Low-power open-loop power supply for supplying power to frequency stabilization-machine shake drive circuit

Abstract

The invention provides a low-power open-loop power supply for supplying power to a frequency stabilization-mechanical jitter driving circuit, which adopts a nominal 15V power supply, has three outputs in total, and can be provided with a nominal 300V load and a pair of nominal + / -65V positive and negative balanced loads; a 15V power supply is filtered by a capacitor C101 and then supplies power to a subsequent power conversion topology, a transformer T101 adopts a push-pull self-excitation transformer, a main power primary side is a group of push-pull windings N1 and N2, the number of turns of N1 and N2 is consistent, the number of turns of N3 and N4 is a group of driving windings, the number of turns of N3 and N4 is consistent, the number of windings N5 and N6 is a transformer secondary side main power output winding, the winding N5 is used for outputting one path of 300V, and the winding N6 is used for outputting a pair of + / -65V. And all the windings are wound on the EPC13 magnetic core through a surface-mounted welding framework with ten pins. On the premise that application requirements are met, the size of the magnetic core of the transformer can be fully utilized, soft switching is achieved, the size of the transformer is reduced, and the cost of a control chip is saved.

Description

Technical Field

[0001] The invention belongs to the field of laser gyro inertial navigation systems, and in particular relates to a low-power open-loop power supply for supplying power to a frequency stabilization-machine dithering driving circuit. Background Art

[0002] In recent years, space three-axis laser gyroscopes have been widely used. As laser gyroscope inertial navigation systems are developed towards low cost and miniaturization, the frequency-stabilized drive power supply and machine-shake drive power supply that adapt to space three-axis laser gyroscopes are also facing the need to further reduce costs, reduce volume, and improve efficiency. Summary of the invention

[0003] The purpose of the present invention is to provide a low-power open-loop power supply for powering a frequency stabilization-machine jitter driving circuit, which reduces the volume, improves the efficiency and controls the cost while meeting the use requirements.

[0004] The technical solution adopted by the present invention to achieve the above-mentioned purpose is as follows:

[0005] The present invention provides a low-power open-loop power supply for supplying power to a frequency stabilization-machine jitter driving circuit, adopts a nominal 15V power supply, has three outputs in total, one is a nominal 300V load, and the other is a pair of nominal ±65V positive and negative balanced loads; the 15V power supply is filtered by a capacitor C101 to supply power to a subsequent power conversion topology, a transformer T101 adopts a push-pull self-excited transformer, a primary side of the main power is a group of push-pull windings N1 and N2, N1 and N2 have the same number of turns, windings N3 and N4 are a group of drive windings, the number of turns is the same, windings N5 and N6 are the secondary side main power output windings of the transformer, winding N5 is used to output one 300V, winding N6 is used to output a pair of ±65V, and all windings are wound on an EPC13 magnetic core through a 10-pin surface mount solder skeleton.

[0006] Furthermore, the transformer T101 has two NMOS tubes V101 and V102 of the same model on the primary side, two driving resistors R102 and R103 of the same model, a power inductor L102 with a large inductance value, a voltage regulator tube D101 that provides the gate turn-on voltage required for self-excited starting, a voltage regulator tube current limiting resistor R101 and a resonant capacitor C102 with a very small capacitance value.

[0007] The two primary windings N1 and N2 have the same number of turns and the same winding direction, the center tap point is connected to the power inductor L102, the other end of the winding N1 is connected to the drain of the NMOS tube V101, and the other end of the winding N2 is connected to the drain of the NMOS tube V102; the non-same-name ends of the windings N3 and N4 are connected to the cathode of the voltage-stabilizing diode D101, the other end of the winding N3 is connected to the driving resistor R102 of the NMOS tube V101, and the other end of the winding N4 is connected to the driving resistor R102 of the NMOS tube V101; the driving resistor R102 is connected to the gate of the NMOS tube V101, and the driving resistor R103 is connected to the gate of the NMOS tube V103.

