically connected on the OUTPUT positive pole of DC power supply circuit, the 3rd pin of operational amplifier U7 and the 6th pin are electrically connected on the DC reference voltage positive pole (negative pole of diode D12 in the DC/DC buck conversion control circuit) of DC power supply circuit, the 8th pin of operational amplifier U7 is electrically connected on the negative pole of diode D25, the 7th pin of operational amplifier U7 is connected with the negative electricity of diode D18, the 1st pin of operational amplifier U7 is connected with the negative electricity of diode D24, the positive pole of diode D18 is electrically connected with the grid of MOSFET Q20, the positive pole of diode D24 is electrically connected with the grid of MOSFET Q21, the drain electrode of MOSFET Q20 and MOSFETQ21 is ground connection all, the negative pole of diode D17 is electrically connected with the drain electrode of MOSFET Q20, the positive pole of diode D17 is electrically connected with the grid of MOSFET Q17, the negative pole of diode D21 is electrically connected with the drain electrode of MOSFET Q21, the positive pole of diode D21 is electrically connected with the grid of MOSFET Q18, the two ends of resistance R 77 are electrically connected with the 8th pin of MOSFET Q21 drain electrode and operational amplifier U7 respectively, the two ends of resistance R 78 are electrically connected with the 8th pin of MOSFET Q21 grid and operational amplifier U7 respectively, the two ends of resistance R 79 are electrically connected with the 8th pin of MOSFET Q20 drain electrode and operational amplifier U7 respectively, the two ends of resistance R 80 are electrically connected with the 8th pin of MOSFET Q20 grid and operational amplifier U7 respectively, the two ends of resistance R 94 respectively with MOSFET Q21 grid and be electrically connected, the two ends of resistance R 95 respectively with MOSFET Q20 grid and be electrically connected, the negative pole of diode D25 is electrically connected with the 8th pin of operational amplifier U7, and the positive pole of diode D25 is electrically connected with the 7th pin VCC of chip U8.

6. DC power supply circuit according to claim 4 is characterized in that described protective circuit comprises chip U1, chip U2, and chip U3 and chip U4 and peripheral circuit thereof are formed various protective circuits, realize overcurrent, overvoltage, excess temperature, short-circuit protection function.

7. DC power supply circuit according to claim 5, the positive pole that it is characterized in that diode D23 is electrically connected with the grid of MOSFET Q20, the negative pole of diode D23 is electrically connected with the drain electrode of MOSFET Q21, the positive pole of diode D22 is electrically connected with the grid of MOSFET Q21, and the negative pole of diode D22 is electrically connected with the drain electrode of MOSFET Q20.

8. DC power supply circuit according to claim 5 is characterized in that the 2nd, 5 pin of operational amplifier U7 are electrically connected, and the 3rd, 6 pin of operational amplifier U3 are electrically connected.

9. DC power supply circuit according to claim 5 is characterized in that chip U3, U6, U7, U8, and MOSFET:Q10, Q12, Q13 and peripheral circuit thereof are formed AC input and DC input change-over circuit part.