CN112653341A - Power detection power controller - Google Patents
Power detection power controller Download PDFInfo
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- CN112653341A CN112653341A CN201910952882.4A CN201910952882A CN112653341A CN 112653341 A CN112653341 A CN 112653341A CN 201910952882 A CN201910952882 A CN 201910952882A CN 112653341 A CN112653341 A CN 112653341A
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- 238000001514 detection method Methods 0.000 title claims abstract description 49
- 238000012545 processing Methods 0.000 claims abstract description 12
- 238000000034 method Methods 0.000 claims description 22
- 230000008569 process Effects 0.000 claims description 21
- 239000003990 capacitor Substances 0.000 claims description 16
- 230000000087 stabilizing effect Effects 0.000 claims description 11
- 230000003247 decreasing effect Effects 0.000 claims description 9
- 230000008878 coupling Effects 0.000 claims description 4
- 238000010168 coupling process Methods 0.000 claims description 4
- 238000005859 coupling reaction Methods 0.000 claims description 4
- 230000006641 stabilisation Effects 0.000 claims description 4
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- 238000006243 chemical reaction Methods 0.000 claims description 3
- 230000005674 electromagnetic induction Effects 0.000 claims description 3
- 239000004065 semiconductor Substances 0.000 claims description 2
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- 230000001186 cumulative effect Effects 0.000 description 10
- 238000010586 diagram Methods 0.000 description 8
- 230000005856 abnormality Effects 0.000 description 6
- 230000008859 change Effects 0.000 description 3
- 230000000630 rising effect Effects 0.000 description 3
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
- H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
- H02M7/12—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/21—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M7/217—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M7/2173—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only in a biphase or polyphase circuit arrangement
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
- H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
- H02H7/125—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for rectifiers
- H02H7/1252—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for rectifiers responsive to overvoltage in input or output, e.g. by load dump
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
- H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
- H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/3353—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having at least two simultaneously operating switches on the input side, e.g. "double forward" or "double (switched) flyback" converter
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
Abstract
The invention relates to a power detection power controller, which is provided with a working voltage pin, a grounding pin, a pulse width modulation driving pin, a current sensing pin and a load feedback pin and is used for converting an input alternating voltage input from the outside into an output voltage and supplying the output voltage to a load. Particularly, the power detection power controller also simultaneously carries out load power detection processing, adds one to, subtracts one from or keeps unchanged the power count value by comparing the load feedback signal with the load critical voltage value representing the load critical power, and judges whether overload abnormity occurs or not by comparing the power count value with the power judgment count value so as to provide overload protection.
Description
Technical Field
The invention relates to a power detection power controller, in particular to a power detection power controller which compares a load feedback signal with a load critical voltage value representing load critical power, adds one to, subtracts one from or maintains the power count value unchanged, judges whether overload abnormity occurs by comparing the power count value with a power judgment count value to provide overload protection, and converts an input alternating current voltage input from the outside into an output voltage to supply to a load.
Background
Different electrical products require a specific power supply, such as a dc power supply or an ac power supply, and furthermore, the voltage and current requirements vary considerably. For example, a typical integrated circuit requires a relatively low voltage DC power supply, such as 1.8V, while an electric motor may require a relatively high driving voltage and current, and a lamp of a liquid crystal display requires a relatively high operating voltage AC power supply.
Therefore, an appropriate power converter must be configured to convert the original input power to the required power to ensure proper operation.
In the prior art, a Switching power converter (Switching) with high power conversion efficiency and convenient control has been developed and widely applied to many electronic products. The switching power converter mainly uses a controller to generate a driving control signal with a higher switching frequency to drive a power transistor as a switch, and converts an input power into an output power with a required voltage through a transformer by rapidly switching the power transistor on or off.
