CN105873307A - Device and method for adjusting power supply output current - Google Patents
Device and method for adjusting power supply output current Download PDFInfo
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- CN105873307A CN105873307A CN201510027212.3A CN201510027212A CN105873307A CN 105873307 A CN105873307 A CN 105873307A CN 201510027212 A CN201510027212 A CN 201510027212A CN 105873307 A CN105873307 A CN 105873307A
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Abstract
A device for adjusting a power supply output current comprises a power supply circuit, an adjustment circuit and a current control loop. The power supply circuit comprises an input terminal and an output terminal, receives input power and supplies output power. The regulation circuit samples an output current at the output terminal to obtain an output current sample value, adjusts the output current sample value according to an external adjustment signal, and outputs a current feedback signal. The current control loop provides a switch control signal for the power supply circuit according to the output current feedback signal. According to the technical scheme, the device can adjust the power supply output current according to the current adjustment signal and can be used as a light-adjustable LED drive power supply.
Description
Technical field
The invention relates to power circuit, and in particular to the method for regulation power circuit output electric current.
Background technology
The i.e. PWM of digital dimming dims, and PWM light adjusting circuit is to utilize pwm signal to control LED lower power to switch on-off, and realizes the control to LED brightness changing average output current.PWM light modulation is that the method for pulsewidth modulation with the switch operating frequency more than 100Hz changes the pulse duty factor of LED drive current to realize the brightness adjustment control of LED, selects and controls frequency more than 100Hz switch dimming primarily to avoid human eye to feel light modulation scintillation.Under the control of pwm signal, the luminosity of LED is proportional to the pulse duty factor of PWM.The loss of this light-dimming method is big, and easily makes LED lamp scintillation occur.
Summary of the invention
The present invention provides a kind of device and method regulating electric power outputting current, it is possible to quickly follow the output electric current of regulation signal conversion power unit.Can be applicable to LED drive power, it is achieved according to the dutycycle of PWM dim signal, quickly regulate the output electric current of power supply, it is achieved LED dims.
Technical scheme, a kind of device regulating electric power outputting current, including, power circuit, regulation circuit and current regulator, described power circuit has input and output, and it receives input electric energy from input and provides output electric energy at output；The electric current of the output of power circuit described in described regulation circuit sampling, and according to regulation Signal Regulation sampled reference, obtain exporting current feedback signal, output is to current regulator；Described current regulator provides control signal according to output current feedback signal for described power circuit so that regulating signal intensity described in the output current following of power circuit.
In one specific embodiment of the present invention, described regulation signal is that the PWM of a change in duty cycle regulates signal.
In one specific embodiment of the present invention, described regulation circuit is one can be described sampled reference according to the resistance sampling circuit of described regulation Signal Regulation resistance value, described resistance value.
In one specific embodiment of the present invention, described regulation circuit includes the first resistance, the second resistance and switch, with described second resistor coupled in parallel after described first resistance and the series connection of described switch.
In one specific embodiment of the present invention, described regulation circuit includes the first resistance, the second resistance and switch, with the second resistant series after described first resistance and described switch in parallel.
In one specific embodiment of the present invention, the switch of described regulation circuit accepts the control of described PWM regulation signal, and it is according to PWM regulation signal conduction and shutoff.
In one specific embodiment of the present invention, described power circuit is an isolated variable circuit, and described regulation circuit connected in series is on the former limit of isolated variable circuit.
In one specific embodiment of the present invention, described isolated variable circuit is an anti exciting converter, and described regulation circuit is connected with the primary side winding of the isolating transformer of described anti exciting converter.
The present invention also provides for a kind of method regulating electric power outputting current, comprises the steps:
Step one: use regulation circuit to receive regulation signal；
Step 2: change the resistance of sampling resistor in regulation circuit according to regulation signal.
