TWI282049B - Over-power protection apparatus for self-excited power converters - Google Patents

Abstract

The present invention proposes an over-power protection apparatus for a self-excited power converter. The over-power protection apparatus comprises a soft-start unit, a regulation unit and a timing unit. The soft-start unit outputs a compensation signal to a PWM unit of the self-excited power converter for controlling the output power of the self-excited power converter. The soft-start unit further couples to the regulation unit. Once there is a short circuit or over-load condition at an output of the self-excited power converter, the regulation unit will drive the soft-start unit to control a switching signal of the PWM unit. Therefore, a pulse width of the switching signal of the PWM unit and the output power of the self-excited power converter are reduced. Meanwhile, the timing unit starts to count. As the over-power condition sustains for longer than a determined period, the timing unit will disable the power output of the self-excited power converter.

Description

1282049 IX. Description of the invention: [Technical field to which the invention pertains] The present invention is an over-power protection device for the _-(4) diagnosing and maintaining the Wei.曰目破式...原[Previous technology] Press, in the current desktop computer power supply: the loss of ground is used to provide a stable adjustment of the wheel power supply μ self + 啦 _ _ _ m contains --- gamma The dynamic pressure device τ2 'where - the secondary circuit contains - the voltage regulator capacitor = upturn Q4, - ground 32, - field rate 有一 a fine one electric lower swing circuit 42 and a blocking capacitor Cb; The side circuit contains the rounding inductance L. - Output capacitor C. , - voltage divider resistor ', - voltage divider resistor ¥ ^ ^ c100 and compensation network 'compensation network contains - compensation power -,, ^, supplement & The filter diode 22, the /wave capacitor CpD, a voltage dividing resistor RP1 and a voltage dividing resistor rP2. The self-excited half-bridge power supply uses a bipolar electric 具有 body with high (four) polarity, Q3 and Q4 and the lower bridge power transistor Q4) as the switching power. The bridge power transistor Q3 and the lower bridge power = body q4 'and the subject device τ] transfer energy from the secondary side to the output side, and the driving method utilizes a driving changer having a current dust collector characteristic. The arrival mode is also called proportional drive (proportiona drive). 7 1282049 The second test of the second door - A map 'Country f knows the self-excited half-bridge type electric test device at the start ::. In conjunction with the self-excited half-bridge power supply shown in the third figure, please select (4) to lose the field-base μ-electro-crystal m vdd_h body 12 and the resistance resistor drive, 2 2 Γ, = line charge. The base current core 5 IP=hfex ^ and the hfe is the current gain of the transistor due to the polarity of the implant-and the polarity of the ^ and 11 Α sensed positive potential, and hfe is the current gain of the transistor, especially the upper bridge power The crystal conversion 2 is a map, which is known as the self-excited half-bridge power supply in the energy gain h / bridge-transistor Q3_piezoelectric crystal, and its current utilization is; έΉ ^A base current 1B can be transferred . Crane mode = T2 self-driven side Yagiyun self-excited drive. The driving variable pressure ratio can be obtained: '舆 舆 职 · · · · Β · Ο Ο 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而 而The pole current Ib, the base current is also relatively large - the secondary current Ip, this kind of machine similar to the positive feedback can make the upper bridge power "body Q3 is fully turned on. With the third riding, the scale switching signal S3 is High 1282049: Bit 'the base current at this time lB3Xhfe>Ip 'The main transformer Τι is the energy transfer to the wheel. In addition, due to the opposite polarity of the winding N22b_iib driving the voltage change $ T2, the network = 11B is the money period potential, the lower bridge god The transistor & cutoff, therefore, - the time of the machine W from the positive end of the voltage regulator capacitor Ci to the upper bridge power transistor Q3, the transformer _ winding is called the shame transformer Τι, and then through the blocking capacitor c = Returning to the end of H poetry Ci, the energy of the input end turns to the output side. 、 In addition, the sensing winding τρ of the ripper τ2 can be used to make the primary side and also detect the wheel current. Parameters and characteristics, so it can be used as a limit = coffee sensor Through the filter (chopper diode 22 and the wave capacitor PD), the overpower detection voltage vPD can be obtained: a sin, heart, (2) the voltage across the winding NllA or NllB; Nu is the winding NllA or N s;曰〇"Group Ν· or N22B; Zb is the wheel-man impedance of the upper-bridge power transistor Q3 and the lower-bridge power-electricity Z q4', after obtaining the power-detection voltage VpD, _ over-excellent power P1 per RP2, can be obtained Over power signal v〇p. Supply of the first picture - '4 test second C picture, is a self-excited self-excited half-bridge power supply two two = ΓΛ road map. # PWM _ 励 simultaneously send Micro Motion Wu Ruhu s2 and Sl At the same time, the transistors Qi and Q2 will be turned on at the same time, and the winding N22A_22B of the drive 2 will be short-circuited. The windings N11A and N11B cannot sense 9 1282049 to generate the drive (4) base current Ib, and the sense winding is also unable to _ primary side. Therefore, 'the upper bridge identification transistor (10) lower bridge identification transistor (10) is cut off, and the 'switching signal M s4 system is low level as shown in the third figure. At this time, the main transformer is T! The energy cannot be transmitted to the output side. For the third meter, please refer to the second D diagram, which is the self-excited half-bridge power supply. Circuit diagram during volume conversion. #p-side controller touches Micro Motion

