阅读说明：本技术 一种低频下可靠驱动线圈负载的电路 (Circuit for reliably driving coil load under low frequency ) 是由 张�成 张晨 于 2019-06-25 设计创作，主要内容包括：本发明公开了一种低频下可靠驱动线圈负载的电路,适用于使用低频信号驱动线圈负载的场合,包括第一开关电路、第二开关电路和输入控制电路。第一开关电路、第二开关电路均包含整流滤波模块、变压器、原边开关驱动模块、信号反馈模块,相位相反的交流电分别连接第一开关电路与第二开关电路的输入,经其中的整流滤波、信号反馈等处理后输出,连接线圈负载的两端；输入控制电路包括变压器和偏置消除模块,变压器原边接收低频信号,副边输出经偏置消除模块的处理后向第一开关电路、第二开关电路中的开关器件输出开关信号。本发明所述电路拓扑简单,容易实现,减少了成本,增强了驱动能力,降低了直流偏置对线圈类负载的影响。(The invention discloses a circuit for reliably driving a coil load under low frequency, which is suitable for occasions using low-frequency signals to drive the coil load. The first switch circuit and the second switch circuit respectively comprise a rectifying and filtering module, a transformer, a primary side switch driving module and a signal feedback module, and alternating currents with opposite phases are respectively connected with the input of the first switch circuit and the input of the second switch circuit, are output after being processed by rectifying and filtering, signal feedback and the like in the first switch circuit and the second switch circuit and are connected with two ends of a coil load; the input control circuit comprises a transformer and an offset elimination module, wherein the primary side of the transformer receives a low-frequency signal, and the secondary side outputs a switching signal to switching devices in the first switching circuit and the second switching circuit after the processing of the offset elimination module. The circuit disclosed by the invention has the advantages of simple topology, easiness in realization, reduction in cost, enhancement in driving capability and reduction in influence of direct current bias on coil loads.)

1. A circuit for reliably driving a coil load at a low frequency is characterized by comprising a first switch circuit, a second switch circuit and an input control circuit; the first switch circuit and the second switch circuit respectively comprise a rectifying and filtering module, a transformer, a primary side switch driving module and a signal feedback module, and alternating currents with opposite phases are respectively connected with the input of the first switch circuit and the input of the second switch circuit, and the output of the alternating currents is connected with two ends of a coil load; the input control circuit comprises a transformer and an offset cancellation module, wherein the primary side of the transformer is connected with a low-frequency signal, the secondary side output of the transformer is connected to the input of the offset cancellation module, and the output of the offset cancellation module is connected to the grids of the switching devices in the first switching circuit and the second switching circuit.

2. The circuit for reliably driving a coil load at a low frequency according to claim 1, wherein the first switching circuit comprises a rectifying and filtering module, a first transformer, a primary side switch driving module and a signal feedback module; the input end of the rectification filter module is connected with alternating current, and the output end of the rectification filter module is connected with one end of the primary side of the first transformer; the other end of the primary side of the first transformer is connected with the primary side switch driving module; one end of the secondary side is connected with one end of the coil load, and the other end of the secondary side comprises a first diode, a first MOS tube and a second MOS tube which are connected back to back; the anode of the first diode is connected with the first transformer, and the cathode of the first diode is connected with the drain electrode of the first MOS tube; the source electrode of the second MOS tube is connected with the source electrode of the first MOS tube, the grid electrode of the second MOS tube is connected with the grid electrode of the first MOS tube and is connected with the output of the input control circuit, and the drain electrode of the second MOS tube is grounded; the signal feedback module comprises a voltage division circuit, an adder, a voltage stabilizing source and a photoelectric coupler; one end of the voltage division circuit is connected to one end of the coil load connected with the secondary side of the first transformer, the other end of the voltage division circuit is grounded, and the voltage division end is connected to the inverting input end of the adder; the inverting input end of the adder is also connected to the input control circuit, the non-inverting input end of the adder is grounded, and the output of the adder is connected to the reference electrode of the voltage stabilizing source; the anode of the voltage stabilizing source is grounded, and the cathode of the voltage stabilizing source is connected to the voltage dividing end of the voltage dividing circuit; the anode of the photoelectric coupler is connected to the ungrounded end of the voltage-dividing circuit, the cathode of the photoelectric coupler is connected to the cathode of the voltage-stabilizing source, the emitter of the photoelectric coupler is grounded, and the collector of the photoelectric coupler is connected to the input end of the primary side switch driving module; the primary side switch driving circuit comprises a third MOS tube and a driving circuit; the drain electrode of the third MOS tube is connected with the primary side of the first transformer, the source electrode of the third MOS tube is grounded, and the base electrode of the third MOS tube is connected to the output end of the driving circuit; the input end of the driving circuit is connected to the output end of the signal feedback circuit.

