Switching voltage-stabilized power supply applied to drilling tool

Abstract

The switching voltage-stabilized power supply applied to the drilling tool provided by the utility model can convert a 24V-36V voltage-stabilized power supply into + / -12V and 5V standard voltage, has the characteristics of high power and stable output, simplifies the design of a circuit system of the intelligent drilling tool and the size of a circuit board, and improves the stability of the circuit system applied to the intelligent drilling tool.

Description

Technical Field

[0001] The utility model belongs to the field of intelligent drilling equipment for petroleum and natural gas, in particular to a switching voltage-stabilized power supply applied to drilling tools. Background Art

[0002] Intelligent drilling tools are mainly used in the technical fields of bottom hole parameter measurement, deflection correction, and orientation in drilling projects. They can strengthen the monitoring of complex downhole conditions, realize wellbore trajectory control, improve drilling speed and oil and gas recovery rate, and reduce drilling costs. They have huge market demand and broad application prospects in major oilfield blocks. The realization of all functions of intelligent drilling tools requires complex circuits such as measurement and control. The power supply is the basic condition and heart of the circuit. The stability of the power supply directly affects the working performance of the circuit system, thereby determining whether the intelligent drilling tool can work normally.

[0003] In the circuit system of intelligent drilling tools, many circuits or electronic components use ±12V and 5V standard voltages to realize measurement and control functions. The overall circuit system has the characteristics of high power consumption. The integrated voltage-stabilized power supply chip power supply currently used has the characteristics of small single-chip power and cannot meet the power requirements, while the power supply of multiple integrated voltage-stabilized power supply chips makes the circuit design more complicated, increases the circuit volume, and is not conducive to the stability of the circuit system. Although lithium battery power supply has the characteristics of small ripple and stable output voltage, it has problems such as large volume, fast discharge in high temperature environment, and insufficient power supply.

[0004] Therefore, the present application contemplates a switching regulated power supply that can be applied to a vertical drilling tool. Utility Model Content

[0005] In view of the problems existing in the prior art, the utility model provides a switching voltage-stabilized power supply applied to drilling tools to solve the problems of complex circuit lines, large size and insufficient battery power supply caused by the use of voltage-stabilized power supply chips in intelligent drilling tools, while improving the stability performance of the circuit system of the intelligent drilling tool.

[0006] The utility model is realized by the following technical solutions:

[0007] A switching voltage-stabilized power supply for drilling tools comprises a voltage-stabilized power supply, wherein the output end of the voltage-stabilized power supply is connected to the input end of a power supply undervoltage protection circuit, and is respectively connected to the input end of a T1 transformer, the input end of a T2 transformer, the input end of a first power supply pulse width modulation circuit, and the input end of a second power supply pulse width modulation circuit through a reverse protection and filtering circuit; the output end of the power supply undervoltage protection circuit is connected to the input end of the first power supply pulse width modulation circuit and the input end of the second power supply pulse width modulation circuit; the output end of the primary winding of the T1 transformer is connected to the first power supply pulse width modulation circuit through a power switching device Q1; the secondary first winding of the T1 transformer is respectively connected to the input end of a first power supply error feedback circuit and the input end of a first power supply overvoltage protection circuit through a first rectifier and filter circuit; the secondary second winding of the T1 transformer is connected to the second rectifier and filter circuit; The input end of the first power supply pulse width modulation circuit is also connected to the output end of the first power supply error feedback circuit and the output end of the first power supply overvoltage protection circuit; the source of the power switch device Q1 is connected to one end of the current sampling resistor R3, and the other end of the current sampling resistor R3 is connected to the negative electrode of the voltage-stabilized power supply; the output end of the primary winding of the T2 transformer is connected to the second power supply pulse width modulation circuit through the power switch device Q2, and the secondary winding of the T2 transformer is respectively connected to the input end of the second power supply error feedback circuit and the input end of the second power supply overvoltage protection circuit through the third rectifier and filter circuit; the input end of the second power supply pulse width modulation circuit is respectively connected to the output end of the second power supply error feedback circuit and the output end of the second power supply overvoltage protection circuit; the source of the power switch device Q2 is connected to one end of the current sampling resistor R4, and the other end of the current sampling resistor R4 is connected to the negative electrode of the voltage-stabilized power supply.

[0008] Furthermore, the drain of the power switch device Q1 is connected to the output end of the primary winding of the T1 transformer, the gate is connected to the output end of the first power pulse width modulation circuit, and the source is connected to the input end of the first power pulse width modulation circuit and one end of the current sampling resistor R3;

[0009] The power switch device Q2 has a drain connected to the output end of the primary winding of the T2 transformer, a gate connected to the output end of the second power pulse width modulation circuit, and a source connected to the input end of the second power pulse width modulation circuit and one end of the current sampling resistor R4.

