CN203352434U - Power supply voltage control circuit - Google Patents
Power supply voltage control circuit Download PDFInfo
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- CN203352434U CN203352434U CN 201320292615 CN201320292615U CN203352434U CN 203352434 U CN203352434 U CN 203352434U CN 201320292615 CN201320292615 CN 201320292615 CN 201320292615 U CN201320292615 U CN 201320292615U CN 203352434 U CN203352434 U CN 203352434U
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- 239000003990 capacitor Substances 0.000 claims abstract description 62
- 239000004230 Fast Yellow AB Substances 0.000 claims abstract description 29
- 239000004231 Riboflavin-5-Sodium Phosphate Substances 0.000 claims abstract description 15
- 230000001681 protective effect Effects 0.000 claims description 13
- 239000003381 stabilizer Substances 0.000 claims description 11
- 238000004146 energy storage Methods 0.000 abstract description 2
- 238000010521 absorption reaction Methods 0.000 abstract 1
- 238000004804 winding Methods 0.000 description 16
- 230000000694 effects Effects 0.000 description 6
- 238000000034 method Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- 208000032365 Electromagnetic interference Diseases 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
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Abstract
The utility model discloses a power supply voltage control circuit, including starting voltage input VIN, mains voltage output Vo, starting resistance, energy storage capacitor E106, isolating circuit D108, stabilivolt ZD101, protection resistance R128, transformer, rectifier diode D107, filter capacitor E105, additional load circuit and chip U1; the RC absorption circuit is connected with the rectifying diode D107 in parallel, the additional load circuit is connected with the filter capacitor E105 in parallel, and a power supply pin of the chip U1 is connected with the power supply voltage output end Vo. The utility model discloses can solve under the light no-load condition of flyback converter, supply voltage is on the low side, full-load and the big problem of no-load VCC voltage differential pressure, and when solving and relying on chip overvoltage protection, the higher problem of overvoltage protection point.
Description
Technical field
The utility model relates to electronic technology field, relates in particular to a kind of source voltage control circuit.
Background technology
Reverse exciting switching voltage regulator VCC voltage control circuit is generally used for to chip power supply, mainly by starting power supply, starting resistance, storage capacitor, transformer VCC winding, filter capacitor and buffer circuit, forms.Wherein, this circuit is for to PWM(Pulse Width Modulation, pulse width modulation) operation principle of control chip power supply is as follows:
During the machine of rising, start power supply and charge to storage capacitor by starting resistance, when the voltage on storage capacitor reaches the cut-in voltage of chip, chip is started working, output pwm signal.Transformer VCC winding starts to charge to filter capacitor, when the voltage on filter capacitor is greater than the voltage on storage capacitor, the buffer circuit conducting, transformer VCC winding starts to provide electric current to chip via buffer circuit, the required energy of chip operation now, mainly from transformer VCC winding.
There is following shortcoming in existing reverse exciting switching voltage regulator VCC voltage control circuit: under the light idle condition of anti exciting converter, supply voltage is on the low side, fully loaded large with unloaded VCC voltage pressure reduction; When relying on the chip overvoltage protection, over-voltage protection point is higher.
Summary of the invention
The utility model proposes a kind of source voltage control circuit, can solve under the light idle condition of anti exciting converter, supply voltage is on the low side, the fully loaded and large problem of unloaded VCC voltage pressure reduction, and solve while relying on the chip overvoltage protection problem that over-voltage protection point is higher.