The bit switching signal S1 turns on the transistor Qi, and the windings N22A and B of the secret driving suspension (9) have the same polarity, and the winding Nim senses a positive potential to produce a recording current & and then passes through the winding N11b^_ winding Np. Make a larger base current | B4 'Because the town bridge power transistor Q4 is fully turned on. As shown in the third figure, the switching signal \ is high level, and the base current IB4xhfe>Ip at this time, the main cage transmits energy to the output side. In addition, since the windings 驱动22Α of the driving transformer D2 are opposite to the polarity of Νιια, the winding Ν11Α induces a negative potential, and the upper bridge transistor q3 is turned off, that is, the switching signal ^ is a low level 'After the bridge Q4 is turned on, the pick The direction of the current W is controlled by the positive-voltage contact capacitor Cb of the voltage-stabilizing capacitor (10), and the sensing winding Np of the transformer 2 is passed through the main transistor, and then passes through the lower-bridge power transistor Q4 and finally to the negative terminal of the voltage-stabilizing capacitor = The energy at the input is transmitted to the output side by the main transformer. The description of the above & the first figure, the conventional self-excited half-bridge power supply PWM control $ 100 is to switch the signal & as the power supply just started the action shouting 'skilled self-excited half The pWM controller of the bridge type power supply can also switch the shouting SA as the start number of the electric secret entertainment, and the switching signal S2 is the low level signal at this time. Guard 1282049 Please refer to the fourth figure together for the circuit diagram of the PWM controller of the conventional self-excited half-bridge power supply. The PWM controller 100 includes a pulse width modulation unit 11A, an error amplifier 120, a comparator 130, and a timer 14A. The pulse width modulation unit 110 further includes two D-type flip-flops 11〇1 and 11〇2, an oscillator 1103, two anti-gates 1104 and 1105, and a comparator 1106. The oscillating device 11 〇 3 is configured to generate a sawtooth wave signal VSAW and a clock signal CLK, the sawtooth wave signal Vsaw can determine the switching frequency of the switching signals S! and S2; the positive terminal of the error amplifier 120 is connected to a reference voltage VR, The negative terminal is connected to the feedback terminal FB, and receives a feedback signal vFB' for outputting a compensation signal Vc〇m; the positive terminal and the negative terminal of the comparator 11〇6 are respectively connected to the output terminal of the error amplifier 120 and the The oscillator n〇3 receives the compensation signal 乂〇^ and the sawtooth wave signal Vsaw, and outputs the result through comparison operation, and then passes through the D-type positive and negative descent Hoi, n〇2 and the anti-gate 11〇4, 11〇 The logic operation of 5 is to output and determine the pulse width of the heart and heart of the switching signal. Based on the consideration of safety (safety), the electric secret device provides over-power. Baowei Road is used to shut down the power and turn the power to protect the power itself and the power system end, to avoid short-circuit and overload malfunction. When the power supply (4) is short-circuited and overloaded, the output current and power will increase a lot, and the number and characteristics of the output current will be increased: the domain current 1p will also increase, and the step-by-step will cause the signal V〇p to be selected. plus.曰丄,: The over-power signal VQp exceeds the critical signal, and the comparator is more than the 乂 乂 比较 比较 比较 比较 比较 比较 比较 比较 比较 比较 比较 比较 比较 比较 比较 比较 比较 比较 比较 比较 比较 比较 比较 比较 比较 比较 比较 比较 比较 2 2 140 140 140 140 140 140 Counting, after a delay time I, the timer, _ wheel out will reach the south level of the lock signal ^jatch, through the protection circuit inside the πna controller π 1282049 so that the purpose of switching signals & Td is In order to avoid the transient change of the load is greater than the reaction time of the dynamic load. When the power supply is short, the output is short _, and the output is V. Decrease 卯 The received feedback signal Vfb is reduced due to the reference voltage 乂 =

And back to the information ^ Tree Dragon V hat New Zealand, limbs, ^ on the vFB age test La vR after the error A | § 12 () amplification, will turn out - a large compensation city VGGM (A) to compare si touch That is, the women and children U has been added as VC0M (A). When the power supply is overloaded, the output power increases. Compensation: 唬VC0M also increases to Vc. The compensation signal Vc and the weave wave signal: SAW through the comparison operation of the comparator 11〇6, and then the D-type positive and negative is 1 rhyme, 1102 and the inverse gate 11〇4, 11〇5 logic operation, will The switching signals s 1 (A) and S2 (4) are output.