[0010] Furthermore, the power supply undervoltage protection circuit includes a first reference voltage circuit, a resistor R1, a resistor R2 and a comparison amplifier U1; the first reference voltage circuit adopts an LM25017 chip, the input end of the first reference voltage circuit and one end of the resistor R1 are both connected to the positive electrode of the output end of the regulated power supply, the output end of the first reference voltage circuit is connected to the negative input end of the comparison amplifier U1, the resistor R1 and the resistor R2 are connected in series and then connected to the positive and negative electrodes of the regulated power supply, the positive input end of the comparison amplifier U1 is connected to the series node of the resistor R1 and the resistor R2, and the output end is connected to the input end of the first power supply pulse width modulation circuit and the input end of the second power supply pulse width modulation circuit.

[0011] Furthermore, the reverse protection and filtering circuit includes a diode D1, an inductor L1 and a capacitor C1, the positive electrode of the diode D1 is connected to the positive electrode of the output end of the regulated power supply, the negative electrode of the diode D1 is connected to one end of the inductor L1, the other end of the inductor L1 is connected to one end of the capacitor C1 and the input end of the primary winding of the T1 transformer, and the other end of the capacitor C1 is connected to the ground of the regulated power supply.

[0012] Furthermore, the first rectifying and filtering circuit includes a diode D2, an inductor L2, a capacitor C2 and a capacitor C3, one end of the capacitor C2 and one end of the capacitor C3 are connected to the two ends of the inductor L2 respectively, and the other end of the capacitor C2 and the other end of the capacitor C3 are connected to the power supply V OUT﹢12V Ground, one end of the inductor L2 is connected to the cathode of the diode D2, and the other end of the inductor L2 is connected to the positive output terminal of the power supply V OUT﹢12V , the positive terminal of diode D2 is connected to the output end of the first secondary winding of transformer T1.

[0013] Furthermore, the second rectifying and filtering circuit includes a diode D3, an inductor L3, a capacitor C4 and a capacitor C5, one end of the capacitor C4 and one end of the capacitor C5 are respectively connected to the two ends of the inductor L3, and the other end of the capacitor C2 and the other end of the capacitor C are both connected to the power output terminal V OUT-12V , the first end of the inductor L3 is connected to the cathode end of the diode D3, and the other end of the inductor L3 is connected to the power supply V OUT-12V The anode terminal of the diode D2 is connected to the output terminal of the second secondary winding of the transformer T1.

[0014] Furthermore, the first power supply overvoltage protection circuit includes a resistor R5, a resistor R6, a second reference voltage circuit and a comparison amplifier U2, and one end of the resistor R5 is connected to the positive electrode V of the power supply output terminal. OUT﹢12V , the other end of resistor R5 is connected to one end of resistor R6, and the other end of resistor R6 is connected to the power supply V OUT﹢12V The positive input terminal of the comparison amplifier U2 and the input terminal of the second reference voltage circuit are respectively connected to the two ends of the resistor R5; the second reference voltage circuit adopts the LM2576 chip, the output terminal of the second reference voltage circuit is connected to the negative terminal of the comparison amplifier U2, and the output terminal of the comparison amplifier is connected to the ±12V first power supply pulse width modulation circuit.

[0015] Furthermore, the third rectifier filter circuit includes a diode D4, an inductor L4, a capacitor C6 and a capacitor C7, one end of the capacitor C6 and one end of the capacitor C7 are connected to the two ends of the inductor L4 respectively, and the other end of the capacitor C6 and the other end of the capacitor C7 are connected to the power supply V OUT 5V Ground, one end of the inductor L4 is connected to the cathode of the diode D4, and the other end of the inductor L4 is connected to the positive electrode of the power supply output V OUT 5V, the positive terminal of diode D4 is connected to the output end of the secondary winding of transformer T2.

[0016] Furthermore, the second power supply overvoltage protection circuit includes a resistor R7, a resistor R8, a third reference voltage circuit and a comparison amplifier U3, wherein one end of the resistor R7 is connected to the positive electrode V OUT 5V , the other end of resistor R7 is connected to one end of resistor R8, and the other end of resistor R8 is connected to the power supply V OUT 5V The positive input terminal of the comparison amplifier U3 is connected to the other end of the resistor R7, the output terminal of the third reference voltage circuit is connected to the negative terminal of the comparison amplifier U3, and the output terminal of the comparison amplifier U3 is connected to the second power supply pulse width modulation circuit.

[0017] Furthermore, the T1 transformer and the T2 transformer are flyback transformers, wherein the turns ratio of the primary winding of the T1 transformer to the two secondary windings is 120:75, and the turns ratio of the primary winding of the T2 transformer to the secondary winding is 100:60.