It is known that electronic products are sensitive to heat accumulation and temperature rise during operation, because excessive temperature can cause malfunction, failure and even permanent damage of electronic components, and therefore, a mechanism for preventing the occurrence of excessive load is required. The most common method is to use a temperature sensing element, such as a thermistor, and when the temperature is too high, the resistance of the thermistor will change greatly, so that the controller can detect the change of the resistance to determine whether the overload occurs, and then take necessary processing, such as stopping power supply to the load. However, the thermistor is expensive and occupies a considerable area on the circuit board, which affects the overall circuit layout.
Another approach is to use the temperature detection technique of electronic circuit, but the circuit design is complex, requires a very stable bandgap circuit (Bang gap) to be configured, and usually requires a wafer fabrication (Fundry) to provide proper process coordination, and furthermore, the practical achieved performance is very limited.
Therefore, there is a need in the electronic/electrical industry for a power detection power controller with a novel design, which compares a load feedback signal with a load threshold voltage value representing the load threshold power, and adds, subtracts or maintains the power count value unchanged, and compares the power count value with a power judgment count value to determine whether an overload abnormality occurs to provide overload protection, and converts an externally input ac voltage into an output voltage to supply the load, so as to overcome the problems in the prior art.
Disclosure of Invention
The main objective of the present invention is to provide a power detection power controller, which has a working voltage pin, a ground pin, a Pulse Width Modulation (PWM) driving pin, a current sensing pin, and a load feedback pin, and is used to convert an externally input ac voltage into an output voltage, and supply a load with the output voltage.
Specifically, the power detection power controller operates in cooperation with a rectifying unit, a transformer, a switching unit, a current sensing resistor, an output rectifying unit, and an output capacitor.
Further, the transformer includes a primary side inductor and a secondary side inductor, and the rectifying unit, the primary side inductor, the switching unit and the current sensing resistor are sequentially connected in series between the input ac voltage and the ground potential, and the secondary side inductor, the output rectifying unit and the output capacitor are sequentially connected in series. In addition, the load is connected in parallel to the output capacitor.
Furthermore, the primary side current flowing through the primary side inductor also flows through the switching unit, and is used as the conducting current when the switching unit is turned on and conducted. The primary side current generates a secondary side current in the secondary side inductor through the action of electromagnetic induction, and the secondary side current flows through the output rectifying unit and the load, so that an output voltage is generated at the connection point of the secondary side inductor and the output capacitor. In addition, the connection point of the switching unit and the current sensing resistor can generate a current sensing signal.
More specifically, the operating voltage pin receives an operating voltage to operate, and the voltage stabilizing unit and the rectifying circuit are connected to the operating voltage pin, wherein the voltage stabilizing unit receives an input ac voltage to stabilize the voltage, the rectifying circuit is connected to an auxiliary inductor coupled to the secondary side inductor to receive an auxiliary voltage generated by the auxiliary inductor by sensing a current at the secondary side, and the operating voltage is generated by the voltage stabilizing unit and the rectifying circuit.
The ground pin is connected to ground potential, the PWM driving pin is connected to the switching unit and used for transmitting a PWM driving signal to drive the switching unit to be turned on or turned off and not to be turned on, the PWM driving signal has a period, meanwhile, the current sensing pin receives a current sensing signal, and the load feedback pin receives a load feedback signal generated by a load feedback circuit connected to a load. In addition, the load feedback signal is a voltage (i.e., output voltage), current, or power corresponding to the load.
In addition, the load power detection process of the power detection power controller of the present invention includes the following steps.
In step S10, the load feedback signal and the load threshold voltage value representing the load threshold power are compared at predetermined power counting intervals. In step S20, if the load feedback signal is greater than the load threshold voltage value, the power count value is increased by one; in step S30, if the load feedback signal is equal to the load threshold voltage value, the power count value is unchanged; in step S40, if the load feedback signal is less than the load threshold voltage value, the power count value is decreased by one.
In step S50, comparing the power count value with a preset power determination count value every preset power determination time; in step S60, if the power count value is greater than the power determination count value, the overload protection process is started, and the output of the PWM driving signal is stopped to turn off the switching unit; in step S70, if the power count value is not greater than the power determination count value, the overload protection process is not started, and returns to step S10, and all steps are repeated.