The utility model provides a kind of source voltage control circuit, comprises starting resistor input VIN, supply voltage output end vo, starting resistance, storage capacitor E106, buffer circuit D108, voltage-stabiliser tube ZD101, protective resistance R128, transformer, rectifier diode D107, filter capacitor E105, additional load circuit and chip U1;
One end of described starting resistance is connected with described starting resistor input VIN, and the other end of described starting resistance is connected with described supply voltage output end vo; Described supply voltage output end vo also is connected with the positive pole of described storage capacitor E106, the minus earth of described storage capacitor E106;
The load-side of described transformer has two terminals, one of them terminal ground connection, another terminal is connected with the positive pole of described rectifier diode D107, and the negative pole of described rectifier diode D107 is connected with the positive pole of described filter capacitor E105, the minus earth of described filter capacitor E105;
The end of described protective resistance R128 is connected with the negative pole of described rectifier diode D107, and the end of the other end of described protective resistance R128 and described voltage-stabiliser tube ZD101 is connected, the other end ground connection of described voltage-stabiliser tube ZD101; The other end of described protective resistance R128 also is connected with the input of described buffer circuit D108, and the output of described buffer circuit D108 is connected with described supply voltage output end vo;
Described additional load circuit and described filter capacitor E105 parallel connection, the power pins of described chip U1 is connected with described supply voltage output end vo.
One preferred embodiment in, described additional load circuit comprises the first resistance R 125; One end of described the first resistance R 125 is connected with the positive pole of described filter capacitor E105, the other end ground connection of described the first resistance R 125.
Another preferred embodiment in, described additional load circuit comprises the first resistance R 125, the second resistance R 126, the 3rd resistance R 129 and NPN type triode Q221;
One end of described the first resistance R 125 is connected with the positive pole of described filter capacitor E105, and the other end of described the first resistance R 125 is connected with the collector electrode C of described NPN type triode Q221;
One end of described the second resistance R 126 is connected with the positive pole of described filter capacitor E105, and the other end of described the second resistance R 126 is connected with the base stage B of described NPN type triode Q221;
One end of described the 3rd resistance R 129 is connected with the base stage B of described NPN type triode Q221, the other end ground connection of described the 3rd resistance R 129;
The emitter E ground connection of described NPN type triode Q221.
The source voltage control circuit that the utility model embodiment provides, an additional load circuit in parallel on the filter capacitor of transformer VCC winding, this additional load circuit can consume the unnecessary energy that the VCC winding passes over, and allows full load VCC voltage not be elevated; During light zero load, the VCC voltage ratio is lower, and the energy Ratios of this additional load circuitry consumes is less, thereby reaches the purpose of adjusting VCC voltage, and to solve under the light idle condition of anti exciting converter, supply voltage is on the low side, the fully loaded and large problem of unloaded VCC voltage pressure reduction.In addition; the additional load circuit is in the process of work; the energy the VCC winding not passed over is hindered, so the voltage on filter capacitor rises than very fast, when output overvoltage; VCC voltage is promoted rapidly; reach soon the protection point of VCC voltage, chip quits work, thereby makes output overvoltage point lower; while to solve, relying on the chip overvoltage protection, the problem that over-voltage protection point is higher.
The accompanying drawing explanation
Fig. 1 is the structural representation of an embodiment of the source voltage control circuit that provides of the utility model;
Fig. 2 is the structural representation of another embodiment of the source voltage control circuit that provides of the utility model.
Embodiment
Below in conjunction with the accompanying drawing in the utility model embodiment, the technical scheme in the utility model embodiment is clearly and completely described.
Referring to Fig. 1, it is the structural representation of an embodiment of the source voltage control circuit that provides of the utility model.
The present embodiment provides a kind of source voltage control circuit, comprises starting resistor input VIN, supply voltage output end vo, starting resistance, storage capacitor E106, buffer circuit D108, voltage-stabiliser tube ZD101, protective resistance R128, transformer, rectifier diode D107, filter capacitor E105, additional load circuit and chip U1.Specific as follows:
One end of described starting resistance is connected with described starting resistor input VIN, and the other end of described starting resistance is connected with described supply voltage output end vo; Described supply voltage output end vo also is connected with the positive pole of described storage capacitor E106, the minus earth of described storage capacitor E106;
The load-side of described transformer has two terminals, one of them terminal ground connection, another terminal is connected with the positive pole of described rectifier diode D107, and the negative pole of described rectifier diode D107 is connected with the positive pole of described filter capacitor E105, the minus earth of described filter capacitor E105;
The end of described protective resistance R128 is connected with the negative pole of described rectifier diode D107, and the end of the other end of described protective resistance R128 and described voltage-stabiliser tube ZD101 is connected, the other end ground connection of described voltage-stabiliser tube ZD101; The other end of described protective resistance R128 also is connected with the input of described buffer circuit D108, and the output of described buffer circuit D108 is connected with described supply voltage output end vo;
Described additional load circuit and described filter capacitor E105 parallel connection, the power pins of described chip U1 is connected with described supply voltage output end vo.