[0018] Compared with the prior art, the utility model has the following beneficial technical effects:

[0019] The utility model provides a switching voltage-stabilized power supply for drilling tools, comprising a voltage-stabilized power supply, wherein the output end of the voltage-stabilized power supply is connected to the input end of a power supply undervoltage protection circuit, and is respectively connected to the input end of a T1 transformer, the input end of a T2 transformer, the input end of a first power supply pulse width modulation circuit, and the input end of a second power supply pulse width modulation circuit through a reverse protection and filtering circuit; the output end of the power supply undervoltage protection circuit is connected to the input end of the first power supply pulse width modulation circuit and the input end of the second power supply pulse width modulation circuit; the output end of the primary winding of the T1 transformer is connected to the first power supply pulse width modulation circuit through a power switching device Q1; the secondary first winding of the T1 transformer is respectively connected to the input end of a first power supply error feedback circuit 7 and the input end of a first power supply overvoltage protection circuit through a first rectifier and filter circuit; the secondary second winding of the T1 transformer is connected to a second rectifier and filter circuit; the input end of the first power supply pulse width modulation circuit is also connected to the first power supply error feedback circuit 7 and the input end of the first power supply overvoltage protection circuit. The output end of the error feedback circuit and the output end of the first power supply overvoltage protection circuit; the source of the power switching device Q1 is connected to one end of the current sampling resistor R3, and the other end of the current sampling resistor R3 is connected to the negative electrode of the voltage-stabilized power supply 1; the output end of the primary winding of the T2 transformer is connected to the second power supply pulse width modulation circuit via the power switching device Q2, and the secondary winding of the T2 transformer is respectively connected to the input end of the second power supply error feedback circuit and the input end of the second power supply overvoltage protection circuit via the third rectifier and filter circuit; the input end of the second power supply pulse width modulation circuit is respectively connected to the output end of the second power supply error feedback circuit and the output end of the second power supply overvoltage protection circuit; the source of the power switching device Q2 is connected to one end of the current sampling resistor R4, and the other end of the current sampling resistor R4 is connected to the negative electrode of the voltage-stabilized power supply; the present application has the characteristics of high power and stable output, simplifies the design of the intelligent drilling tool circuit system and the volume of the circuit board, and improves the stability of the circuit system applied to the intelligent drilling tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The utility model is a circuit diagram of a switching voltage-stabilized power supply applied to a drilling tool.

[0021] In the figure: 1. regulated power supply; 2. power supply undervoltage protection circuit; 3. reverse protection and filtering circuit; 4. T1 transformer; 5. first rectifier and filter circuit; 6. second rectifier and filter circuit; 7. first power supply error feedback circuit; 8. first power supply pulse width modulation circuit; 9. first power supply overvoltage protection circuit; 10. T2 transformer; 11. third rectifier and filter circuit; 12. second power supply error feedback circuit; 13. second power supply pulse width modulation circuit; 14. second power supply overvoltage protection circuit. DETAILED DESCRIPTION

[0022] The present invention will be further described in detail below in conjunction with the accompanying drawings, which are intended to explain the present invention rather than to limit it.

[0023] In order to enable those skilled in the art to better understand the solution of the utility model, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the utility model.

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

[0025] The utility model provides a switching voltage-stabilized power supply for drilling tools, such as Figure 1As shown, it includes a regulated power supply 1, the output end of the regulated power supply 1 is connected to the input end of the power supply undervoltage protection circuit 2, and is respectively connected to the input end of the T1 transformer 4, the input end of the T2 transformer 10, the input end of the first power supply pulse width modulation circuit 8, and the input end of the second power supply pulse width modulation circuit 13 through the reverse protection and filtering circuit 3; the output end of the power supply undervoltage protection circuit 2 is connected to the input end of the first power supply pulse width modulation circuit 8 and the input end of the second power supply pulse width modulation circuit 13; the output end of the primary winding of the T1 transformer 4 is connected to the first power supply pulse width modulation circuit 8 through the power switching device Q1; the secondary first winding of the T1 transformer 4 is respectively connected to the input end of the first power supply error feedback circuit 7 and the input end of the first power supply overvoltage protection circuit 9 through the first rectifier and filter circuit 5; the secondary second winding of the T1 transformer 4 is connected to the second rectifier and filter circuit 6; the first The input end of the power pulse width modulation circuit 8 is also connected to the output end of the first power error feedback circuit 7 and the output end of the first power overvoltage protection circuit 9; the source of the power switch device Q1 is connected to one end of the current sampling resistor R3, and the other end of the current sampling resistor R3 is connected to the negative electrode of the voltage-stabilized power supply 1; the output end of the primary winding of the T2 transformer 10 is connected to the second power pulse width modulation circuit 13 through the power switch device Q2, and the secondary winding of the T2 transformer 10 is respectively connected to the input end of the second power error feedback circuit 12 and the input end of the second power overvoltage protection circuit 14 through the third rectifier and filter circuit 11; the input end of the second power pulse width modulation circuit 13 is respectively connected to the output end of the second power error feedback circuit 12 and the output end of the second power overvoltage protection circuit 14; the source of the power switch device Q2 is connected to one end of the current sampling resistor R4, and the other end of the current sampling resistor R4 is connected to the negative electrode of the voltage-stabilized power supply 1.