Therefore, the invention utilizes the comparison of the load feedback signal and the load critical voltage value representing the load critical power to add, subtract or maintain the power counting value unchanged, and judges whether the overload abnormity occurs by comparing the power counting value and the power judging counting value to provide overload protection, and simultaneously converts the input alternating voltage input from the outside into the output voltage to supply the load.
Drawings
Fig. 1 is a schematic diagram illustrating an operation flow of a power detection power controller according to an embodiment of the present invention.
FIG. 2 is a schematic diagram of an exemplary application of a power detection power controller according to an embodiment of the invention.
Fig. 3 is a waveform diagram illustrating an operation of a load power detection process in a power controller according to an embodiment of the present invention.
FIG. 4 is a waveform diagram illustrating another operation of a load power detection process in a power controller according to an embodiment of the present invention.
Fig. 5 is a waveform diagram illustrating another operation of a load power detection process in a power controller according to an embodiment of the present invention.
Wherein the reference numerals are as follows:
10 power detection power controller
20 rectifying unit
30 transformer
40 switching unit
50 current sensing resistor
60 output rectifying unit
70 output capacitance
80 voltage stabilizing unit
90 rectification circuit
FB load feedback circuit
GND ground potential
IP primary side current
IS secondary side current
IDS conduction current
LA auxiliary inductor
LP primary side inductance
LS secondary side inductor
P1, P2, P3, P4 time intervals
Q1, Q21, Q22, Q23, Q24, Q3, Q4 time intervals
R1, R2, R3 time intervals
RL load
S10, S20, S30 and S40 steps
S50, S60, S70 steps
T1 working voltage pin
T2 grounding pin
T3 PWM driving pin
T4 current sensing pin
T5 load feedback pin
VAC input AC voltage
VCS current sense signal
VGS PWM drive signal
VOUT output voltage
VTH load critical voltage value
Detailed Description
The embodiments of the present invention will be described in more detail with reference to the drawings and the accompanying reference numerals, so that those skilled in the art can implement the embodiments of the present invention after studying the specification.
Referring to fig. 1 and fig. 2, fig. 1 is a schematic diagram illustrating an operation flow of a power detection power controller according to an embodiment of the present invention, and fig. 2 is a schematic diagram illustrating an application example of the power detection power controller according to the embodiment of the present invention. As shown in fig. 1 and fig. 2, the power detection power controller 10 according to the embodiment of the invention includes a working voltage pin T1, a ground pin T2, a Pulse Width Modulation (PWM) driving pin T3, a current sensing pin T4 and a load feedback pin T5, and is configured to convert an input ac voltage VAC from an external input into an output voltage VOUT and supply the output voltage VOUT to a load RL, and at the same time, performs a load power detection process including steps S10, S20, S30, S40, S50, S60 and S70 to provide an Overload Protection (OLP), and the power detection power controller 10 is configured with a rectifying unit 20, a transformer 30, a switching unit 40, a current sensing resistor 50, an output rectifying unit 60 and an output capacitor 70.
For example, the switching element 40 may comprise a Metal-Oxide-Semiconductor (MOS) element or a bipolar (bipolar) element, but for convenience of illustration, the MOS element is an exemplary example.
Specifically, the transformer 30 includes a primary inductor LP and a secondary inductor LS, and the rectifying unit 20, the primary inductor LP, the switching unit 40, and the current sensing resistor 50 are sequentially connected in series between the input ac voltage VAC and the ground potential GND, and the secondary inductor LS, the output rectifying unit 60, and the output capacitor 70 are sequentially connected in series, and the load RL is connected in parallel to the output capacitor 70.
