TWI427914B - Voltage converting apparatus - Google Patents

Description

Voltage conversion device

The present invention relates to a voltage conversion device, and more particularly to a drive current adjustment mechanism for an AC to DC voltage conversion device.

Please refer to FIG. 1A and FIG. 1B for circuit diagrams of conventional resistive and capacitive AC DC voltage converters 110 and 120, respectively. Wherein, in the AC DC voltage converter 110, the AC input voltage ACIN is rectified by the diode D1, and after the resistor R1 and the Zener diode ZD1 (zener diode) and the capacitor C1 function as a voltage stabilization function, a DC output is generated. The voltage drives the load 111. In the AC DC voltage converter 120, the AC input voltage ACIN is first passed through the AC coupling capacitor C1, and then passed through the Zener diode ZD1, the capacitor C1, and the diode D1 for voltage regulation and rectification, respectively. The DC output voltage is generated to drive the load 121.

In the above two types of AC DC voltage converters 110 and 120, the outputs of the AC DC voltage converters 110 and 120 are not changed correspondingly when the loads 111 and 121 are in the operation mode or in the standby mode. Drive current I. When the loads 111 and 121 are in the standby mode, the required driving current is obviously smaller than the driving current I of the fixed output of the AC-DC voltage converters 110 and 120. In this case, when the loads 111 and 121 are in the standby mode, excess current is discharged from the Zener diode ZD1 and was wasted.

The invention provides a voltage conversion device for changing the current provided by the voltage conversion device according to the current demand state of the driven load device, so as to effectively save power consumption.

The invention provides a voltage conversion device for receiving an AC input voltage and generating a DC output voltage according to the converted AC input voltage to drive the load device. The voltage conversion device includes a rectifier, a current path selector, and a load state detector. The rectifier receives the AC input voltage and accordingly generates a DC input voltage. The current path selector has an input end and an output end, the input end of which receives a DC input voltage, and the output end of which generates a DC output voltage. The current path selector includes first and second current transfer paths connected in series between the input and output of the current path selector. The current path selector selects at least one of the first and second current transmission paths to transmit the DC input voltage to the output of the current path selector according to the selection signal, thereby changing the input end and the output end of the current path selector Equivalent impedance between. The load state detector is coupled to the output of the current path selector and the load device to generate a selection signal according to the current demand state of the detected load device.

In an embodiment of the invention, the load status detector includes a control unit. The control unit is coupled to the output of the current path selector and the load device, and the control unit receives and generates a selection signal according to the mode setting signal.

In an embodiment of the invention, the control unit further generates a load setting signal according to the mode setting signal. The control unit receives and controls the current demand state of the load device according to the mode setting signal.

In an embodiment of the invention, the load state detector includes a current detecting circuit, a control unit, and a logic operation circuit. The current detecting circuit is coupled to the output end of the current path selector for detecting the output current of the current path selector, and generating a detection result signal according to the output current. The control unit is coupled to the current detecting circuit and the load device, and receives the mode setting signal to generate a mode setting result. The logic operation circuit is coupled to the current detection circuit, the control unit and the current path selector, and receives and performs a logic operation according to the detection result signal and the mode setting result to generate a selection signal.

In an embodiment of the invention, the current detecting circuit includes a comparator, a sensing resistor, and a threshold voltage source. The output of the comparator generates a detection result signal. The sense resistor is connected in series between the first input of the comparator and the output of the current path selector. A threshold voltage source is connected in series between the second input of the comparator and the output of the current path selector to provide a threshold voltage.

In an embodiment of the invention, the logical operation unit is an OR gate. The input of the OR gate receives the detection result signal and the mode setting result, and generates a selection signal at its output.

In an embodiment of the invention, the load state detector includes a current detecting circuit. The current detecting circuit is coupled to the output of the current path selector for detecting the output current of the current path selector and generating a selection signal according to the output current.

In an embodiment of the invention, the load status detector further includes a control unit. The control unit is coupled to the current detecting circuit and the load device, and receives and controls the current demand state of the load device according to the mode setting signal.

In an embodiment of the invention, a voltage stabilizing circuit is further included. The voltage stabilizing circuit is coupled to the output of the current path selector for stabilizing the voltage value of the DC output voltage.