The present invention one specific embodiment also includes step 3: use electric power outputting current described in described regulation circuit sampling, and output current feedback signal；
Step 4: use current regulator to control the output electric current of described power supply according to output current feedback signal.
For the features described above of the present invention and advantage can be become apparent, special embodiment below, and coordinate institute's accompanying drawings to be described in detail below.
Accompanying drawing explanation
Fig. 1 is the block diagram of the embodiment of the present invention.
Fig. 2 is the specific embodiment circuit diagram that the present invention regulates circuit.
Fig. 3 is the still another embodiment circuit diagram that the present invention regulates circuit.
Fig. 4 is the embodiment circuit diagram that the present invention is applied in anti exciting converter.
Fig. 5 is the flow chart that the present invention regulates the method for electric power outputting current.
Specific embodiment
The embodiment of the present invention proposes the device of regulation electric power outputting current, it is possible to quickly follow the output electric current of regulation signal conversion power unit.Can be applicable to LED drive power, it is achieved according to the dutycycle of PWM dim signal, quickly regulate the output electric current of power supply.In order to make the content of this exposure to be easier to understand, the example can actually implemented according to this as the present invention especially exemplified by embodiment below.It addition, all may in place of, graphic and embodiment uses the assembly/component/step of identical label, is to represent same or like parts.
Fig. 1 is the block diagram of the embodiment of the present invention, a kind of device regulating electric power outputting current, including power circuit 10, current regulator 11, regulates circuit 12.Described power circuit 10 includes input Input and output Output, and power circuit 10 accepts the electric energy of input Input and exports from output Output after conversion.Described regulation circuit 12 is sampled the output electric current of output Output of power circuit 10, described regulation circuit 12 is according to regulation its sampled reference of Signal Regulation, the output electric current sampled with regulation, and provide an output current feedback signal to described current regulator accordingly.Described current regulator 11 provides control signal according to current feedback signal for described power circuit, so that its output current following regulation signal changes.
Fig. 2 is the specific embodiment circuit diagram that the present invention regulates circuit.Regulate circuit 22 described in the present embodiment to be specifically made up of the first resistance R1, the second resistance R2 and a switch S1, described first resistance R1 and described switch S1 is in parallel with described second resistance R2 again after connecting, described regulation circuit 22 is connected in the output of described power circuit 20, and the voltage at its two ends is supplied to described current regulator 21 as output current feedback signal.In particular, the present embodiment regulates circuit and receives a PWM regulation signal for controlling to switch turning on and off of S1, the sampled reference of the sample circuit being now made up of resistance R1 and R2, i.e. equivalent sampling resistance value will be followed the dutycycle of PWM regulation signal and changed, and dutycycle is the biggest, and switch time of opening of S1 is the longest, sampled reference is the least, dutycycle is the least, and the time that switch S1 turns off is the longest, and sampled reference is the biggest.When sampled reference changes, its sampled value will change, and the current feedback signal of its output is just followed regulation signal and be there occurs change.Through the control action of current regulator, the output electric current of its power circuit will follow the change in duty cycle of regulation signal.
Fig. 3 is the still another embodiment that the present invention regulates circuit, in the present embodiment, described regulation circuit 32 is made up of the first resistance R1, the second resistance R2 and a switch S1, connect with described second resistance R2 again after described first resistance R1 and described switch S1 parallel connection connection, described regulation circuit 32 is connected in the output of described power circuit 30, and the voltage at its two ends is supplied to described current regulator 31 as output current feedback signal.The present embodiment regulates circuit and receives PWM regulation signal for controlling to switch turning on and off of S1, the sampled reference of the sample circuit being now made up of resistance R1 and R2, i.e. equivalent sampling resistance value also can follow PWM regulation signal dutycycle change, in this figure, dutycycle is the biggest, and the time that switch S1 opens is the longest, sampled reference is the least, dutycycle is the least, and the time that switch S1 turns off is the longest, and sampled reference is the biggest.