Further, the primary side current IP flowing through the primary side inductor LP also flows through the switching unit 40, and is a conduction current IDS when the switching unit 40 is turned on to conduct. In addition, the primary side current IP generates a secondary side current IS in the secondary side inductor LS through electromagnetic induction, wherein the secondary side current IS flows through the output rectifying unit 60 and the load RL, and the output voltage VOUT IS generated at the connection point of the secondary side inductor LS and the output capacitor 70. The connection point of the switching unit 40 and the current sensing resistor 50 generates a current sensing signal VCS.
More specifically, the operating voltage pin T1 of the power detection power controller 10 IS used for receiving the operating voltage VCC to operate, and the voltage stabilization unit 80 and the rectification circuit 90 are respectively connected to the operating voltage pin T1, wherein the voltage stabilization unit 80 receives the input ac voltage VAC to perform voltage stabilization, and the rectification circuit 90 IS connected to the auxiliary inductor LA coupled to the secondary inductor LS for receiving and rectifying the auxiliary voltage generated by the auxiliary inductor LA by sensing the secondary side current IS. Further, the voltage stabilizing unit 80 and the rectifying circuit 90 generate the operating voltage VCC.
For example, the voltage stabilizing unit 80 may include a first voltage dividing resistor, a second voltage dividing resistor, and an input capacitor (not shown), wherein the first voltage dividing resistor is connected to the second voltage dividing resistor, the input capacitor is connected between a connection point of the first voltage dividing resistor and the second voltage dividing resistor and the ground potential GND, and the connection point of the first voltage dividing resistor and the second voltage dividing resistor is further connected to the operating voltage pin T1. In addition, the rectifying circuit 90 may include a resistor and a diode (not shown) connected in series, wherein the resistor is connected to the auxiliary inductor LA, and the diode is connected to the operating voltage pin T1.
The ground pin T2 is connected to the ground potential GND.
The PWM driving pin T3 is connected to the switching unit 40 for transmitting a PWM driving signal VGS having a specific period and driving the switching unit 40 to be turned on or turned off.
The current sense pin T4 receives the current sense signal VCS, the load feedback pin T5 receives the load feedback signal VCOM generated by the load feedback circuit FB connected to the load RL, and the load feedback signal VCOM corresponds to the current, voltage or power of the load RL. For example, if the load feedback signal VCOM is a voltage representing the load RL, i.e. the output voltage VOUT, the load feedback circuit FB may be composed of a light emitting diode and a photo coupling element that are isolated from each other without physical contact, wherein the light emitting diode receives the output voltage VOUT and emits a light signal to the photo coupling element, and the photo coupling element converts the light signal into the desired load feedback signal VCOM, thereby achieving the purpose of converting the output voltage VOUT into the load feedback signal VCOM in an isolated manner, but the scope of the invention is not limited thereto. However, for convenience of explanation, the load feedback signal VCOM is used as an example of the voltage corresponding to the load RL (i.e., the output voltage VOUT) in the following.
In summary, the power detection controller 10 of the present invention generates the PWM driving signal VGS according to the current sensing signal VCS and the load feedback signal VCOM, and performs the load power detection process by using the load feedback signal VCOM to generate the power counting value representing the average load power.
Since the manner of generating the PWM driving signal VGS according to the current sensing signal VCS and the load feedback signal VCOM is commonly used in the prior art, it is not described in detail below.
The processing steps performed by the load power detection process will be described step by step, and for clearly explaining the features of the present invention, two exemplary operation waveforms of the load power detection process are shown in fig. 3 and 4, respectively.
First, in step S10, the load feedback signal VCOM and the load threshold voltage value VTH representing the load threshold power are compared at predetermined power counting time intervals as shown in fig. 3 and 4, wherein the waveform of the load feedback signal VCOM is the same up-down curve including continuous linear ascending segments and linear descending segments, although the invention can cover other curves, such as wave-shaped, as an example, only.
Next, in step S20, if the load feedback signal VCOM is greater than the load threshold voltage VTH, the power count value is incremented by one. In step S30, if the load feedback signal VCOM is equal to the load threshold voltage VTH, the power count value remains unchanged. In step S40, if the load feedback signal VCOM is smaller than the load threshold voltage VTH, the power count value is decreased by one.