In an embodiment of the invention, the voltage stabilizing circuit includes a Zener diode and a voltage stabilizing capacitor. The Zener diode is connected in series between the output of the current path selector and the ground voltage. The Zener capacitor is coupled in parallel with the Zener diode.

In an embodiment of the invention, the current path selector further includes a selection switch. One end of the selection switch receives the DC input voltage and the first end of the first current transmission path, and the other end of the selection switch is coupled to the first end of the second current transmission path. The selector switch receives the selection signal to turn on or off. The second ends of the first and second current transmission paths are coupled to the output of the current path selector.

In an embodiment of the invention, the first current transmission path provides an equivalent impedance greater than the equivalent impedance provided by the second current transmission path.

In an embodiment of the invention, the current path selector further includes a selection switch. One end of the selection switch receives the DC input voltage, and the other end of the selection switch is coupled to the first end of the first current transmission path or the first end of the second current transmission path according to the selection signal. The second ends of the first and second current transmission paths are coupled to the output of the current path selector, and the first current transmission path provides an equivalent impedance greater than the equivalent impedance provided by the second current transmission path.

In an embodiment of the invention, the current demand state is the current consumed by the load device when the load device is turned on or off.

Based on the above, the present invention transmits a DC input voltage rectified by a rectifier by providing current transmission paths of different impedances, and thereby generates DC output voltages having different driving capabilities to drive load devices in different current demand states. In this way, efficiency can be effectively improved to meet the demand for green energy.

The above described features and advantages of the present invention will be more apparent from the following description.

Referring to FIG. 2, FIG. 2 is a schematic diagram of a voltage conversion device 200 according to an embodiment of the present invention. The voltage conversion device 200 includes a rectifier 210, a current path selector 220, a load state detector 230, and a voltage stabilization circuit 240. The voltage conversion device 200 receives the AC input voltage ACVIN and generates a DC output voltage DCVOUT according to the converted AC input voltage ACVIN to drive the load device 250.

The rectifier 210 receives the AC input voltage ACVIN, and the rectifier 210 rectifies the AC input voltage ACVIN to produce a DC input voltage DCVIN. In the present embodiment, the rectifier 210 is a half-wave rectifier constructed using a diode. That is to say, in the present embodiment, the DC input voltage DCVIN is generated by the rectifier 210 by filtering out the voltage of the negative half cycle of the AC input voltage ACVIN.

The current path selector 220 has an input terminal P1 and an output terminal P2. The input terminal P1 of the current path selector 220 is coupled to the rectifier 210 to receive the DC input voltage DCVIN, and the output terminal P2 of the current path selector 220 generates the DC output voltage DCVOUT. The current path selector 220 includes two current transmission paths 221 and 222. The current transmission paths 221 and 222 are coupled in series between the input terminal P1 and the output terminal P2 of the current path selector 220. The current path selector 220 further receives the selection signal SEL and selects at least one of the current transmission paths 221 and 222 to transmit the DC input voltage DCVIN to the output terminal P2 of the current path selector 220 according to the selection signal SEL and thereby generate DC output voltage DCVOUT. Wherein, when the current path selector 220 changes the transmission path of the DC input voltage DCVIN according to the selection signal SEL, the equivalent impedance between the input terminal P1 and the output terminal P2 of the current path selector 220 also changes.

In the embodiment, the current path selector 220 further includes a selection switch SW1. The selection switch SW1 is controlled to be turned on or off by the selection signal SEL. One end of the selection switch SW1 is coupled to the input terminal P1 of the current path selector 220 to receive the DC input voltage DCVIN, and the other end is coupled to the current transmission path 222. The current transmission path 221 is connected across the input terminal P1 of the current path selector 220 and the second terminal of the current transmission path 222. When the selection switch SW1 is turned off in accordance with the selection signal SEL, the DC input voltage DCVIN is received by the current transmission path 221 and transmitted to the output terminal P2 of the current path selector 220 and generates a DC output voltage DCVOUT. When the selection switch SW1 is turned on according to the selection signal SEL, the DC input voltage DCVIN is simultaneously transmitted by the current transmission paths 221 and 222.