In the present embodiment, described additional load circuit comprises the first resistance R 125; One end of described the first resistance R 125 is connected with the positive pole of described filter capacitor E105, the other end ground connection of described the first resistance R 125.It should be noted that, described the first resistance R 125 is single independently resistance, or the connection in series-parallel assembly of a plurality of resistance.When resistor power does not meet the demands, many resistance can be on filter capacitor E105 in parallel.
In an optional execution mode, described buffer circuit D108 comprises diode; The positive pole that the input of described buffer circuit D108 is described diode, the negative pole that the output of described buffer circuit D108 is described diode.
Above-mentioned starting resistance is single independently resistance, or the connection in series-parallel assembly of a plurality of resistance.For example, as shown in Figure 1, starting resistance is composed in series by resistance R 112, resistance R 114 and resistance R 119.
Further, the source voltage control circuit that the present embodiment provides also comprises the RC absorbing circuit; Described RC absorbing circuit and described rectifier diode D107 parallel connection.
Above-mentioned RC absorbing circuit comprises the first capacitor C 104 and the 4th resistance R 124; One end of described the first capacitor C 104 is connected with the positive pole of described rectifier diode D107, the other end of described the first capacitor C 104 is connected with an end of described the 4th resistance R 124, and the other end of described the 4th resistance R 124 is connected with the negative pole of described rectifier diode D107.
In another optional execution mode, described chip is pulse width modulation (Pulse Width Modulation is called for short PWM) control chip, or other control IC.
The described chip of below only take is example as PWM controls IC, and the operation principle of the source voltage control circuit that the utility model is provided is elaborated.
Resistance R 112, resistance R 114 and resistance R 119 form starting resistance.During the machine of rising, starting resistor input VIN inputs starting resistor, and by starting resistance, to storage capacitor E106 charging, when the voltage on storage capacitor E106 reaches the cut-in voltage of chip U1, chip U1 starts working, output pwm signal.Transformer VCC winding starts to charge to filter capacitor E105, when the voltage on filter capacitor E105 is greater than the voltage on storage capacitor E106, the VCC winding starts to provide electric current to chip U1, and the chip U1 required energy of working now, mainly from transformer VCC winding.
Below the effect of each device in Fig. 1 is elaborated:
Chip U1 is that PWM controls IC, is the load of supply voltage circuit, and wherein the 5th pin is power pins; IC model difference, power pins may be different.
Storage capacitor E106 is for energy storage, and during start, the voltage on electric capacity E106 reaches the cut-in voltage of chip U1, and chip U1 starts working.
Buffer circuit D108 plays the effect of isolation, when start, can stop starting current to flow to electric capacity E105 upper, thereby accelerate the machine time.
Voltage-stabiliser tube ZD101 can play the effect of protection IC.
Protective resistance R128 plays the effect of protection voltage-stabiliser tube ZD101.
Filter capacitor E105 is the filter capacitor of VCC winding.
Rectifier diode D107 plays the effect of rectification.
The RC absorbing circuit is comprised of the first capacitor C 104 and the 4th resistance R 124, can reduce due to voltage spikes, simultaneously to processing EMI(Electro Magnetic Interference, electromagnetic interference) also beneficial.