In other words, the load threshold voltage VTH is a parameter for determining whether the system is overloaded, and the power count value is a parameter representing the average load power. Comparing the load threshold VTH of fig. 3 and fig. 4, wherein the load threshold VTH of fig. 3 is larger than the load threshold VTH of fig. 4, and the overload requirement of the system using the lower load threshold VTH is more strict because the load threshold VTH is a parameter for determining whether the overload occurs.
The waveforms of fig. 3 are detailed, wherein the time intervals P1, P2, P3, and P4 represent the time duration between two adjacent cross points of the load feedback signal VCOM and the load threshold VTH, respectively. Further, the time intervals P1 and P3 are the time intervals when the load feedback signal VCOM is greater than the load threshold voltage VTH, so that the power count value representing the average load power is continuously increased by one every power count time in the time intervals P1 and P3. In addition, the time intervals P2 and P4 are the time intervals when the load feedback signal VCOM is smaller than the load threshold voltage VTH, so the power count value is continuously decreased by one every power count time in the time intervals P2 and P4.
In contrast, the cumulative time of time intervals P1, P3 is significantly shorter than the cumulative time of time intervals P2, P4, so the rising cumulative count of power counts is less than the falling cumulative count, indicating that the average load power is in a falling trend.
Referring to the waveforms of fig. 4, the time intervals Q1, Q21, Q22, Q23, Q24, Q3, and Q4 respectively represent the time duration between two adjacent cross points of the load feedback signal VCOM and the load threshold VTH. During the time intervals Q1, Q22, and Q3, the load feedback signal VCOM is greater than the load threshold voltage VTH, so the power count value is increased by one every power counting time, and during the time intervals Q21, Q23, and Q4, the power count value is decreased by one every power counting time. It is apparent that the cumulative time of time intervals Q1, Q22, Q3 is significantly longer than the cumulative time of time intervals Q21, Q23, Q4, so the rising cumulative value of the power count values is greater than the falling cumulative value, indicating that the average load power is in a rising trend.
In other words, for the same waveform of the load feedback signal VCOM, if the lower load threshold VTH is selected, the power count value is easier to rise, i.e. the overload criterion is stricter.
After step S40, the process proceeds to step S50, where the power count value and the preset power determination count value are compared at preset power determination time intervals.
In step S60, if the power count value IS greater than the power determination count value, which indicates that an overload abnormality occurs, the overload protection process IS immediately started to stop outputting the PWM driving signal VGS, and further turn off the switching unit 40, that IS, the primary side current IP IS zero and the secondary side current IS also zero, and the system stops providing the output voltage VOUT to the load RL, thereby specifically implementing overload protection and avoiding damage to related components.
In step S70, if the power count value is not greater than the power determination count value, indicating that the overall system is operating normally and no overload abnormality has occurred, the overload protection process is not started, and the process returns to step S10, and all the steps described above are repeated.
Therefore, when viewed on a time scale larger than the power counting time, i.e., the power determination time, the decrease or increase of the power counting value may represent that the average load power is decreasing or increasing. For example, the power counting time may be 10 to 1000 times of the period of the PWM driving signal, and the power determining time may be 20 to 2000 times of the power counting time.
As another example, fig. 5 shows a waveform diagram of another operation of the load power detection process of the present invention, wherein the waveform of the load feedback signal VCO M is different from that of fig. 4, but the load threshold voltage value VTH is the same.
In fig. 5, the time intervals R1 and R3 indicate that the load feedback signal VCOM is smaller than the load threshold VTH, so that the power count value is decreased by one, i.e., decreased, every power counting time, and the time interval R2 indicates that the load feedback signal VCOM is greater than the load threshold VTH, so that the power count value is increased by one, i.e., increased, every power counting time. Since the cumulative time of such time intervals R1, R3 is significantly greater than the cumulative time of such time intervals R2, the average load power is in a continuous decline. In other words, the operation of fig. 5 does not cause an overload to occur.