[0008] The driving winding voltage changes synchronously with the primary winding voltage to achieve zero-voltage switching on and off of the NMOS tube.

[0009] Furthermore, the voltage stabilization value of the voltage regulator tube D101 should be higher than the start-up voltage of the NMOS tubes V101 and V102 but not too high, so as to ensure that the converter T101 can be self-started without overcurrent.

[0010] Furthermore, after the secondary output winding N5 of the transformer T101 is a rectifier-doubler circuit and a linear voltage stabilizing filter circuit, the rectifier-doubler circuit includes two switching diodes D102 and D103 of the same model and two capacitors C104 and C105 of the same model, the linear voltage stabilizing filter circuit after the winding N5 includes an NPN transistor V103, an output voltage stabilizing diode or a voltage stabilizing diode series branch D106, a current limiting resistor R104 working with D106 and an output capacitor C106, and C106 outputs a nominal voltage of 300V.

[0011] Furthermore, after the output winding N6 of the transformer T101 is a rectifier filter circuit, which includes two switching diodes D109 and D110 of the same model and two capacitors C107 and C108 of the same model. The nominal voltages on C107 and C108 are +65V and -65V respectively.

[0012] Furthermore, the current of the rectification-voltage doubling circuit after the winding N5 is controlled within 10 mA to ensure that the voltage ripple thereon is small when the capacitance of C101 and C105 is small.

[0013] The beneficial effects of the present invention compared with the prior art are as follows:

[0014] The present invention proposes a low-power open-loop power supply for powering a frequency stabilization-machine jitter driving circuit. Compared with the closed-loop power supply solution of the traditional low-power flyback, it adopts a push-pull self-excitation solution, does not require a control chip, and uses a small-sized EPC13 core transformer to provide 1 nominal 300V power supply and 1 pair of nominal ±65V power supplies. Under the premise of meeting the application requirements, the transformer core size can be fully utilized and soft switching can be realized, which reduces the transformer volume and saves the cost of the control chip. The present invention realizes the zero-voltage opening and closing of the switching device, and there is no dead zone, and the transformer has no "ringing" working condition. Compared with the high-voltage low-power flyback converter, the efficiency is improved and it has certain application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The included drawings are used to provide a further understanding of the embodiments of the present invention, which constitute a part of the specification, are used to illustrate the embodiments of the present invention, and together with the text description, explain the principles of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0016] Figure 1 A schematic diagram of a low-power open-loop power supply for powering a frequency stabilization-machine jitter driving circuit is shown according to a specific embodiment of the present invention. DETAILED DESCRIPTION

[0017] It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] As a low-power open-loop power supply for powering the frequency stabilization-machine jitter driving circuit provided by an embodiment of the present invention, a nominal 15V power supply is adopted, no driving control chip is required, and a push-pull self-excitation scheme is adopted. It is a low-power open-loop power supply that meets the power supply of the frequency stabilization driving circuit and the machine jitter driving circuit of the space three-axis laser gyroscope. The power supply of the frequency stabilization driving circuit refers to outputting a nominal 300V / 5mA power supply; the power supply of the machine jitter driving circuit refers to outputting a pair of nominal ±65V / 25mA power supplies.

[0019] The 15V power supply is a stabilized power supply with good stability, and is filtered by capacitor C101 to supply power to the subsequent power conversion topology.

[0020] The push-pull self-excitation scheme adopts a small-sized surface-mount solder transformer T101, the magnetic core of T101 is an EPC13 magnetic core, and the skeleton is a 10-pin skeleton, which fully utilizes the magnetic core size and the number of skeleton pins to meet the small size requirements. The primary side of the transformer T101 in the push-pull self-excitation scheme requires a power inductor L102 with a large inductance value; the primary side of the transformer in the push-pull self-excitation scheme requires two N-channel field effect transistors (NMOS tubes) V101 and V102 of the same model; the primary side of the transformer in the push-pull self-excitation scheme requires a voltage regulator diode D101 that provides a self-excitation start-up voltage for the gates of V101 and V102, a current limiting resistor R101 that cooperates with D101, and a C102 that enables the converter to work in a self-excitation oscillation state; the voltage regulation value of D101 should be higher than the start-up voltage of V101 and V102 but not too high, so as to ensure that the push-pull circuit can be self-excited and start without overcurrent.