3. The circuit for reliably driving a coil load at a low frequency according to claim 1, wherein the second switching circuit comprises a rectifying and filtering module, a second transformer, a primary side switch driving module, an offset cancellation module and a signal feedback module; the input end of the rectification filter module is connected with the alternating current with the reverse phase of the input end of the first switch circuit, and the output end of the rectification filter module is connected with one end of the primary side of the second transformer; the other end of the primary side of the second transformer is connected with the primary side switch driving module; one end of the secondary side is connected with one end of the coil load, and the other end of the secondary side comprises a second diode, a fourth MOS tube and a fifth MOS tube which are connected back to back; the anode of the second diode is connected with the second transformer, and the cathode of the second diode is connected with the drain electrode of the fourth MOS tube; the source electrode of the fifth MOS tube is connected with the source electrode of the fourth MOS tube, the grid electrode of the fifth MOS tube is connected with the grid electrode of the fourth MOS tube and is connected with the output of the input control circuit, and the drain electrode of the fifth MOS tube is grounded; one end of the voltage division circuit is connected to one end of the coil load connected with the secondary side of the second transformer, the other end of the voltage division circuit is grounded, and the voltage division end is connected to the non-inverting input end of the adder; the non-inverting input end of the adder is also connected to the input control circuit, the inverting input end of the adder is grounded, and the output of the adder is connected to the reference electrode of the voltage stabilizing source; the anode of the voltage stabilizing source is grounded, and the cathode of the voltage stabilizing source is connected to the voltage dividing end of the voltage dividing circuit; the rated anode of the photoelectric coupler is connected to the ungrounded end of the voltage dividing circuit, the cathode of the photoelectric coupler is connected to the cathode of the voltage stabilizing source, the emitter of the photoelectric coupler is grounded, and the collector of the photoelectric coupler is connected to the input end of the primary side switch driving module; the primary side switch driving circuit comprises a sixth MOS tube and a driving circuit; the drain electrode of the sixth MOS tube is connected with the primary side of the second transformer, the source electrode of the sixth MOS tube is grounded, and the base electrode of the sixth MOS tube is connected to the output end of the driving circuit; the input end of the driving circuit is connected to the output end of the signal feedback circuit.

4. The circuit for reliably driving a coil load at a low frequency according to claim 1, wherein said input control circuit comprises a third transformer and an offset cancellation module; the primary side of the third transformer is connected with a low-frequency signal source, the secondary side of the third transformer comprises two windings with different turns, one end of the winding with the small turns is grounded, and the other end of the winding is connected with the input ends of the signal feedback modules in the first switch circuit and the second switch circuit; one end of the winding with a plurality of turns is grounded, and the other end of the winding is connected to the input end of the bias elimination module; the offset cancellation circuit comprises two comparators, an OR gate and an operational amplifier; the non-inverting input end of the first comparator is connected with one end of the third transformer with more secondary windings, the inverting input end of the first comparator is grounded, and the output end of the first comparator is connected with the input end of the OR gate; the non-inverting input end of the second comparator is grounded, the inverting input end of the second comparator is connected with one end of the third transformer with more secondary windings, and the output end of the second comparator is connected with the input end of the OR gate; the non-inverting input end of the operational amplifier is grounded, the inverting input end of the operational amplifier is connected with the output end of the OR gate, and the output end of the operational amplifier is connected with the grids of the first MOS tube, the second MOS tube, the fourth MOS tube and the fifth MOS tube in the first switch circuit and the second switch circuit.

Technical Field

The invention relates to the field of electronic circuits, in particular to a circuit for reliably driving a coil load under low frequency.