More specifically, the power detection power controller 10 of the present invention includes a first Analog-to-digital conversion (ADC) unit, a second ADC unit and a digital processing core unit (not shown), wherein the first ADC unit is used for receiving a current sensing signal VCS to generate a digital current sensing signal, the second ADC unit is used for receiving a load feedback signal VCOM to generate a digital load feedback signal, and the digital processing core unit receives the digital current sensing signal and the digital load feedback signal to generate a PWM driving signal VGS, and performs the load power detection process.
Particularly, the Digital processing core unit may be implemented by a Microprocessor (MCU) executing a firmware program, and particularly, the microprocessor does not have any analog circuit but is composed of a plurality of Digital Logic Gate (Digital Logic Gate) gates. Preferably, the power detection power controller 10 including the first ADC unit, the second ADC unit and the digital processing core unit is a highly integrated single chip. Therefore, the best overload protection can be achieved by updating the firmware program to change the power counting time and the power determination time according to the actual requirement.
In summary, the present invention is characterized in that a power count value is increased, decreased or maintained by comparing a load feedback signal with a load threshold voltage value representing a load threshold power, and whether an overload abnormality occurs is determined by comparing the power count value with a power determination count value to provide overload protection, and an input ac voltage inputted from an external is converted into an output voltage to supply to a load.
The present invention has another characteristic that the judgment of the overload can be achieved only by a single power counting value, so the whole framework is very simple and easy to implement, and especially, the power detection power controller with a microprocessor is used for providing a digital processing function, so that the average load power can be rapidly and accurately monitored, whether the overload abnormality occurs is judged, and the overload protection processing is immediately started when the overload abnormality occurs, the output of the PWM driving signal is stopped, the switching unit is closed, the damage of related elements is avoided, and the operation safety is improved.
The foregoing is illustrative of the preferred embodiment of the present invention and is not to be construed as limiting thereof, since any modification or variation thereof within the spirit of the invention is intended to be covered thereby.
Claims (9)
1. A power detection power controller is characterized in that a rectifying unit, a transformer, a switching unit, a current sensing resistor, an output rectifying unit and an output capacitor are matched for converting an input alternating voltage input from outside into an output voltage and supplying a load by the output voltage, the transformer comprises a primary side inductor and a secondary side inductor, the rectifying unit, the primary side inductor, the switching unit and the current sensing resistor are sequentially connected in series between the input alternating voltage and a grounding potential, the secondary side inductor, the output rectifying unit and the output capacitor are sequentially connected in series, the load is connected in parallel to the output capacitor, a primary side current flowing through the primary side inductor also flows through the switching unit and serves as a conducting current when the switching unit is switched on, the primary side current generates a secondary side current at the secondary side inductor through an electromagnetic induction effect, the secondary side current flows through the output rectifying unit and the load, and the output voltage is generated at a connection point of the secondary side inductor and the output capacitor, the switching unit and a connection point of the current sensing resistor generate a current sensing signal, and the power detection power controller is provided with:
a working voltage pin for receiving a working voltage to work;
a ground pin connected to the ground potential;
a Pulse Width Modulation (PWM) driving pin connected to the switching unit for transmitting a PWM driving signal to drive the switching unit to be turned on or turned off, the PWM driving signal having a period;
a current sensing pin for receiving the current sensing signal; and
a load feedback pin for receiving a load feedback signal generated by a load feedback circuit connected to the load, the load feedback signal corresponding to the output voltage, a current of the load or a power of the load,
wherein the power detection power controller generates the PWM driving signal according to the current sensing signal and the load feedback signal, and performs a load power detection process using the load feedback signal to generate a power count value representing an average load power, the load power detection process including the following steps:
comparing the load feedback signal with a load critical voltage value representing a load critical power every preset power counting time;
if the load feedback signal is greater than the load critical voltage value, the power count value is increased by one;
if the load feedback signal is equal to the load threshold voltage value, the power count value is unchanged;
if the load feedback signal is less than the load threshold voltage value, the power count value is decreased by one;
comparing the power count value with a preset power judgment count value every preset power judgment time;
if the power count value is larger than the power judgment count value, starting an overload protection process, stopping outputting the PWM driving signal and closing the switching unit; and
if the power count value is not greater than the power judgment count value, the overload protection process is not started, and all the steps are repeated.
