TW201804720A - Boosting conversion circuit capable of sensing inductor current enables engineers to directly understand variation of the inductive current trough the sensing current signal - Google Patents

Abstract

A boosting conversion circuit capable of sensing inductor current comprises an inductor connected to a power supply source, an active switch, a passive switch connected to the active switch, a capacitor connected to an end of the passive switch without connecting to one end of the active switch, a center tap current ratio element and a signal rectification unit connected to the center tap current ratio element. The center tap current ratio element comprises a primary winding set and a secondary winding set. Two ends of the primary winding set are respectively connected to the active switch and the passive switch and are connected to the inductor through a tap end. The secondary winding set generates magnetic induction to obtain a magnetic induction signal when the primary winding set receives the inductive current. The signal rectification unit is connected to the secondary winding set to receive the magnetic induction signal and to generate a sensing current signal corresponding to the inductive current.

Description

Boost converter circuit capable of sensing inductor current

The present invention relates to a step-up conversion circuit, in particular to a step-up conversion circuit including a center-tapped specific-current element to sense an inductor current.

With the development of the electronics industry, in addition to the original functions, many circuits require more stable control of the circuit. Among them, the boost converter circuit is related to the current of the inductor in the boost converter circuit. Practitioners use Hall elements to measure and connect Hall elements and inductors in series to obtain inductor current. However, Hall elements are generally large in size and occupy more wiring space, which is not conducive to the miniaturization of today's electronic equipment. And the cost of the Hall element is higher, which will increase the cost of the overall circuit.

In addition to the above embodiments, the US Pat. No. 9,325,235 discloses another implementation manner. As can be known from the specification of FIG. 4, this implementation manner is connected in series with a ratio-current element near an end of an active switch of an active switch. The current element senses current. However, the active switch in the boost conversion circuit is turned on or off by the control of a driving signal. When the active switch is turned on, the circuit to which the active switch belongs will form a path, so that the current can flow through the ratio normally. Stream the component to get a sensed signal. However, when the active switch is turned off, the circuit to which the active switch belongs will form an open circuit, so that the current cannot flow through the specific-current element, and the specific-current element cannot obtain the sensing signal. In this way, the specific current component can only sense the current when the active switch is on, and cannot sense the inductor current.

The main purpose of the present invention is to solve the problems of conventional installation of a large Hall element if the inductor current needs to be sensed in its entirety, which leads to rising costs and limited placement of electronic components.

Another object of the present invention is to solve the problem that although a current-sharing element is connected in series to an active switch, the current-sharing element will not be able to fully sense the current of the inductor because the active switch is turned on or off.

To achieve the above object, the present invention provides a step-up conversion circuit capable of sensing an inductor current, including an inductor connected to a power supply source, an active switch, a passive switch connected to the active switch, and a connection to the active switch. The capacitor at one end of the passive switch is not connected to the active switch, a center-tapped specific-current element and a signal rectification unit connected to the center-tapped specific-current element. The center-tap specific current element includes a primary winding and a primary winding. The primary winding has two ends connected to the active switch and the passive switch respectively, and is connected to the inductor by a tap end, and the secondary winding is connected to the primary winding. When the winding receives the inductance current, it generates magnetic induction with the primary winding to obtain a magnetic induction signal. The signal rectifying unit is connected to the secondary winding, receives the magnetic induction signal and rectifies to generate a sensed current signal corresponding to the inductor current.

In one embodiment, the signal rectification unit is a full-wave rectification architecture or a half-wave rectification architecture.

In one embodiment, the power supply source is a DC power source.

In one embodiment, the power supply source is an AC power source, and the boost conversion circuit further includes a full-bridge rectifier unit connected between the power supply source and the inductor.

In one embodiment, the passive switch has a forward-conducting terminal connected to the center-tap specific-flow element and a reverse-cutting terminal connected to the capacitor.

In one embodiment, the boost conversion circuit includes a conversion resistor disposed between the center-tapped specific-current element and the signal rectifying unit, and the conversion resistor is more in parallel with the secondary winding.

In one embodiment, the boost conversion circuit includes a voltage regulating resistor connected to the signal rectifying unit to receive the detection current signal.

In one embodiment, the active switch is a transistor, a metal oxide semiconductor field effect transistor or an insulated gate bipolar transistor.

Through the foregoing disclosed embodiments of the present invention, compared with conventional methods, the present invention has the following characteristics: The present invention allows the center-tapped specific-current element to be disposed between the inductor, the active switch, and the passive switch. The active state of the active switch can accept the inductor current, and can completely generate the magnetic induction signal. The magnetic induction signal is rectified to form the perceived current signal. The perceived current signal corresponds to the inductor current, and The engineer can directly understand the change of the inductor current by the sensed current signal. In addition, the present invention is implemented with the center-tap specific flow element, which can specifically solve the problems of excessive element volume and rising cost caused by the conventional Hall element implementation.