It should be noted here that the current transmission paths 221 and 222 respectively provide an equivalent impedance, and the equivalent impedance provided by the current transmission path 221 is greater than the equivalent impedance provided by the current transmission path 222. When the DC input voltage DCVIN is only transmitted by the current transmission path 221 (when the selection switch SW1 is turned off), the equivalent impedance between the input terminal P1 and the output terminal P2 of the current path selector 220 is equal to that provided by the current transmission path 221, etc. Effective impedance. When the DC input voltage DCVIN is simultaneously transmitted by the current transmission paths 221 and 222 (when the selection switch SW1 is turned on), the equivalent impedance between the input terminal P1 and the output terminal P2 of the current path selector 220 is equal to the current transmission paths 221 and 222. The equivalent impedance is provided in parallel with the impedance value. That is to say, the equivalent impedance between the input terminal P1 and the output terminal P2 of the current path selector 220 when the selection switch SW1 is turned off is greater than the input terminal P1 and the output terminal P2 of the current path selector 220 when the selection switch SW1 is turned on. Equivalent impedance.

The load state detector 230 is coupled to the output P2 of the current path selector 220 and the load device 250. The load status detector 230 detects the current demand status of the load device 250 and accordingly generates a selection signal SEL. In the present embodiment, the load status detector 230 includes a control unit 231. The control unit 231 receives the mode setting signal MODSET and learns the current demand state of the load device 250 according to the mode setting signal MODSET. The mode setting signal MODSET is a signal input from the outside to indicate that the setting load device 250 enters the operation mode or the standby mode. When the mode setting signal MODSET indicates that the load device 250 enters the working mode, it indicates that the current demand state of the load device 250 requires a large driving current. At this time, the control unit 231 generates the selection signal SEL according to the mode setting signal MODSET to turn on the selection switch SW1 to select a transmission path of a smaller equivalent impedance to transmit the DC input voltage DCVIN. And, the control unit 231 generates a load setting signal LS according to the mode setting signal MODSET to activate the load device 250 to put the load device 250 into the operating mode.

In contrast, when the mode setting signal MODSET indicates that the load device 250 enters the standby mode, it indicates that the current demand state of the load device 250 requires a smaller drive current. At this time, the control unit 231 generates the selection signal SEL according to the mode setting signal MODSET to turn off the selection switch SW1 to select a transmission path of a larger equivalent impedance to transmit the DC input voltage DCVIN. And, the control unit 231 generates the load setting signal LS according to the mode setting signal MODSET to turn off the load device 250, and causes the load device 250 to enter the standby mode.

The voltage stabilizing circuit 240 is coupled to the output terminal P2 of the current path selector 220 for stabilizing the voltage value of the DC output voltage DCVOUT on the output terminal P2 of the current path selector 220. In this embodiment, the voltage stabilizing circuit 240 includes a Zener diode ZD1 and a voltage stabilizing capacitor C2. The Zener diode ZD1 is connected in series between the output terminal P2 of the current path selector 220 and the ground voltage GND, and the voltage stabilizing capacitor C2 is coupled in parallel with the Zener diode ZD1. The Zener diode ZD1 is used to make the DC output voltage DCVOUT pre-set at a certain voltage (the breakdown voltage of the Zener diode ZD1), and the Zener capacitor C2 can effectively reduce the ripple of the DC output voltage DCVOUT ( Ripple) degree.

Referring to FIG. 3, FIG. 3 is a schematic diagram of a voltage conversion device 300 according to another embodiment of the present invention. The voltage conversion device 300 includes a rectifier 310, a current path selector 320, a load state detector 330, and a voltage stabilization circuit 340. The voltage conversion device 300 receives the AC input voltage ACVIN and generates a DC output voltage DCVOUT to drive the load device 350 in accordance with the converted AC input voltage ACVIN.

Different from the previous embodiment, the load state detector 330 in this embodiment includes a control unit 331 and a current detecting circuit 332. The current detecting circuit 332 is coupled to the output of the current path selector 320 for detecting the output current of the current path selector 320 and generating the selection signal SEL according to the detected output current. The control unit 331 is coupled to the current detecting circuit 332 and the load device 350 for receiving and turning on or off the load device 350 according to the mode setting signal MODSET.