[0021] The transformer T101 comprises five windings, each of which has the same-name terminals as shown in FIG. Figure 1 As shown, a total of 10 pins of the skeleton are occupied. The transformer T101 main power primary winding is the common push-pull converter windings N1 and N2, the two windings have the same number of turns and the same winding direction, the center tap A is connected to the power inductor L102, the other end of N1 is connected to the drain of V101, and the other end of N2 is connected to the drain of V102; the transformer T101 includes two driving windings N3 and N4 with the same number of turns, N3 and N4 have one end (non-same name end) connected to the cathode of the voltage zener diode D101, and the other end of N3 is connected to the driving resistor R1 of V101. 02, the other end of N4 is connected to the driving resistor R102 of V101; the driving resistor R102 is connected to the gate of V101, and the driving resistor R103 is connected to the gate of V103; the transformer T101 includes a secondary winding N5 with more turns and a secondary winding N6 with fewer turns. N5 is connected to the rectifier-double voltage circuit and a linear voltage stabilizing filter circuit to output a nominal 300V / 5mA power supply, and N6 is connected to the rectifier filter circuit to output a nominal ±65V / 25mA positive and negative balanced power supply. All windings are wound on the EPC13 core through a 10-pin surface mount solder skeleton. All 10 pins of the skeleton are fully utilized to achieve the purpose of small size of the transformer.

[0022] After the secondary output winding N5 of the transformer T101, there is a rectifier-double voltage circuit and a linear voltage stabilizing filter circuit. The rectifier-double voltage circuit includes two switch diodes D102 and D103 of the same model and two capacitors C104 and C105 of the same model; the linear voltage stabilizing filter circuit includes an NPN transistor V103, an output voltage stabilizing diode (or a voltage stabilizing diode series branch) D106, a current limiting resistor R104 working with D106, and an output capacitor C106.

[0023] After the output winding N6 of the transformer T101 is a rectifier filter circuit, which includes two switching diodes D109 and D110 of the same model and two capacitors C107 and C108 of the same model. The nominal voltages on C107 and C108 are +65V and -65V respectively.

[0024] When the 300V output load is a stable load, and the ±65V output load is a stable load with positive and negative balance and 15V power supply, the voltage regulation value of D101 will be higher than the turn-on voltage of V101 and V102 at a stage, and because the turn-on voltages of V101 and V102 are not completely consistent, when a certain NMOS is turned on, due to the existence of the resonant capacitor C102 and the drive winding, the gate voltage of the turned-on NMOS will further increase, and the gate voltage of the non-turned-on NMOS will further decrease, and the positive feedback formed will cause one NMOS to turn on and the other NMOS to turn off.

[0025] When the primary winding voltage of the transformer T101 continues to increase, and the voltage converted to the secondary side causes the secondary side diode to conduct, the primary voltage and the secondary voltage will be constant, and the transformer will output the primary energy directly to the secondary side and provide one 300V output and one ±65V output.

[0026] When the energy transmission continues for a period of time, due to the effects of C102, L102, excitation inductance and load energy consumption, the secondary winding current will drop to zero, and the primary winding voltage and the secondary winding voltage will decrease in the form of resonance. After decreasing to a certain level, the NMOS that was originally turned on will be turned off, and the NMOS that was originally turned off will be turned on. The NMOS that is turned on this time will repeat the working state of the NMOS that was turned on last time. This time the transformer transmits energy to the secondary side and will provide one 300V output and one output of ±65V.

[0027] The voltage of the driving winding changes synchronously with the voltage of the primary winding. When the NMOS is turned on and off, the voltage of the primary winding is close to zero, and the voltage of the NMOS is also close to zero, so the zero-voltage turning on and off of the NMOS can be achieved.