2. The power detection power controller of claim 1, wherein the power detection power controller comprises:
a first Analog-to-digital conversion (ADC) unit for receiving the current sensing signal and generating a digital current sensing signal;
a second ADC unit for receiving the load feedback signal and generating a digital load feedback signal; and
a digital processing core unit for receiving the digital current sensing signal and the digital load feedback signal to generate the PWM driving signal and performing the load power detection processing.
3. The power detection power controller of claim 2, wherein the Digital processing core is implemented by a Microprocessor (MCU) executing a firmware program, and the microprocessor has no analog circuit but comprises a plurality of Digital Logic Gate (Digital Logic Gate) gates.
4. The power detection power controller of claim 1, wherein the power counting time is between 10 and 1000 times the period of the PWM driving signal, and the power determination time is between 20 and 2000 times the power counting time.
5. The power detection power controller of claim 1, wherein the switching element comprises a Metal-Oxide-Semiconductor (MOS) element or a bipolar element.
6. The power detection power controller of claim 1, wherein the voltage stabilizing unit comprises a first voltage dividing resistor, a second voltage dividing resistor and an input capacitor, the first voltage dividing resistor is connected to the second voltage dividing resistor, the input capacitor is connected between a connection point of the first voltage dividing resistor and the second voltage dividing resistor and the ground potential, and the connection point of the first voltage dividing resistor and the second voltage dividing resistor is further connected to the working voltage pin.
7. The power detection power controller of claim 1, wherein the rectifying circuit comprises a resistor and a diode connected in series, the resistor is connected to the auxiliary inductor, and the diode is connected to the working voltage pin.
8. The power detection power controller of claim 1, wherein the load feedback circuit is formed by a light emitting diode and an optical coupling element.
9. The power detection power controller of claim 1, further comprising a voltage stabilizing unit and a rectifying circuit, wherein the voltage stabilizing unit and the rectifying circuit are connected to the working voltage pin, the voltage stabilizing unit receives the input ac voltage for voltage stabilization, and the rectifying circuit is connected to an auxiliary inductor coupled to the secondary inductor for receiving an auxiliary voltage generated by the auxiliary inductor by sensing the secondary side current, the working voltage being generated by the voltage stabilizing unit and the rectifying circuit.
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| CN201910952882.4A CN112653341A (en) | 2019-10-09 | 2019-10-09 | Power detection power controller |
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| CN201910952882.4A CN112653341A (en) | 2019-10-09 | 2019-10-09 | Power detection power controller |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN1949615A (en) * | 2005-10-14 | 2007-04-18 | 崇贸科技股份有限公司 | Over-power protector capable of regulating over-current level |
| CN104333955A (en) * | 2014-11-11 | 2015-02-04 | 电子科技大学 | Numerically controlled LED drive circuit |
| CN107465171A (en) * | 2016-06-02 | 2017-12-12 | 快捷韩国半导体有限公司 | Overload protection for power converter |
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2019
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1949615A (en) * | 2005-10-14 | 2007-04-18 | 崇贸科技股份有限公司 | Over-power protector capable of regulating over-current level |
| CN104333955A (en) * | 2014-11-11 | 2015-02-04 | 电子科技大学 | Numerically controlled LED drive circuit |
| CN107465171A (en) * | 2016-06-02 | 2017-12-12 | 快捷韩国半导体有限公司 | Overload protection for power converter |
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