[0026] Specifically, in the present embodiment, the first rectifier and filter circuit 5 is a +12V rectifier and filter circuit, the second rectifier and filter circuit 6 is a -12V rectifier and filter circuit, the first power supply error feedback circuit 7 is a ±12V power supply error feedback circuit, the first power supply pulse width modulation circuit 8 is a ±12V power supply pulse width modulation circuit, the first power supply overvoltage protection circuit 9 is a ±12V power supply overvoltage protection circuit, the third rectifier and filter circuit 11 is a 5V rectifier and filter circuit, the second power supply error feedback circuit 12 is a 5V power supply error feedback circuit, and the second power supply pulse width modulation circuit 13 is a 5V power supply pulse width modulation circuit. The second power supply overvoltage protection circuit 14 is a 5V power supply overvoltage protection circuit, the regulated power supply 1 is a DC regulated power supply, and its output voltage is between 24V and 36V, and the maximum rated power is greater than 25W; the first power supply error feedback circuit 7 and the second power supply error feedback circuit 12 both use the UC1901 chip; the core chips of the second power supply pulse width modulation circuit 13 and the first power supply pulse width modulation circuit 8 both use the HV9110NG chip with a self-starting function, and the switching frequencies of the second power supply pulse width modulation circuit 13 and the first power supply pulse width modulation circuit 8 are designed to be 1MHz.

[0027] Preferably, in this embodiment, the drain of the power switch device Q1 is connected to the output end of the primary winding of the T1 transformer 4, the gate is connected to the output end of the first power pulse width modulation circuit 8, and the source is connected to the input end of the first power pulse width modulation circuit 8 and one end of the current sampling resistor R3;

[0028] The power switch device Q2 has a drain connected to the output end of the primary winding of the T2 transformer 10, a gate connected to the output end of the second power pulse width modulation circuit 13, and a source connected to the input end of the second power pulse width modulation circuit 13 and one end of the current sampling resistor R4.

[0029] Preferably, in the present embodiment, the power supply undervoltage protection circuit 2 comprises a first reference voltage circuit, a resistor R1, a resistor R2 and a comparison amplifier U1; the first reference voltage circuit adopts an LM25017 chip, the input end of the first reference voltage circuit and one end of the resistor R1 are both connected to the positive electrode of the output end of the voltage-stabilized power supply 1, the output end of the first reference voltage circuit is connected to the negative input end of the comparison amplifier U1, the resistor R1 and the resistor R2 are connected in series and then connected to the positive and negative electrodes of the voltage-stabilized power supply 1, the positive input end of the comparison amplifier U1 is connected to the series node of the resistor R1 and the resistor R2, and the output end is connected to the input end of the first power supply pulse width modulation circuit 8 and the input end of the second power supply pulse width modulation circuit 13.

[0030] Preferably, in this embodiment, the reverse protection and filtering circuit 2 includes a diode D1, an inductor L1 and a capacitor C1, the positive electrode of the diode D1 is connected to the positive electrode of the output end of the voltage-stabilized power supply 1, the negative electrode of the diode D1 is connected to one end of the inductor L1, the other end of the inductor L1 is connected to one end of the capacitor C1 and the input end of the primary winding of the T1 transformer 4, and the other end of the capacitor C1 is connected to the ground of the voltage-stabilized power supply 1.

[0031] Preferably, in this embodiment, the first rectifier filter circuit 5 includes a diode D2, an inductor L2, a capacitor C2 and a capacitor C3, one end of the capacitor C2 and one end of the capacitor C3 are respectively connected to the two ends of the inductor L2, and the other end of the capacitor C2 and the other end of the capacitor C3 are both connected to the power supply V OUT﹢12V Ground, one end of the inductor L2 is connected to the cathode of the diode D2, and the other end of the inductor L2 is connected to the positive output terminal of the power supply V OUT﹢12V , the positive terminal of the diode D2 is connected to the output end of the first secondary winding of the T1 transformer 4.

[0032] Preferably, in this embodiment, the second rectifier filter circuit 6 includes a diode D3, an inductor L3, a capacitor C4 and a capacitor C5, one end of the capacitor C4 and one end of the capacitor C5 are connected to the two ends of the inductor L3 respectively, and the other end of the capacitor C2 and the other end of the capacitor C are connected to the power output terminal V OUT-12V , the first end of the inductor L3 is connected to the cathode end of the diode D3, and the other end of the inductor L3 is connected to the power supply V OUT-12V The anode terminal of the diode D2 is connected to the output terminal of the second secondary winding of the transformer T1 4 .