Please note that in the present embodiment, the selection signal SEL is used by the current detecting circuit 332 to detect the current flowing to the load device 350 to know the current demand state of the load device 350. The selection signal SEL is generated according to the current demand state of the load device 350 to change the magnitude of the drive current provided by the voltage conversion device 300. That is, the voltage conversion device 300 can actively detect that the load device 350 is in the standby mode or the operation mode, and adjust the transmission selection path of the DC input voltage generated thereby to adjust the voltage conversion device 300. The amount of drive current.

Referring to FIG. 4A, FIG. 4A is a schematic diagram of a voltage conversion device 400 according to still another embodiment of the present invention. The voltage conversion device 400 includes a rectifier 410, a current path selector 420, a load state detector 430, and a voltage stabilization circuit 440. The voltage conversion device 400 receives the AC input voltage ACVIN and generates a DC output voltage DCVOUT to drive the load device 450 according to the converted AC input voltage ACVIN.

Different from the foregoing embodiment, the load state detector 430 in this embodiment includes a control unit 431, a current detecting circuit 432, and a logical operation unit constructed by the OR gate OR1. The current detecting circuit 432 is coupled to the output of the current path selector 420 for detecting the output current of the current path selector 420 and generating the detection result signal DR according to the detected output current. The control unit 431 is coupled to the current detecting circuit 432 and the load device 435, and receives the mode setting signal MODSET to generate the mode setting result MR. The input terminal of the OR gate OR1 of the logic operation unit receives the detection result signal DR and the mode setting result MR, and performs a logic operation on the detection result signal DR and the mode setting result MR to generate the selection signal SEL.

That is, in the embodiment of FIG. 4A, the load state detector 430 sets the selection signal in addition to the detection result signal DR obtained by the current demand state of the load device 450 actively detected by the current detecting circuit 432. In addition to the SEL, the selection signal SEL can also be set by the control unit 431 according to the mode setting result MR generated by the mode setting signal MODSET. As a practical example, when the load device 450 enters the working mode, the current detecting circuit 432 detects that the load device 450 needs a large driving current and generates a logic high level detection result signal DR. The OR gate OR1 generates a logic high level selection signal SEL according to the logic high level detection result signal DR to turn on the selection switch SW1, and causes the voltage conversion device 400 to provide a higher driving current. Alternatively, when the load device 450 enters the working mode, the control unit 431 generates a logic high level through the OR gate OR1 according to the mode setting result MR of the logic high level generated by the setting mode device 450 entering the mode setting signal MODSET of the operating mode. The selection signal SEL turns on the selection switch SW1 and causes the voltage conversion device 400 to provide a higher drive current.

Conversely, when the load device 450 enters the standby mode, neither the control unit 431 nor the current detecting circuit 432 generates the mode setting result MR of the logic high level and the detection result signal DR. Therefore, OR gate OR1 will provide a logic low level select signal SEL to turn off select switch SW1. The driving current supplied from the voltage conversion device 400 is effectively reduced.

Incidentally, the setting of the mode setting result MR, the detection result signal DR, and the logic level of the selection signal SEL in the above embodiment is merely an example and is not intended to limit the scope of the present invention.

Please refer to FIG. 4B. FIG. 4B illustrates an embodiment of the embodiment of the present invention illustrated in FIG. 4A. The one end of the selection switch SW1 in the current path selector 460 of the present embodiment receives the DC input voltage DCVIN, and the other end thereof selects the first end of the current transmission path 461 or the current transmission path 462 according to the selection signal SEL. One end. The second ends of the current transmission paths 461 and 462 are coupled to the output of the current path selector 460, and the equivalent impedance provided by the current transmission path 461 is greater than the equivalent impedance provided by the current transmission path 462. In brief, the current path selector 460 uses the selection switch SW1 to select one of the current transmission paths 461 or 462 to transmit the DC input voltage DCVIN. The drive current supplied by the voltage conversion device 400 is adjusted by the difference in equivalent impedances provided by the current transmission paths 461 and 462.