It is upper that the first resistance R 125 is connected in parallel on filter capacitor E105, is used for consuming the unnecessary energy that transformer VCC winding passes over, and allows full load VCC voltage not be elevated; Due to VCC voltage when the heavy duty, voltage ratio is higher, so the energy comparison that the first resistance R 125 consumes is many, during the light zero load of voltage, the VCC voltage ratio is lower, and the energy Ratios that the first resistance R 125 consumes is less, thereby reach the purpose of adjusting VCC voltage, to solve under the light idle condition of anti exciting converter, supply voltage is on the low side, the fully loaded and large problem of unloaded VCC voltage pressure reduction.In addition; the first resistance R 125 is in the process of work; the energy the VCC winding not passed over is hindered, so the voltage on filter capacitor rises than very fast, when output overvoltage; VCC voltage is promoted rapidly; reach soon the protection point of VCC voltage, chip U1 quits work, thereby makes output overvoltage point lower; while to solve, relying on the chip overvoltage protection, the problem that over-voltage protection point is higher.
Referring to Fig. 2, it is the structural representation of another embodiment of the source voltage control circuit that provides of the utility model.
With the source voltage control circuit of above-mentioned Fig. 1, compare, the distinctive points of the source voltage control circuit that the present embodiment provides is, described additional load circuit comprises the first resistance R 125, the second resistance R 126, the 3rd resistance R 129 and NPN type triode Q221; One end of described the first resistance R 125 is connected with the positive pole of described filter capacitor E105, and the other end of described the first resistance R 125 is connected with the collector electrode C of described NPN type triode Q221; One end of described the second resistance R 126 is connected with the positive pole of described filter capacitor E105, and the other end of described the second resistance R 126 is connected with the base stage B of described NPN type triode Q221; One end of described the 3rd resistance R 129 is connected with the base stage B of described NPN type triode Q221, the other end ground connection of described the 3rd resistance R 129; The emitter E ground connection of described NPN type triode Q221.
The second resistance R 126, the 3rd resistance R 129 and the NPN type triode Q221 that in source voltage control circuit, increase, be mainly used in reducing zero load and waste.By reasonably regulating the resistance of the second resistance R 126 and the 3rd resistance R 129, allow NPN type triode Q221 not conducting under light idle condition, thereby reduced zero load, waste.This circuit is applicable to zero load is wasted to the high occasion of requirement.
The effect of each device in the operation principle of the source voltage control circuit that the present embodiment provides and circuit, identical with the source voltage control circuit of above-mentioned Fig. 1, at this, no longer describe in detail.
The source voltage control circuit that the utility model embodiment provides, an additional load circuit in parallel on the filter capacitor of transformer VCC winding, this additional load circuit can consume the unnecessary energy that the VCC winding passes over, and allows full load VCC voltage not be elevated; During light zero load, the VCC voltage ratio is lower, and the energy Ratios of this additional load circuitry consumes is less, thereby reaches the purpose of adjusting VCC voltage, and to solve under the light idle condition of anti exciting converter, supply voltage is on the low side, the fully loaded and large problem of unloaded VCC voltage pressure reduction.In addition; the additional load circuit is in the process of work; the energy the VCC winding not passed over is hindered, so the voltage on filter capacitor rises than very fast, when output overvoltage; VCC voltage is promoted rapidly; reach soon the protection point of VCC voltage, chip quits work, thereby makes output overvoltage point lower; while to solve, relying on the chip overvoltage protection, the problem that over-voltage protection point is higher.
The above is preferred implementation of the present utility model; it should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the utility model principle; can also make some improvements and modifications, these improvements and modifications also are considered as protection range of the present utility model.