In Fig. 4, use anti exciting converter to illustrate as a specific embodiment of power circuit, but the invention is not limited in that any power circuit of anti exciting converter all can use assembly of the invention.The anti exciting converter of the present invention, comprises an isolating transformer T, and anti exciting converter isolation is divided into primary and secondary side.Regulation circuit is connected with primary side winding Np of transformer T after using resistance R1 and resistance R2 parallel connection, sensing flows through the current value Is of primary side winding Np, turn ratio relation indirect according to transformer primary side and secondary current senses the current value flowing through vice-side winding Ns, namely the output electric current of power circuit.Switch S1 conducting, R1 with R2 is in parallel, and the equivalent sampling resistance value of regulation circuit is Rs=R1* R2/(Rs1+Rs2), when switch S1 turns off, and R1 is not in parallel with R2, and the equivalent sampling resistance of regulation circuit is Rs '=R1, and Rs < Rs '.Then, the dutycycle of regulation switch S1 conducting, it is possible to regulation, equivalent sampling resistance value changes between resistance Rs and Rs '.Dutycycle is the least, and equivalent sampling resistance value is the biggest.After the equivalent sampling resistance of regulation circuit increases, circuit current feedback signal Is that current regulator 41 obtains will increase, and current regulator 41 controls to reduce the output electric current of anti exciting converter 40.Regulation circuit 42 also includes the driving control circuit 421 of a control switch S1.Described driving control circuit 421 receives PWM and regulates signal, and is adjusted to be suitable for driving driving voltage Vcs, the described PWM regulation signal 44 controlling switch S1 to be more transferred to described drive circuit 421 through a light-coupled isolation 43.Described current regulator 41 further includes current control circuit 411, current zero-crossing point testing circuit 412 and drive circuit 413, whether described current zero-crossing point testing circuit 412 reaches zero according to current feedback signal Is detection output electric current, if reach zero send open signal give described drive circuit 413, drive switch Q open-minded；Described current control circuit receives current feedback signal Is, the input voltage Vi simultaneously using sampling resistor Rs1 and Rs2 dividing potential drop sampling power circuit input obtains current control reference, and current control circuit controls described current feedback signal Is and reaches the described current control reference described switch Q of shutoff.
In particular, the regulation of the PWM in the present embodiment signal is the PWM dim signal of a LED.Described power circuit 40 is used for driving LED lamp, and according to embodiments of the invention, the dutycycle of PWM dim signal is the biggest, and the output electric current of described power circuit 40 is the least, and its LED lamp driven will be the darkest.
The method of the regulation electric power outputting current that Fig. 5 provides for the present invention, the control method in the present embodiment, including following rate-determining steps:
Step 501: use regulation circuit to receive regulation signal.
Step 502: change the resistance of sampling resistor in regulation circuit according to regulation signal.
Step 503: use electric power outputting current described in described regulation circuit sampling, and output current feedback signal；
Step 504: use current regulator to control the output electric current of described power supply according to output current feedback signal.
In particular, the method that the present invention regulates electric power outputting current is applied to LED light modulation, described regulation signal is the PWM dim signal of LED lamp, PWM dim signal is used to change the equivalent resistance that power circuit exports the sampling resistor of electric current, thus regulate the output electric current of power circuit, change the brightness of LED lamp with this.
In sum, the embodiment of the present invention proposes a kind of apparatus and method regulating electric power outputting current, the technical scheme using the present invention to provide can overcome primary-side-control circuit when secondary output voltage reduces, and secondary current can not get accurate constant current control, the technical problem that secondary current increases occurs.
Although the present invention is disclosed above with embodiment; so it is not limited to the present invention; any art has usually intellectual; without departing from the spirit and scope of the present invention; when making a little change and retouching, therefore protection scope of the present invention is when being as the criterion depending on the defined person of appended claims.