Background

In the fields of medical treatment, mine detection, signal emission and the like, an inductive load is generally required to be driven, and energy transmission is carried out by utilizing the basic theory of an electromagnetic field. The existing driving method generally utilizes a switching power supply to perform rectification filtering and alternating current-direct current conversion on alternating current commercial power and then supplies power to a power amplifier, so that an amplified signal drives an inductive load.

The disadvantage of this driving method is that the impedance of the inductive load will increase with the increase of frequency, resulting in the decrease of output current and the reduction of load driving capability, so it is commonly used in low frequency signal, and wastes the wide frequency band of the power amplifier.

Therefore, it is necessary to provide a circuit that reliably drives the coil load at low frequencies.

Disclosure of Invention

In view of the above, the present invention provides a circuit for reliably driving a coil load at low frequencies.

The invention discloses a circuit for reliably driving a coil load under low frequency, which is suitable for occasions using low-frequency signals to drive the coil load. The first switch circuit and the second switch circuit respectively comprise a rectifying and filtering module, a transformer, a primary side switch driving module and a signal feedback module, and alternating currents with opposite phases are respectively connected with the input of the first switch circuit and the input of the second switch circuit, are output after being processed by rectifying and filtering, signal feedback and the like in the first switch circuit and the second switch circuit and are connected with two ends of a coil load; the input control circuit comprises a transformer and an offset elimination module, wherein the primary side of the transformer receives low-frequency signals, and the secondary side outputs switching signals to the switching devices in the first switching circuit and the second switching circuit after the processing of the offset elimination module.

The first switch circuit comprises a rectifying and filtering module, a first transformer, a primary side switch driving module and a signal feedback module. The input end of the rectification filter module is connected with alternating current, and after rectification and filtering of the circuit, pulsating direct current is output and connected with one end of the primary side of the first transformer. The other end of the primary side of the first transformer is connected with the primary side switch driving module; one end of the secondary side is connected with one end of the coil load, and the other end of the secondary side comprises a first diode, a first MOS tube and a second MOS tube which are connected back to back; the anode of the first diode is connected with the first transformer, and the cathode of the first diode is connected with the drain electrode of the first MOS tube; and the source electrode of the second MOS tube is connected with the source electrode of the first MOS tube, the grid electrode of the second MOS tube is connected with the grid electrode of the first MOS tube and is controlled by the output of the input control circuit, and the drain electrode of the second MOS tube is grounded. The signal feedback module comprises a voltage division circuit, an adder, a voltage stabilizing source and a photoelectric coupler; one end of the voltage division circuit is connected to one end of the coil load connected with the secondary side of the first transformer, the other end of the voltage division circuit is grounded, and the voltage division end is connected to the inverting input end of the adder; the inverting input end of the adder is also connected to the input control circuit, the non-inverting input end of the adder is grounded, and the output of the adder is connected to the reference electrode of the voltage stabilizing source; the anode of the voltage stabilizing source is grounded, and the cathode of the voltage stabilizing source is connected to the voltage dividing end of the voltage dividing circuit; the positive pole of the photoelectric coupler is connected to the ungrounded end of the voltage division circuit, the negative pole of the photoelectric coupler is connected to the negative pole of the voltage stabilizing source, the emitting pole of the photoelectric coupler is grounded, and the collecting electrode of the photoelectric coupler is connected to the input end of the primary side switch driving module. The primary side switch driving circuit comprises a third MOS tube and a driving circuit; the drain electrode of the third MOS tube is connected with the primary side of the first transformer, the source electrode of the third MOS tube is grounded, and the base electrode of the third MOS tube is connected to the output end of the driving circuit; the input end of the driving circuit is connected to the output end of the signal feedback circuit.