The detailed description and technical contents of the present invention are described below with reference to the drawings:

Referring to FIG. 1, the present invention provides a boost conversion circuit 1 capable of sensing an inductor current. The boost conversion circuit 1 is connected to a power supply source 2 to obtain a working power from the power supply source 2 and to perform the operation on the work. Electricity undergoes boost conversion. Herein, the power supply source 2 is described as a direct current power source, but it is not limited thereto. In this embodiment, the boost conversion circuit 1 has an inductor 11 connected to the power supply source 2, an active switch 12, a passive switch 13 connected to the active switch 12, and one connected to the passive The capacitor 14 at one end of the switch 13 is not connected to the active switch 12, a center-tap specific current element 15 and a signal rectifying unit 16. The inductor 11 generates an inductor current 110 when the working power is input to the boost conversion circuit 1. The active switch 12 may be a transistor (BJT), a metal oxide semiconductor field effect transistor (MOSFET), or an insulated gate bipolar transistor (IGBT). The active switch 12 is provided by a driving unit ( (Not shown in the figure) accepts a driving signal, and is controlled by the driving signal to switch between on and off states, and the boost conversion circuit 1 determines the degree of boost conversion of the working power according to the duty cycle of the driving signal . In addition, the passive switch 13 is a diode, which has a forward conducting terminal 131 connected to the center-tap specific-flow element 15 and a reverse blocking terminal 132 connected to the capacitor 14.

The center-tap specific current element 15 includes a primary winding 151 and a primary winding 152. The primary winding 151 includes a first sub-winding 153, a second sub-winding 154, and a first sub-winding 153 and the first sub-winding 153. The second sub-winding 154 is connected to the tap end 155. The center-tap specific current element 15 is connected to the inductor 11, the active switch 12 and the passive switch 13 through the primary winding 151. More specifically, the primary winding 151 is connected to the passive switch through the first sub-winding 153. 13. Connect the active switch 12 with the second sub-winding 154, and connect the inductor 11 with the tap end 155. In addition, when the primary winding 151 receives the inductor current 110, the secondary winding 152 generates magnetic induction with the primary winding 151 to obtain a magnetic induction signal 150. Furthermore, the signal rectifying unit 16 is connected to the secondary winding 152 and receives the magnetic induction signal 150 to rectify and generate a sensed current signal 160 corresponding to the inductor current 110. Further, the signal rectification unit 16 may be a half-wave rectification structure or a full-wave rectification structure. The half-wave rectification structure is shown in FIG. 1 and the full-wave rectification structure is shown in FIG. 2.

As mentioned above, the implementation principle of the boost conversion circuit 1 of the present invention still belongs to the notification technology in this field, and will not be repeated here. During the implementation of the present invention, the active switch 12 will be controlled by the driving signal to switch on or off. When the active switch 12 is turned on, the inductor current 110 will flow to the active switch 12 through the second sub-winding 154 of the primary winding 151. At this time, the second sub-winding 154 generates magnetic induction with the secondary winding 152 due to the inductance current 110 flowing, so that the secondary winding 152 generates the magnetic induction signal 150. On the other hand, when the active switch 12 is turned off, the branch to which the active switch 12 belongs will be opened, so that the inductor current 110 flows to the passive switch 13 through the first sub-winding 153 of the primary winding 151. At this time, the first sub-winding 153 will generate magnetic induction with the primary winding 151 due to the inductance current 110 flowing, so that the secondary winding 152 will generate the magnetic induction signal 150. It can be known that the center-tap specific current element 15 of the present invention can generate the magnetic induction signal 150 regardless of whether the active switch 12 is turned on or not, so that the magnetic induction signal 150 can completely present the inductor current 110 in the existing The source switch 12 is continuously changed between on and off.

In addition, here is a circuit simulation using the embodiment disclosed in FIG. 1. The waveforms of the inductor current 110, the magnetic induction signal 150, and the perceived current signal 160 are as shown in FIG. 3. The waveforms shown in FIG. 3 can be directly understood. The waveform of the sensed current signal 160 is equal to the waveform of the inductor current 110. Therefore, the relevant parameters of the inductor current 110 can be understood by the sensed current signal 160.

Please refer to FIG. 4. In this embodiment, the power supply source 2 is further an AC power source, and the boost conversion circuit 1 further includes a full-bridge type connected between the power supply source 2 and the inductor 11. A rectifier unit 17. The full-bridge rectifier unit 17 can convert the AC power provided by the power supply source 2 into DC power for subsequent circuit use. However, the implementation process of this embodiment is the same as that of the previously disclosed embodiment, and details are not described herein again. In addition, the signal rectification unit 16 included in the boost conversion circuit 1 in this embodiment may also be implemented in a half-wave rectification architecture or a full-wave rectification architecture. The half-wave rectification architecture is shown in FIG. 4. The full-wave rectification architecture is as shown in FIG. 5. In addition, the circuit simulation is performed according to the embodiment disclosed in FIG. 4. The waveforms of the inductor current 110, the magnetic induction signal 150 and the perceived current signal 160 are as shown in FIG. 6. The waveforms shown in FIG. 6 can be directly understood. The waveform of the perceived current signal 160 is equal to the waveform of the inductor current 110, and the waveform of the inductor current 110 can be obtained by the perceived current signal 160.