[0033] Preferably, in this embodiment, the first power supply overvoltage protection circuit 9 includes a resistor R5, a resistor R6, a second reference voltage circuit and a comparison amplifier U2, and one end of the resistor R5 is connected to the positive electrode V OUT﹢12V , the other end of resistor R5 is connected to one end of resistor R6, and the other end of resistor R6 is connected to the power supply V OUT﹢12V The positive input terminal of the comparison amplifier U2 and the input terminal of the second reference voltage circuit are respectively connected to the two ends of the resistor R5; the second reference voltage circuit adopts the LM2576 chip, the output terminal of the second reference voltage circuit is connected to the negative terminal of the comparison amplifier U2, and the output terminal of the comparison amplifier is connected to the ±12V first power supply pulse width modulation circuit 8.

[0034] Preferably, in this embodiment, the third rectifier filter circuit 11 includes a diode D4, an inductor L4, a capacitor C6 and a capacitor C7, one end of the capacitor C6 and one end of the capacitor C7 are connected to the two ends of the inductor L4 respectively, and the other end of the capacitor C6 and the other end of the capacitor C7 are connected to the power supply V OUT 5VGround, one end of the inductor L4 is connected to the cathode of the diode D4, and the other end of the inductor L4 is connected to the positive electrode of the power supply output V OUT 5V The positive terminal of the diode D4 is connected to the output end of the secondary winding of the transformer T2 10 .

[0035] Preferably, in this embodiment, the second power supply overvoltage protection circuit 14 includes a resistor R7, a resistor R8, a third reference voltage circuit and a comparison amplifier U3, and one end of the resistor R7 is connected to the positive electrode V OUT 5V , the other end of resistor R7 is connected to one end of resistor R8, and the other end of resistor R8 is connected to the power supply V OUT 5V The positive input terminal of the comparison amplifier U3 is connected to the other end of the resistor R7 , the output terminal of the third reference voltage circuit is connected to the negative terminal of the comparison amplifier U3 , and the output terminal of the comparison amplifier U3 is connected to the second power supply pulse width modulation circuit 13 .

[0036] Preferably, in this embodiment, the T1 transformer 4 and the T2 transformer 10 are flyback transformers, wherein the turns ratio of the primary winding of the T1 transformer 4 to the two secondary windings is 120:75, and the turns ratio of the primary winding to the secondary winding of the T2 transformer 10 is 100:60.

[0037] It should be noted that, in this embodiment, the first reference voltage circuit is a 5V reference voltage circuit, the second reference voltage circuit is a 3.3V reference voltage circuit, and the third reference voltage circuit is a 3.3V reference voltage circuit; the power supply V OUT﹢12V Ground, power supply V OUT-12V Ground, power supply V OUT 5V The ground is a common ground, that is, the three points are connected and share a common ground with the voltage-regulated power supply 1.

[0038] The utility model has the following functions when in use:

[0039] The voltage stabilizer 1 is a power supply, which provides a DC stabilized voltage in the range of 24V to 36V.

[0040] The power supply undervoltage protection circuit 2 samples the output voltage of the voltage-stabilized power supply 1 and compares it with the 5V reference voltage. When the sampled value is higher than 5V, the comparison amplifier U1 outputs a high level, and when the sampled value is lower than 5V, the comparison amplifier U1 outputs a low level. The comparison amplifier U1 transmits the output result to the first power supply pulse width modulation circuit 8 and the second power supply pulse width modulation circuit 13.

[0041] The reverse protection and filtering circuit 3 utilizes the unidirectional characteristic of the diode D1 to prevent the reverse voltage from burning the voltage-stabilized power supply 1 , and the LC filtering circuit filters the power supply to output a more stable direct current.

[0042] The T1 transformer 4 and the power switch device Q1 chop the DC power and convert it into high-frequency AC power, and use the electromagnetic induction principle to transmit the primary winding power to the first secondary winding and the second secondary winding, and at the same time connect the power supply end to the ±12V output end.

[0043] The first rectifying and filtering circuit 5 uses the diode D2 to perform half-wave rectification on the high-frequency AC power output by the first secondary winding of the T1 transformer 4. The capacitor C2, the capacitor C3 and the inductor L2 form a π-type filter to filter out the ripple component in the +12V output power.

[0044] The second rectifying and filtering circuit 6 uses the diode D3 to perform half-wave rectification on the high-frequency AC power output by the second secondary winding of the T1 transformer 4. The capacitor C4, the capacitor C5 and the inductor L3 form a π-type filter to filter out the ripple component in the -12V output power.

[0045] The first power supply error feedback circuit 7 samples the actual +12V output voltage value, compares it with the ideal value +12V to obtain the error between the two, and amplifies the error by gain and transmits it to the first power supply pulse width modulation circuit 8.

[0046] The first power supply pulse width modulation circuit 8 collects the source current of the power switch device Q1 through the resistor R3, and controls the switch of the power switch device Q1 to convert the DC power into high-frequency AC power according to the collection result of the source current of Q1 and the output result of the first power supply error feedback circuit 7. In addition, the power switch device Q1 is controlled to work or not according to the output results of the comparison amplifier U1 of the power supply undervoltage protection circuit 2 and the comparison amplifier U2 of the first power supply overvoltage protection circuit 9, thereby controlling whether there is ±12V power output.