[0028] The push-pull self-excitation scheme R101, C102, L102, R102, R103 and the excitation inductance parameters of the primary main power winding of the transformer should be designed and debugged in combination with the output power so that the transformer T101 can work stably in a non-saturated state and at a suitable self-excited oscillation frequency.

[0029] The current of the rectifier-doubler circuit after N5 is controlled within 10mA to ensure that the voltage pulsation on C101 and C105 is small when the capacitance is small. The rectifier filter circuit of N6 is simple in structure and is suitable for 300kHz or above sinusoidal drive power supply applications such as machine jitter drive circuit (the load can be regarded as a positive and negative balanced load for a long time). The peak current should be controlled within 30mA.

[0030] The present invention is further described below in conjunction with a specific embodiment.

[0031] Figure 1 The topology of a low-power open-loop power supply for the frequency stabilization-machine jitter drive circuit is illustrated. This topology uses a nominal 15V power supply. Because it is an open-loop power supply, the 15V power supply should be a voltage-stabilized power supply with good stability. After filtering through capacitor C101, it can power the subsequent power conversion topology. Transformer T101 is a push-pull self-excited transformer. The primary side of the main power is a set of push-pull windings N1 and N2. The number of turns of N1 and N2 is the same, and the number of turns of windings N3 and N4 is the same. It is a set of drive windings. Windings N5 and N6 are the secondary side main power output windings of the transformer. Depending on the output voltage, N5 has more turns and is used to output 1 300V, and N6 has fewer turns and is used to output a pair of ±65V. All windings are wound on the EPC13 core through a 10-pin surface-mount solder skeleton. All 10 pins of the skeleton are fully utilized to achieve the purpose of small size of the transformer. The pin numbers and the same-name terminal markings are as follows: Figure 1 As shown, N1 and N2 both have 20 turns, N3 and N4 both have 7 turns, N5 has 219 turns, and N6 has 88 turns.

[0032] In order to make the transformer T101 work in a non-saturated push-pull self-excited oscillation state, as Figure 1 As shown, the transformer primary side needs to select two N-channel field effect transistors (NMOS tubes) of the same model, such as LN25N130J, SO-8 package, with a turn-on voltage of about 3.5V; two driving resistors R102 and R103 of the same model are selected from 100Ω-300Ω; a power inductor L102 with a larger inductance value is selected from 470uH; a voltage regulator D101 that provides the gate turn-on voltage required for self-excited startup is selected from MM3Z4V3, with a nominal voltage regulation value of 4.3V; the current limiting resistor R101 is selected from 6.2kΩ; the resonant capacitor C102 has a capacitance of 0.33nF; the primary side excitation inductance is about 200uH.

[0033] After the secondary output winding N5 of transformer T101, there is a rectifier-double voltage circuit and a linear voltage stabilizing filter circuit. As shown in the figure, the rectifier-double voltage circuit includes two switch diodes D102 and D103 of the same model and two capacitors C104 and C105 of the same model. The linear voltage stabilizing filter circuit after N5 includes an NPN transistor V103, an output voltage stabilizing diode (or a voltage stabilizing diode series branch) D106, a current limiting resistor R104 working with D106, and an output capacitor C106. C106 outputs a nominal 300V voltage. Since the 300V output current is very small (within 5mA) and there is a voltage stabilizing diode, C104, C105, and C106 are all selected to be 630V / 100nF to meet the ripple within 0.5V.

[0034] After the output winding N6 of the transformer T101 is a rectifier filter circuit, which includes two switch diodes D109 and D110 of the same model and two capacitors C107 and C108 of the same model. The nominal voltages on C107 and C108 are +65V and -65V respectively. Since the load current required for ±65V is relatively large, the peak current of a single load is about 25mA, and there is a positive and negative alternating load that changes sinusoidally at 300kHz-500kHz (it can be regarded as a positive and negative balanced load for a long time), the capacitance of C107 and C108 should be selected to be above 2.2uF to meet the use requirements.