Please refer to FIG. 5. FIG. 5 illustrates another embodiment of the embodiment of FIG. 4A of the present invention. The voltage conversion device 500 is a resistive voltage conversion device. The current path selector 520 utilizes a resistor RA to form a current transmission path that provides a higher impedance, and utilizes the switch SW1 to form a current transmission path that provides a lower impedance.

In addition, the current detecting circuit 532 in the load state detector 530 includes a comparator CMP1, a sensing resistor R2, and a threshold voltage source VO. The sense resistor R2 is connected in series between the first input of the comparator CMP1 and the output of the current path selector 520. The threshold voltage source VO is connected in series between the second input of the comparator CMP1 and the output of the current path selector 520 to provide a threshold voltage. The comparator CMP1 compares the signals received by the two inputs, and generates a detection result signal DR at its output. Incidentally, capacitors C3 and C4 are voltage stabilizing capacitors.

Please refer to FIG. 6 below. FIG. 6 illustrates still another embodiment of the embodiment of FIG. 4A of the present invention. The voltage conversion device 600 includes a current path selector 620 and a load status detector 630. Unlike the embodiment illustrated in FIG. 5, the voltage conversion device 600 is a capacitive voltage conversion device. That is to say, the present invention utilizes different current transmission paths to provide different driving currents, and can be implemented not only in the resistive voltage converting device but also in the capacitive voltage converting device.

In summary, the present invention selects a current transmission path of a DC input voltage by the load device driven by the voltage conversion device being in an active mode or a standby mode. The equivalent impedance is adjusted by selecting different current transmission paths to control the magnitude of the driving current output by the voltage conversion device. The current demand state of the load device is effectively adjusted to dynamically adjust the drive current output by the voltage conversion device to reduce the consumption of the drive current and increase the energy use efficiency.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

110, 120, 200, 300, 400, 500, 600. . . Voltage converter

111, 121. . . load

210, 310, 410. . . Rectifier

220, 320, 420, 460, 520, 620. . . Current path selector

230, 330, 430, 530, 630. . . Load status detector

240, 340, 440. . . Regulator circuit

250, 350, 450. . . Load device

221, 222, 321, 322, 421, 422, 461, 462. . . Current transmission path

231, 331, 431. . . control unit

332, 432, 532, 632. . . Current detection circuit

CMP1. . . Comparators

OR1. . . Gate

VO. . . Threshold voltage source

DR. . . Detection result signal

MR. . . Mode setting result

ACVIN. . . AC input voltage

DCVIN. . . DC input voltage

P1, P2. . . End point

DCVOUT. . . DC output voltage

SEL. . . Selection signal

SW1. . . switch

MODSET. . . Mode setting signal

C2, C3, C4. . . Voltage stabilizing capacitor

D1. . . Dipole

ZD1. . . Zener diode

R1, R2, RA. . . resistance

C1. . . capacitance

LS. . . Load setting signal

1A and 1B are circuit diagrams of conventional resistive and capacitive AC DC voltage converters 110, 120, respectively.

2 is a schematic diagram of a voltage conversion device 200 in accordance with an embodiment of the present invention.

FIG. 3 is a schematic diagram of a voltage conversion device 300 according to another embodiment of the present invention.

4A is a schematic diagram of a voltage conversion device 400 in accordance with still another embodiment of the present invention.

FIG. 4B illustrates an embodiment of the embodiment of FIG. 4A of the present invention.

FIG. 5 illustrates another embodiment of the embodiment of FIG. 4A of the present invention.

FIG. 6 illustrates still another embodiment of the embodiment of FIG. 4A of the present invention.

200. . . Voltage converter

210. . . Rectifier

220. . . Current path selector

230. . . Load status detector

240. . . Regulator circuit

250. . . Load device

221, 222. . . Current transmission path

ACVIN. . . AC input voltage

DCVIN. . . DC input voltage

P1, P2. . . End point

DCVOUT. . . DC output voltage

SEL. . . Selection signal

SW1. . . switch

MODSET,. . . Mode setting signal

ZD1. . . Zener diode

C2. . . Voltage stabilizing capacitor

LS. . . Load setting signal

Claims (16)