[0047] The first power supply overvoltage protection circuit 9 samples the positive 12V actual output voltage using resistors R5 and R6, and compares it with the 3.3V reference voltage. When the sampled value is higher than 3.3V, the comparison amplifier U2 outputs a low level, and when the sampled value is lower than 3.3V, the comparison amplifier U2 outputs a high level. The comparison amplifier U2 transmits the output result to the first power supply pulse width modulation circuit 8.

[0048] The T2 transformer 10 and the power switch device Q2 chop the DC power and convert it into high-frequency AC power, and use the principle of electromagnetic induction to transfer the primary winding power to the secondary winding.

[0049] The third rectifying and filtering circuit 11 uses the diode D4 to perform half-wave rectification on the high-frequency AC power output by the secondary winding of the T2 transformer 10. The capacitor C6, the capacitor C7 and the inductor L4 form a π-type filter to filter out the ripple component in the 5V output power.

[0050] The second power supply error feedback circuit 12 samples the actual 5V output voltage value, compares it with the ideal value 5V to obtain the error between the two, and amplifies the error by gain and transmits it to the second power supply pulse width modulation circuit 13.

[0051] The second power supply pulse width modulation circuit 13 collects the source current of the power switch device Q2 through the resistor R4, and controls the switch of the power switch device Q2 to convert the DC power into high-frequency AC power based on the collection result of the source current of Q2 and the output result of the second power supply error feedback circuit 12. In addition, the power switch device Q2 is controlled to work or not according to the output results of the comparison amplifier U1 of the power supply undervoltage protection circuit 2 and the comparison amplifier U3 of the second power supply overvoltage protection circuit 14, thereby controlling whether there is 5V power output.

[0052] The second power supply overvoltage protection circuit 14 samples the actual output voltage of 5V using resistors R7 and R8, and compares it with the 3.3V reference voltage. When the sampled value is higher than 3.3V, the comparison amplifier U3 outputs a low level, and when the sampled value is lower than 3.3V, the comparison amplifier U3 outputs a high level. The comparison amplifier U3 transmits the output result to the second power supply pulse width modulation circuit 13.

[0053] The working principle of the utility model is:

[0054] like Figure 1 As shown, the reverse protection and filtering circuit 3 utilizes the unidirectional characteristic of the diode D1 to prevent the reverse voltage from burning the voltage-stabilized power supply 1, thereby protecting the power supply. The LC filter composed of the inductor L1 and the capacitor C1 filters the output voltage of the power supply to obtain a more stable direct current and transmit it to the primary winding of the T1 transformer 4.

[0055] The power switch device Q1 chops the DC power of the primary winding of the T1 transformer 4 into high-frequency AC power in a high-speed switching state. According to the principle of electromagnetic induction, the T1 transformer 4 transmits the high-frequency power of the primary winding to the first secondary winding and the second secondary winding. D2 and the π-type filter in the first rectifier and filter circuit 5 perform half-wave rectification and filtering on the high-frequency AC power of the first secondary winding of the T1 transformer, and output +12 DC power. The second rectifier and filter circuit 6 has the same structure and working principle as the first rectifier and filter circuit 5, and the output is symmetrical and synchronous. The first power supply error feedback circuit 7 samples the actual output +12V voltage, compares it with the ideal value +12V to obtain the error between the two, and amplifies the error and transmits it to the first power supply pulse width modulation circuit 8. The resistor R3 samples the source output current of the power switch device Q1 and feeds it back to the first power supply pulse width modulation circuit 8. The first power supply pulse width modulation circuit 8 adjusts the duty cycle of the gate pulse output to the power switch device Q1 according to the Q1 source current sampling value and the output value of the first power supply error feedback circuit 7, thereby controlling the on-time and off-time interval of the power switch device Q1 to achieve the purpose of outputting a stable +12V.

[0056] The first power supply overvoltage protection circuit 9 samples the positive 12V actual output voltage using resistors R5 and R6, and compares it with the 3.3V reference voltage. When the sampled value is higher than 3.3V, the comparison amplifier U2 outputs a low level, and when the sampled value is lower than 3.3V, the comparison amplifier U2 outputs a high level. The comparison amplifier U2 transmits the output result to the first power supply pulse width modulation circuit 8. The power supply undervoltage protection circuit 2 samples the output voltage of the voltage-stabilized power supply 1 and compares it with the 5V reference voltage. When the sampled value is higher than 5V, the comparison amplifier U1 outputs a high level, and when the sampled value is lower than 5V, the comparison amplifier U1 outputs a low level. The comparison amplifier U1 transmits the output result to the first power supply pulse width modulation circuit 8. The power supply pulse width modulation circuit 8 outputs a pulse modulation signal to the power switch device Q1 when the output of the first power supply overvoltage protection circuit 9 and the output of the power supply undervoltage protection circuit 2 are both high levels. At this time, normal ±12V power is output. Otherwise, the power supply pulse width modulation circuit 8 stops outputting the pulse modulation signal, and there is no ±12V power output. Therefore, when the output of the voltage-stabilized power supply 1 is lower than the set value or the ±12V output is lower than the set value, the ±12 switching power supply circuit stops working to achieve the purpose of protecting the power supply, power circuit or load.