Please refer to FIG. 3 again. In an embodiment, the boost conversion circuit 1 further includes a conversion resistor 180 disposed between the center-tap specific current element 15 and the signal rectifying unit 16. The conversion resistor 180 and the secondary resistor The stage windings 152 are more parallel. The conversion resistor 180 changes the characteristics of the magnetic induction signal 150 so that the current of the magnetic induction signal 150 is obvious, so that the magnetic induction signal 150 can be reliably used by the signal rectifying unit 16. Further, the signal rectifying unit 16 can output the sensed current signal 160 to a microcontroller, but in order to make the voltage of the sensed current signal 160 conform to the use of the microcontroller. In an embodiment, the boost conversion circuit 1 further includes a voltage regulating resistor 181 connected to the signal rectifying unit 16 to receive the sensed current signal 160.

The present invention has been described in detail above, but the above is only one of the preferred embodiments of the present invention. When the scope of implementation of the present invention cannot be limited by this, that is, the equality made according to the scope of patent application of the present invention Changes and modifications should still be covered by the patent of the present invention.

1‧‧‧Boost conversion circuit
11‧‧‧Inductance
110‧‧‧Inductive current
12‧‧‧ Active Switch
13‧‧‧ Passive Switch
131‧‧‧Front end
132‧‧‧ reverse cut-off
14‧‧‧Capacitor
15‧‧‧ Center Tap Specific Flow Element
150‧‧‧ Magnetic signal
151‧‧‧Primary winding
152‧‧‧ secondary winding
153‧‧‧first subwinding
154‧‧‧Second Sub Winding
155‧‧‧Tap end
16‧‧‧Signal Rectifier Unit
160‧‧‧Sense current signal
17‧‧‧Full bridge rectifier unit
180‧‧‧ Conversion resistor
181‧‧‧ voltage regulating resistor
2‧‧‧ Electricity supply source

FIG. 1 is a schematic circuit diagram of a first embodiment of the present invention. FIG. 2 is a schematic circuit diagram of a second embodiment of the present invention. FIG. 3 is a circuit simulation waveform diagram of the first embodiment of the present invention. FIG. 4 is a schematic circuit diagram of a third embodiment of the present invention. FIG. 5 is a schematic circuit diagram of a fourth embodiment of the present invention. FIG. 6 is a circuit simulation waveform diagram of the second embodiment of the present invention.

1‧‧‧Boost conversion circuit

11‧‧‧Inductance

110‧‧‧Inductive current

12‧‧‧ Active Switch

13‧‧‧ Passive Switch

14‧‧‧Capacitor

15‧‧‧ Center Tap Specific Flow Element

150‧‧‧ Magnetic signal

151‧‧‧Primary winding

152‧‧‧ secondary winding

153‧‧‧first subwinding

154‧‧‧Second Sub Winding

155‧‧‧Tap end

16‧‧‧Signal Rectifier Unit

160‧‧‧Sense current signal

180‧‧‧ Conversion resistor

181‧‧‧ voltage regulating resistor

2‧‧‧ Electricity supply source

Claims (8)

A boost conversion circuit capable of sensing an inductor current includes: an inductor connected to a power supply source; an active switch and a passive switch connected to the active switch; a capacitor connected to the passive switch and The active switch is connected to one end; a center-tap specific current component includes a primary winding and a primary winding, and the active winding and the passive switch are respectively connected to both ends of the primary winding, and are connected to the inductor through a tap end. The secondary winding obtains a magnetic induction signal when the primary winding receives the inductive current and generates magnetic induction with the primary winding; and a signal rectifying unit is connected to the secondary winding, receives the magnetic induction signal and rectifies the generated signal. A sensed current signal corresponding to the inductor current. The boost conversion circuit capable of sensing the inductor current according to claim 1, wherein the signal rectification unit is a full-wave rectification structure or a half-wave rectification structure. The boost conversion circuit capable of sensing an inductor current according to claim 1 or 2, wherein the power supply source is a direct current power source. The boost conversion circuit capable of sensing the inductor current according to claim 1, wherein the power supply source is an AC power source, and the boost conversion circuit further includes a full bridge connected between the power supply source and the inductor. Rectifier unit. The step-up conversion circuit capable of sensing inductor current according to claim 1 or 2 or 4, wherein the passive switch has a forward terminal connected to the center-tap current-sharing element and a reverse cut-off connected to the capacitor. end. The step-up conversion circuit capable of sensing the inductor current according to claim 1 or 2, wherein the step-up conversion circuit includes a conversion resistor disposed between the center-tap specific-current element and the signal rectifying unit, and the conversion resistor and This secondary winding is more parallel. The boost conversion circuit capable of sensing the inductor current according to claim 6, wherein the boost conversion circuit includes a voltage regulating resistor connected to the signal rectifying unit to receive the sensed current signal. The boost conversion circuit capable of sensing the inductor current according to claim 1 or 2, wherein the active switch is a transistor, a metal oxide semiconductor field effect transistor or an insulated gate bipolar transistor.