A voltage conversion device for receiving an AC input voltage and generating a DC output voltage to convert a load device according to converting the AC input voltage, comprising: a rectifier receiving the AC input voltage and generating a DC input voltage accordingly a current path selector having an input end and an output end, the input end receiving the DC input voltage, and the output end generating the DC output voltage, comprising: a first current transmission path and a second current transmission path, serially connected Between the input end and the output end of the current path selector, the current path selector selects to transmit the DC input by at least one of the first current transmission path and the second current transmission path according to a selection signal a voltage to an output of the current path selector, thereby changing an equivalent impedance between an input end and an output end of the current path selector; and a load state detector coupled to the output of the current path selector and the The load device generates the selection signal according to detecting a current demand state of the load device. The voltage conversion device of claim 1, wherein the load state detector comprises: a control unit coupled to the output of the current path selector and the load device, receiving and according to a mode setting signal This selection signal is generated. The voltage conversion device of claim 2, wherein the control unit generates a load setting signal according to the mode setting signal, and receives and controls the current demand state of the load device according to a mode setting signal. The voltage conversion device of claim 1, wherein the load state detector comprises: a current detecting circuit coupled to the output of the current path selector for detecting the current path selector An output current, and a detection result signal is generated according to the output current; a control unit coupled to the current detection circuit and the load device, receiving a mode setting signal to generate a mode setting result; and a logic operation circuit, The current detecting circuit, the control unit and the current path selector are coupled to receive and perform a logic operation according to the detection result signal and the mode setting result to generate the selection signal. The voltage conversion device of claim 4, wherein the current detecting circuit comprises: a comparator, wherein the output end generates the detection result signal; and a sensing resistor is serially connected to the first of the comparator An input terminal and an output of the current path selector; and a threshold voltage source connected in series between the second input of the comparator and the output of the current path selector for providing a threshold voltage. The voltage conversion device of claim 4, wherein the control unit further generates a load setting signal according to the mode setting signal, and receives and controls the current demand state of the load device according to a mode setting signal. The voltage conversion device of claim 4, wherein the logic operation unit is an OR gate, and the input end of the OR gate receives the detection result signal and the mode setting result, and generates the selection at the output end thereof. signal. The voltage conversion device of claim 1, wherein the load state detector comprises: a current detecting circuit coupled to the output of the current path selector for detecting the current path selector An output current is generated, and the selection signal is generated according to the output current. The voltage conversion device of claim 8, wherein the current detecting circuit comprises: a comparator, the output terminal generates the selection signal; and a sensing resistor serially connected to the first input end of the comparator And an output of the current path selector; and a threshold voltage source connected in series between the second input of the comparator and the output of the current path selector to provide a threshold voltage. The voltage conversion device of claim 8, wherein the load state detector further comprises: a control unit coupled to the current detecting circuit and the load device, receiving and controlling the signal according to a mode setting signal The current demand state of the load device. The voltage conversion device of claim 1, further comprising: a voltage stabilizing circuit coupled to the output of the current path selector for stabilizing the voltage value of the DC output voltage. The voltage conversion device of claim 11, wherein the voltage stabilizing circuit comprises: a Zener diode connected in series between the output of the current path selector and a ground voltage; and a The voltage stabilizing capacitor is coupled in parallel with the Zener diode. The voltage conversion device of claim 1, wherein the current path selector further comprises: a selection switch, the one end receiving the DC input voltage and the first end of the first current transmission path, and the other end coupled Connected to the first end of the second current transmission path, the selection switch receives the selection signal to be turned on or off, wherein the second ends of the first and second current transmission paths are coupled to the output of the current path selector end. The voltage conversion device of claim 13, wherein the first current transmission path provides an equivalent impedance greater than an equivalent impedance provided by the second current transmission path. The voltage conversion device of claim 1, wherein the current path selector further comprises: a selection switch, one end of which receives the DC input voltage, and the other end of which is coupled to the first current transmission according to the selection signal a first end of the path or a first end of the second current transmission path, wherein the second ends of the first and second current transmission paths are coupled to an output of the current path selector, and the first current is transmitted The equivalent impedance provided by the path is greater than the equivalent impedance provided by the second current transfer path. The voltage conversion device of claim 1, wherein the current demand state is a current consumed by the load device when the load device is turned on or off.