[0057] The -12V power supply circuit and the +12V power supply circuit share the primary winding of the T1 transformer, and the circuit structure, parameters and working principle are exactly the same, and the output is completely symmetrical and synchronous.

[0058] The circuit structure and working principle of the 5V switching regulated power supply are exactly the same as those of the above-mentioned ±12V switching regulated power supply, and will not be described in detail.

[0059] The threshold value of the power supply undervoltage protection circuit 2 of the utility model is set to 80% of the output voltage value of the voltage stabilizer 1, that is, when the actual output voltage value of the voltage stabilizer 1 is lower than 80% of the normal value, there is no ±12V, 5V output. The threshold value of the first power supply overvoltage protection circuit 9 is set to 15V, that is, when the voltage of the ±12V output terminal VOUT﹢12V, VOUT-12V exceeds the range of ±15V, there is no output. The threshold value of the second power supply overvoltage protection circuit 14 is set to 7.5V, that is, when the voltage of the 5V output terminal VOUT 5V exceeds 7.5V, there is no output.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the utility model.

Claims

1. A switching regulated power supply for drilling tools, It is characterized in that The invention comprises a voltage-stabilized power supply (1), wherein the output end of the voltage-stabilized power supply (1) is connected to the input end of a power supply undervoltage protection circuit (2), and is respectively connected to the input end of a T1 transformer (4), the input end of a T2 transformer (10), the input end of a first power supply pulse width modulation circuit (8), and the input end of a second power supply pulse width modulation circuit (13) through a reverse protection and filtering circuit (3); the output end of the power supply undervoltage protection circuit (2) is connected to the input end of the first power supply pulse width modulation circuit (8) and the input end of the second power supply pulse width modulation circuit (13); the output end of the primary winding of the T1 transformer (4) is connected to the first power supply pulse width modulation circuit (8) through a power switch device Q1; the secondary first winding of the T1 transformer (4) is respectively connected to the input end of a first power supply error feedback circuit (7) and the input end of a first power supply overvoltage protection circuit (9) through a first rectifier and filter circuit (5); the secondary second winding of the T1 transformer (4) is connected to the second rectifier and filter circuit (6 ); the input end of the first power supply pulse width modulation circuit (8) is also connected to the output end of the first power supply error feedback circuit (7) and the output end of the first power supply overvoltage protection circuit (9); the source of the power switch device Q1 is connected to one end of the current sampling resistor R3, and the other end of the current sampling resistor R3 is connected to the negative electrode of the voltage-stabilized power supply (1); the output end of the primary winding of the T2 transformer (10) is connected to the second power supply pulse width modulation circuit (13) through the power switch device Q2, and the secondary winding of the T2 transformer (10) is respectively connected to the input end of the second power supply error feedback circuit (12) and the input end of the second power supply overvoltage protection circuit (14) through the third rectifier filter circuit (11); the input end of the second power supply pulse width modulation circuit (13) is respectively connected to the output end of the second power supply error feedback circuit (12) and the output end of the second power supply overvoltage protection circuit (14); the source of the power switch device Q2 is connected to one end of the current sampling resistor R4, and the other end of the current sampling resistor R4 is connected to the negative electrode of the voltage-stabilized power supply (1).

2. A switching regulated power supply for drilling tools according to claim 1, It is characterized in that The power switch device Q1 has a drain connected to the output end of the primary winding of the T1 transformer (4), a gate connected to the output end of the first power pulse width modulation circuit (8), and a source connected to the input end of the first power pulse width modulation circuit (8) and one end of the current sampling resistor R3; The power switch device Q2 has a drain connected to the output end of the primary winding of the T2 transformer (10), a gate connected to the output end of the second power supply pulse width modulation circuit (13), and a source connected to the input end of the second power supply pulse width modulation circuit (13) and one end of the current sampling resistor R4.

3. A switching regulated power supply for drilling tools according to claim 1, It is characterized in that The power supply undervoltage protection circuit (2) comprises a first reference voltage circuit, a resistor R1, a resistor R2 and a comparison amplifier U1; the first reference voltage circuit adopts an LM25017 chip; the input end of the first reference voltage circuit and one end of the resistor R1 are both connected to the positive electrode of the output end of the voltage-stabilized power supply (1); the output end of the first reference voltage circuit is connected to the negative input end of the comparison amplifier U1; the resistor R1 and the resistor R2 are connected in series and then connected to the positive and negative electrodes of the voltage-stabilized power supply (1); the positive input end of the comparison amplifier U1 is connected to the series node of the resistor R1 and the resistor R2; and the output end is connected to the input end of the first power supply pulse width modulation circuit (8) and the input end of the second power supply pulse width modulation circuit (13).