The second switch circuit comprises a rectifying and filtering module, a second transformer, a primary side switch driving module, a bias eliminating module and a signal feedback module. The input end of the rectification filter module is connected with the alternating current with the phase opposite to the input end of the first switch circuit, and after rectification and filtering of the circuit, pulsating direct current is output and is electrically connected with one end of the primary side of the second transformer. The other end of the primary side of the second transformer is connected with the primary side switch driving module; one end of the secondary side is connected with one end of the coil load, and the other end of the secondary side comprises a second diode, a fourth MOS tube and a fifth MOS tube which are connected back to back; the anode of the second diode is connected with the second transformer, and the cathode of the second diode is connected with the drain electrode of the fourth MOS tube; and the source electrode of the fifth MOS tube is connected with the source electrode of the fourth MOS tube, the grid electrode of the fifth MOS tube is connected with the grid electrode of the fourth MOS tube and is controlled by the output of the input control circuit, and the drain electrode of the fifth MOS tube is grounded. One end of the voltage division circuit is connected to one end of the coil load connected with the secondary side of the second transformer, the other end of the voltage division circuit is grounded, and the voltage division end is connected to the non-inverting input end of the adder; the non-inverting input end of the adder is also connected to the input control circuit, the inverting input end of the adder is grounded, and the output of the adder is connected to the reference electrode of the voltage stabilizing source; the anode of the voltage stabilizing source is grounded, and the cathode of the voltage stabilizing source is connected to the voltage dividing end of the voltage dividing circuit; the rated anode of the photoelectric coupler is connected to the ungrounded end of the voltage dividing circuit, the cathode of the photoelectric coupler is connected to the cathode of the voltage stabilizing source, the emitter of the photoelectric coupler is grounded, and the collector of the photoelectric coupler is connected to the input end of the primary side switch driving module. The primary side switch driving circuit comprises a sixth MOS tube and a driving circuit; the drain electrode of the sixth MOS tube is connected with the primary side of the second transformer, the source electrode of the sixth MOS tube is grounded, and the base electrode of the sixth MOS tube is connected to the output end of the driving circuit; the input end of the driving circuit is connected to the output end of the signal feedback circuit.

The input control circuit includes a third transformer and an offset cancellation module. The primary side of the third transformer is connected with a low-frequency signal source, the secondary side of the third transformer comprises two windings with different turns, one end of the winding with the small number of turns is grounded, and the other end of the winding is connected with the input ends of the signal feedback modules in the first switch circuit and the second switch circuit; and one end of the winding with a large number of turns is grounded, and the other end of the winding is connected to the input end of the bias elimination module. The offset cancellation circuit comprises two comparators, an OR gate and an operational amplifier; the non-inverting input end of the first comparator is connected with one end of the third transformer with more secondary windings, the inverting input end of the first comparator is grounded, and the output end of the first comparator is connected with the input end of the OR gate; the non-inverting input end of the second comparator is grounded, the inverting input end of the second comparator is connected with one end of the third transformer with more secondary windings, and the output end of the second comparator is connected with the input end of the OR gate; the non-inverting input end of the operational amplifier is grounded, the inverting input end of the operational amplifier is connected with the output end of the OR gate, and the output end of the operational amplifier is connected with the grids of the first MOS tube, the second MOS tube, the fourth MOS tube and the fifth MOS tube in the first switch circuit and the second switch circuit.

The circuit disclosed by the invention has the advantages of simple topology, easiness in realization, reduced cost, enhanced driving capability, reduced influence of direct current bias on coil loads and reduced heat productivity of the loads.

In order to make the aforementioned and other objects of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a block diagram of the connections of a circuit for reliably driving a coil load at low frequencies in accordance with the present invention;

fig. 2 is a first embodiment of a circuit for reliably driving a coil load at low frequencies according to the present invention.

Numbering in the figures:

10: a first switching circuit; 20: a second switching circuit; 30: an input control circuit;

110: a rectification filter module in the first switch circuit;

210: a rectification filter module in the second switch circuit;

310: an offset cancellation module in the input control circuit.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention.

Fig. 1 is a connection block diagram of a circuit for reliably driving a coil load at a low frequency according to the present invention, which includes a first switch circuit 10, a second switch circuit 20, and an input control circuit 30. The input ends of the first switch circuit 10 and the second switch circuit 20 are respectively connected with alternating current with opposite phases, and the alternating current is processed by the internal module and then output to be connected with the coil load. The input end of the input control circuit 30 is connected to a low frequency signal source, and the output control signals processed by the internal modules are respectively connected to corresponding modules in the first switch circuit 10 and the second switch circuit 20.