[0035] When the open-loop power supply outputs one 300V / 5mA and one pair of ±65 / 25mA, the self-excited switching frequency should be above 40kHz to ensure that the transformer operates in a non-saturated state under three temperature conditions.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-power open-loop power supply for a frequency stabilization-machine jitter driving circuit, characterized in that: A nominal 15V power supply is used, with a total of three outputs, one nominal 300V load, and a pair of nominal ±65V positive and negative balanced loads; the 15V power supply is filtered by capacitor C101 to power the subsequent power conversion topology. Transformer T101 uses a push-pull self-excited transformer. The primary side of the main power is a group of push-pull windings N1 and N2. N1 and N2 have the same number of turns. Windings N3 and N4 are a group of drive windings with the same number of turns. Windings N5 and N6 are the main power output windings on the secondary side of the transformer. Winding N5 is used to output 1 300V, and winding N6 is used to output a pair of ±65V. All windings are wound on the EPC13 core through a 10-pin surface mount solder skeleton.

2. A low-power open-loop power supply for powering a frequency stabilization-machine jitter driving circuit according to claim 1, characterized in that: The transformer T101 has two NMOS tubes V101 and V102 of the same model on the primary side, two driving resistors R102 and R103 of the same model, a power inductor L102 with a large inductance value, a voltage regulator D101 that provides the gate opening voltage required for self-excited starting, a voltage regulator current limiting resistor R101 and a resonant capacitor C102 with a very small capacitance. The two primary windings N1 and N2 have the same number of turns and the same winding direction, the center tap point is connected to the power inductor L102, the other end of the winding N1 is connected to the drain of the NMOS tube V101, and the other end of the winding N2 is connected to the drain of the NMOS tube V102; the non-same-name ends of the windings N3 and N4 are connected to the cathode of the voltage-stabilizing diode D101, the other end of the winding N3 is connected to the driving resistor R102 of the NMOS tube V101, and the other end of the winding N4 is connected to the driving resistor R102 of the NMOS tube V101; the driving resistor R102 is connected to the gate of the NMOS tube V101, and the driving resistor R103 is connected to the gate of the NMOS tube V103. The driving winding voltage changes synchronously with the primary winding voltage to achieve zero-voltage switching on and off of the NMOS tube.

3. A low-power open-loop power supply for powering a frequency stabilization-machine jitter driving circuit according to claim 2, characterized in that: The voltage stabilization value of the voltage stabilizing tube D101 should be higher than the start-up voltage of the NMOS tubes V101 and V102 but not too high, so as to ensure that the converter T101 can be self-started without overcurrent.

4. A low-power open-loop power supply for powering a frequency stabilization-machine jitter driving circuit according to claim 2, characterized in that: After the secondary output winding N5 of the transformer T101 is a rectifier-doubler circuit and a linear voltage stabilizing filter circuit. The rectifier-doubler circuit includes two switching diodes D102 and D103 of the same model and two capacitors C104 and C105 of the same model. The linear voltage stabilizing filter circuit after the winding N5 includes an NPN transistor V103, an output voltage stabilizing diode or a voltage stabilizing diode series branch D106, a current limiting resistor R104 working with D106 and an output capacitor C106. C106 outputs a nominal voltage of 300V.

5. A low-power open-loop power supply for powering a frequency stabilization-machine jitter driving circuit according to claim 2, characterized in that: After the output winding N6 of the transformer T101 is a rectifier filter circuit, which includes two switching diodes D109 and D110 of the same model and two capacitors C107 and C108 of the same model. The nominal voltages on C107 and C108 are +65V and -65V respectively.

6. A low-power open-loop power supply for powering a frequency stabilization-machine jitter driving circuit according to claim 2, characterized in that: The current of the rectification-voltage doubling circuit after the winding N5 is controlled within 10 mA to ensure that the voltage ripple on C101 and C105 is small when the capacitance values ​​thereof are small.

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