4. A switching regulated power supply for drilling tools according to claim 1, It is characterized in that The reverse protection and filtering circuit (3) comprises a diode D1, an inductor L1 and a capacitor C1, wherein the positive electrode of the diode D1 is connected to the positive electrode of the output end of the voltage-stabilized power supply (1), the negative electrode of the diode D1 is connected to one end of the inductor L1, the other end of the inductor L1 is connected to one end of the capacitor C1 and the input end of the primary winding of the T1 transformer (4), and the other end of the capacitor C1 is connected to the ground of the voltage-stabilized power supply (1).

5. A switching regulated power supply for drilling tools according to claim 1, It is characterized in that The first rectifying and filtering circuit (5) comprises a diode D2, an inductor L2, a capacitor C2 and a capacitor C3, one end of the capacitor C2 and one end of the capacitor C3 are respectively connected to the two ends of the inductor L2, and the other end of the capacitor C2 and the other end of the capacitor C3 are both connected to the power supply V OUT﹢12V Ground, one end of the inductor L2 is connected to the cathode of the diode D2, and the other end of the inductor L2 is connected to the positive output terminal of the power supply V OUT﹢12V The anode terminal of the diode D2 is connected to the output terminal of the first secondary winding of the T1 transformer (4).

6. A switching regulated power supply for drilling tools according to claim 1, It is characterized in that The second rectifying and filtering circuit (6) comprises a diode D3, an inductor L3, a capacitor C4 and a capacitor C5, one end of the capacitor C4 and one end of the capacitor C5 are respectively connected to the two ends of the inductor L3, and the other end of the capacitor C2 and the other end of the capacitor C are both connected to the power supply output terminal V OUT-12V , the first end of the inductor L3 is connected to the cathode end of the diode D3, and the other end of the inductor L3 is connected to the power supply V OUT-12V The anode terminal of the diode D2 is connected to the output terminal of the second secondary winding of the T1 transformer (4).

7. A switching regulated power supply for drilling tools according to claim 1, It is characterized in that The first power supply overvoltage protection circuit (9) comprises a resistor R5, a resistor R6, a second reference voltage circuit and a comparison amplifier U2, wherein one end of the resistor R5 is connected to the positive electrode V of the power supply output terminal. OUT﹢12V , the other end of resistor R5 is connected to one end of resistor R6, and the other end of resistor R6 is connected to the power supply V OUT﹢12V The positive input terminal of the comparison amplifier U2 and the input terminal of the second reference voltage circuit are respectively connected to the two ends of the resistor R5; the second reference voltage circuit adopts the LM2576 chip, the output terminal of the second reference voltage circuit is connected to the negative terminal of the comparison amplifier U2, and the output terminal of the comparison amplifier is connected to the ±12V first power supply pulse width modulation circuit (8).

8. A switching regulated power supply for drilling tools according to claim 1, It is characterized in that The third rectifying and filtering circuit (11) comprises a diode D4, an inductor L4, a capacitor C6 and a capacitor C7, one end of the capacitor C6 and one end of the capacitor C7 are respectively connected to the two ends of the inductor L4, and the other end of the capacitor C6 and the other end of the capacitor C7 are both connected to the power supply V OUT5V Ground, one end of the inductor L4 is connected to the cathode of the diode D4, and the other end of the inductor L4 is connected to the positive electrode of the power supply output V OUT5V The positive terminal of the diode D4 is connected to the output end of the secondary winding of the transformer T2 (10).

9. A switching regulated power supply for drilling tools according to claim 1, It is characterized in that The second power supply overvoltage protection circuit (14) comprises a resistor R7, a resistor R8, a third reference voltage circuit and a comparison amplifier U3, wherein one end of the resistor R7 is connected to the positive electrode V OUT5V , the other end of resistor R7 is connected to one end of resistor R8, and the other end of resistor R8 is connected to the power supply V OUT5V The positive input terminal of the comparison amplifier U3 is connected to the other end of the resistor R7, the output terminal of the third reference voltage circuit is connected to the negative terminal of the comparison amplifier U3, and the output terminal of the comparison amplifier U3 is connected to the second power supply pulse width modulation circuit (13).

10. A switching regulated power supply for drilling tools according to claim 1, It is characterized in that The T1 transformer (4) and the T2 transformer (10) are flyback transformers, wherein the turns ratio between the primary winding and the two secondary windings of the T1 transformer (4) is 120:75, and the turns ratio between the primary winding and the secondary winding of the T2 transformer (10) is 100:60.

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