Referring to fig. 2, a circuit diagram of a circuit for driving a coil load reliably at low frequency according to a first embodiment of the present invention includes a first switch circuit 10, a second switch circuit 20, and an input control circuit 30. The first switch circuit 10 comprises a primary side switch driving module consisting of a rectifying filter circuit 110, a first transformer T1, a driving circuit U3 and a third MOS tube M3, and a signal feedback module consisting of voltage division circuits R1 and R2, an adder A1, a voltage stabilizing source D3 and a photoelectric coupler U1; the input end of the rectifying and filtering module 110 is connected with the alternating current, and the output end is connected with one end of the primary side of the T1. The other end of the primary side of the T1 is connected with the drain electrode of the M3, one end of the secondary side is connected with one end of the coil load, and the other end of the secondary side is connected with the anode of a first diode D1; the negative electrode of the D1 is connected with the drain electrode of the M1; the source of M2 is connected with the source of M1, the gate is connected with the gate of M1, controlled by the input control circuit 30, and the drain is grounded; one end of the R1 in the voltage division circuit is connected to one end of the T1 connected with the coil load, the other end is a voltage division end, and the voltage division end is connected with the R2 in series to the ground; the inverting input end of the adder A1 is connected with the voltage dividing end of the voltage dividing circuit and is also connected to the input control circuit 30, the non-inverting input end is grounded, and the output is connected to the reference pole of D3; the anode of D3 is grounded, and the cathode is connected to the voltage dividing end; the anode of U1 is connected to R1 and to the end of T1 connected to the coil load, the cathode is connected to the cathode of D3, the emitter is grounded, and the collector is connected to the input end of U3; the source of M3 is connected to ground, and the base is connected to the output of U3. The second switch circuit 20 comprises a primary side switch driving module consisting of a rectifying filter circuit 210, a second transformer T2, a driving circuit U4 and a sixth MOS tube M6, and a signal feedback module consisting of voltage division circuits R3 and R4, an adder A21, a voltage stabilizing source D4 and a photoelectric coupler U2; the input end of the rectifying and filtering module 210 is connected with alternating current, and the output end is connected with one end of the primary side of T2; the other end of the primary side of the T2 is connected with the drain electrode of the M6, one end of the secondary side is connected with one end of the coil load, and the other end of the secondary side is connected with the anode of a second diode D2; the cathode of D2 is connected to the drain of M4. The source of M5 is connected with the source of M4, the gate is connected with the gate of M4, controlled by the input control circuit 30, and the drain is grounded; one end of the R3 in the voltage division circuit is connected to one end of the T2 connected with the coil load, the other end is a voltage division end, and the voltage division end is connected with the R4 in series to the ground; the inverting input end of the adder A2 is connected with the voltage dividing end of the voltage dividing circuit and is also connected to the input control circuit 30, the non-inverting input end is grounded, and the output is connected to the reference pole of D4; the anode of D4 is grounded, and the cathode is connected to the voltage dividing end; the anode of U2 is connected to R3 and to the end of T2 connected to the coil load, the cathode is connected to the cathode of D4, the emitter is grounded, and the collector is connected to the input end of U4; the source of M6 is connected to ground, and the base is connected to the output of U4. The input control circuit 30 includes a third transformer T3 and an offset cancellation module 310; the primary side of the T3 is connected with a low-frequency signal source, and the secondary side comprises a winding Ns1 with many turns and a winding Ns2 with few turns; one end of Ns2 is grounded, and the other end is connected with the inverting input end of A1 and the non-inverting input end of A2; ns1 has one end connected to ground and the other end connected to the input of offset cancellation block 310; the offset cancellation circuit 310 comprises comparators A3 and A4, an OR gate U5 and an operational amplifier A5; the non-inverting input end of A3 and the inverting input end of A4 are both connected to the end of Ns2 which is not grounded, the inverting input end of A3 and the non-inverting input end of A4 are both grounded, and the output ends of A3 and A4 are both connected to the input end of U5; the non-inverting input end of A5 is grounded, the inverting input end is connected to the output end of U5, and the output is connected to the gates of M1, M2, M3 and M4.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes performed by the present specification and drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.