Claims (9)
1. a source voltage control circuit, it is characterized in that, comprise starting resistor input VIN, supply voltage output end vo, starting resistance, storage capacitor E106, buffer circuit D108, voltage-stabiliser tube ZD101, protective resistance R128, transformer, rectifier diode D107, filter capacitor E105, additional load circuit and chip U1;
One end of described starting resistance is connected with described starting resistor input VIN, and the other end of described starting resistance is connected with described supply voltage output end vo; Described supply voltage output end vo also is connected with the positive pole of described storage capacitor E106, the minus earth of described storage capacitor E106;
The load-side of described transformer has two terminals, one of them terminal ground connection, another terminal is connected with the positive pole of described rectifier diode D107, and the negative pole of described rectifier diode D107 is connected with the positive pole of described filter capacitor E105, the minus earth of described filter capacitor E105;
The end of described protective resistance R128 is connected with the negative pole of described rectifier diode D107, and the end of the other end of described protective resistance R128 and described voltage-stabiliser tube ZD101 is connected, the other end ground connection of described voltage-stabiliser tube ZD101; The other end of described protective resistance R128 also is connected with the input of described buffer circuit D108, and the output of described buffer circuit D108 is connected with described supply voltage output end vo;
Described additional load circuit and described filter capacitor E105 parallel connection, the power pins of described chip U1 is connected with described supply voltage output end vo.
2. source voltage control circuit as claimed in claim 1, is characterized in that, described additional load circuit comprises the first resistance R 125; One end of described the first resistance R 125 is connected with the positive pole of described filter capacitor E105, the other end ground connection of described the first resistance R 125.
3. source voltage control circuit as claimed in claim 1, is characterized in that, described additional load circuit comprises the first resistance R 125, the second resistance R 126, the 3rd resistance R 129 and NPN type triode Q221;
One end of described the first resistance R 125 is connected with the positive pole of described filter capacitor E105, and the other end of described the first resistance R 125 is connected with the collector electrode C of described NPN type triode Q221;
One end of described the second resistance R 126 is connected with the positive pole of described filter capacitor E105, and the other end of described the second resistance R 126 is connected with the base stage B of described NPN type triode Q221;
One end of described the 3rd resistance R 129 is connected with the base stage B of described NPN type triode Q221, the other end ground connection of described the 3rd resistance R 129;
The emitter E ground connection of described NPN type triode Q221.
4. source voltage control circuit as claimed in claim 2 or claim 3, is characterized in that, described the first resistance R 125 is single independently resistance, or the connection in series-parallel assembly of a plurality of resistance.
5. source voltage control circuit as described as the claims 1 to 3 any one, is characterized in that, described buffer circuit D108 comprises diode; The positive pole that the input of described buffer circuit D108 is described diode, the negative pole that the output of described buffer circuit D108 is described diode.
6. source voltage control circuit as described as the claims 1 to 3 any one, is characterized in that, described starting resistance is single independently resistance, or the connection in series-parallel assembly of a plurality of resistance.
7. source voltage control circuit as described as the claims 1 to 3 any one, is characterized in that, described source voltage control circuit also comprises the RC absorbing circuit; Described RC absorbing circuit and described rectifier diode D107 parallel connection.
8. source voltage control circuit as claimed in claim 7, is characterized in that, described RC absorbing circuit comprises the first capacitor C 104 and the 4th resistance R 124;
One end of described the first capacitor C 104 is connected with the positive pole of described rectifier diode D107, the other end of described the first capacitor C 104 is connected with an end of described the 4th resistance R 124, and the other end of described the 4th resistance R 124 is connected with the negative pole of described rectifier diode D107.
9. source voltage control circuit as described as the claims 1 to 3 any one, is characterized in that, described chip U1 is the pulse width modulation control chip.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320292615 CN203352434U (en) | 2013-05-27 | 2013-05-27 | Power supply voltage control circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320292615 CN203352434U (en) | 2013-05-27 | 2013-05-27 | Power supply voltage control circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203352434U true CN203352434U (en) | 2013-12-18 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201320292615 Expired - Lifetime CN203352434U (en) | 2013-05-27 | 2013-05-27 | Power supply voltage control circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN203352434U (en) |
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2013
- 2013-05-27 CN CN 201320292615 patent/CN203352434U/en not_active Expired - Lifetime
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| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20131218 |