Claims (10)
1. regulate a device for electric power outputting current, including, power circuit, regulation circuit and current regulator, described power circuit has input and output, and it receives input electric energy from input and provides output electric energy at output；The electric current of the output of power circuit described in described regulation circuit sampling, and according to regulation Signal Regulation sampled reference, obtain exporting current feedback signal, output is to current regulator；Described current regulator provides control signal according to output current feedback signal for described power circuit so that regulating signal intensity described in the output current following of power circuit.
A kind of device regulating electric power outputting current the most as claimed in claim 1, it is characterised in that described regulation signal is that the PWM of a change in duty cycle regulates signal.
A kind of device regulating electric power outputting current the most as claimed in claim 1, it is characterised in that described regulation circuit is one can be described sampled reference according to the resistance sampling circuit of described regulation Signal Regulation resistance value, described resistance value.
With described second resistor coupled in parallel after a kind of device regulating electric power outputting current the most as claimed in claim 3, it is characterised in that described regulation circuit includes the first resistance, the second resistance and switch, described first resistance and the series connection of described switch.
A kind of device regulating electric power outputting current the most as claimed in claim 3, it is characterised in that described regulation circuit includes the first resistance, the second resistance and switch, with the second resistant series after described first resistance and described switch in parallel.
6. a kind of device regulating electric power outputting current as described in claim 4 or 5, it is characterised in that the switch of described regulation circuit accepts the control of described PWM regulation signal, it is according to PWM regulation signal conduction and shutoff.
A kind of device regulating electric power outputting current the most as claimed in claim 1, it is characterised in that, described power circuit is an isolated variable circuit, and described regulation circuit connected in series is on the former limit of isolated variable circuit.
A kind of device regulating electric power outputting current the most as claimed in claim 6, it is characterised in that described isolated variable circuit is an anti exciting converter, described regulation circuit is connected with the primary side winding of the isolating transformer of described anti exciting converter.
9. the method regulating electric power outputting current, comprises the steps:
Step one: use regulation circuit to receive regulation signal；
Step 2: change the resistance of sampling resistor in regulation circuit according to regulation signal.
A kind of method regulating electric power outputting current the most as claimed in claim 9, it is characterised in that also comprise the steps:
Step 3: use electric power outputting current described in described regulation circuit sampling, and output current feedback signal；
Step 4: use current regulator to control the output electric current of described power supply according to output current feedback signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510027212.3A CN105873307A (en) | 2015-01-20 | 2015-01-20 | Device and method for adjusting power supply output current |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510027212.3A CN105873307A (en) | 2015-01-20 | 2015-01-20 | Device and method for adjusting power supply output current |
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| CN105873307A true CN105873307A (en) | 2016-08-17 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201510027212.3A Pending CN105873307A (en) | 2015-01-20 | 2015-01-20 | Device and method for adjusting power supply output current |
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101631409A (en) * | 2009-08-20 | 2010-01-20 | 英飞特电子（杭州）有限公司 | Pulse-width modulation (PWM) light-adjusting circuit for light-emitting diode (LED) |
| JP2012152053A (en) * | 2011-01-20 | 2012-08-09 | Murata Mfg Co Ltd | Switching power supply and led illumination device |
| CN103813569A (en) * | 2012-11-09 | 2014-05-21 | 天津达福思科技有限公司 | Driving system for high light illuminating system of electric bicycle |
-
2015
- 2015-01-20 CN CN201510027212.3A patent/CN105873307A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101631409A (en) * | 2009-08-20 | 2010-01-20 | 英飞特电子（杭州）有限公司 | Pulse-width modulation (PWM) light-adjusting circuit for light-emitting diode (LED) |
| JP2012152053A (en) * | 2011-01-20 | 2012-08-09 | Murata Mfg Co Ltd | Switching power supply and led illumination device |
| CN103813569A (en) * | 2012-11-09 | 2014-05-21 | 天津达福思科技有限公司 | Driving system for high light illuminating system of electric bicycle |
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Application publication date: 20160817 |
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