The heart is full. The above-mentioned setting delay time causes a malfunction, and the delay time must be shown by the third figure. It can be seen that the switching signal and the pulse width ratio S1 and S2 of the S2 (4) are small, so that a large pulse width is switched. The signal & (4) and the heart (4) 'this will cause the duty cycle of the power transistors Q3 and Q4 to increase, while the main transformer is the voltage at both ends of the voltage vTl will be converted to ντι (Α), and the main transformer is the voltage at both ends 乂The working period of our (8) is greater than the working period of VT1, and this situation will continue until the end of the delay time Td. Since this delay time Td will cause over-power protection to be difficult to control, the components of the power supply must withstand large voltage and current stresses, which can easily cause damage. Therefore, the present invention proposes a self-excited power supply state over-power protection device for the above problem, and therefore, in the self-excited power supply of the over-power protection 12 1282049, the constant current control fish can be achieved. Cycle [invention content] Li and her current limit to solve the above problems. = Di turn to the purpose, is to correct the self-excited Wei supply wire short circuit, overload, the error is reduced by the complement (four), so that the upper and lower bridges of the transistor cycle is reduced, in order to achieve periodic current limit With output power limitation.

The self-exciting Weishen wire over power tilting device comprises a positive starting unit, receiving a self-exciting lion supply-return signal, and generating a supplemental shell for the tiger's self-excited power supply. The pulse-width modulation single-domain switching signal, the switching signal controls the self-excited electric secret output. In addition, the flexible start-up element is connected to the whole unit, and the adjustment unit receives the self-excited power supply for crying one of the power signals and the second critical signal, and the output of the self-excited electric wire is short-circuited. When the overload is greater than the second threshold signal, the adjustment unit 7G drives the flexible start unit, and (4) causes the pulse width modulation unit to modulate the switching signal. - the timing unit 'which receives the over power 峨 and the -th critical signal. When the over power signal is greater than the first threshold ,, the timing unit performs the impurity, and after counting for a period of time, the thief will be corrected and the self-excited electric赖 丝 停 停 停 停 停 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断 断[Embodiment] The fourth picture of the fourth test is the circuit of the controller of the self-excited power supply of the present invention. The over-power protection device (4) of the present invention can be set in the self-excited power supply. The controller 200 is connected to one of the PWM controllers 2, and the pulse width modulation unit of the present invention can also be referred to the controller. The overpower protection device of the present invention comprises a flexible starting unit (10), a timekeeping unit 7G 23G and an adjusting unit 24A. The New Kaixuan element 22仏 contains an operation amplification benefit 2201, #差放大益2202, a clamp diode 22〇3, and a charging unit 'charge single can contain-the first power supply and the start capacitor & The first power source 2204 is connected to the startup capacitor Css to charge the startup capacitor &运=Amplifier 2201 'The positive terminal receives a reference voltage %, while the negative terminal is connected to the negative terminal H 2201's output terminal and the _ 容 容 容 。 。 。 。 。 。 。 。 。 。 When the output terminal outputs the starting voltage %, it has the steady-state side scale stable element; the county discharge A||fiber, the positive end is connected to the output of the under-moving private valley Css 4 The voltage Vss, the terminal of the differential amplification 22202 is connected to the feedback terminal of the self-excited power supply wire, the heating service vFB, the output of the error amplification H fiber is connected to the pulse width „周麦单位210 'Disease amplifier 2202 Receiving the start light Vss and the feedback signal Wb for outputting the compensation signal Vc〇M; the clamp diode 2 is connected between the negative end and the output end of the error amplification a 22G2, and is connected to the self-excited electric The secret device is activated to clamp the voltage level of the compensation signal vC0M. A pulse width modulation unit 21G, which comprises two D-type flip-flops and a hired, a vibrator 2103, two opposite gates and 21〇5, and a comparator eagle, oscillates 14 1282049 2103 for generating - the clock signal CLK and a mine tooth wave age can be used to determine the switching signal Si and & switch switching drunk; the positive end of the comparator 2 touch is connected to the flexible start unit 220 error to the fine end of the fiber, Receiving the compensation signal vC0M, and the negative end is connected to the slitter fine, receiving the weave wave signal v read, and comparing the loss-receiving fruit through the D-type flip-flop, and the anti-gate 2H) The logic operation 'outputs and determines the pulse width of the switching signal & When the self-excited power supply is turned on, the first power supply 22〇4 charges the starting capacitor css and the starting voltage Vss (four) volts starts to rise. Since the operational amplifier 2201 is unity gain, the maximum value of the reference voltage vR is normal. When the positive terminal of the error amplifier 22〇2 is initially zero volt, since the clamp diode 22G3 has the clamp voltage level, the output terminal of the error amplifier 2202 is clamped to the fine voltage of the clamp diode. The % drop is about 0.7V), and then the 'the starting voltage ^ received by the positive terminal of the error amplifier gradually rises, and the compensation signal v_ outputted by the block amplifier 22〇2 is gradually increased, so that the charging pin is over, _峨Si The width of the pulse wave with & will change with the change of the starter battery Vss, and the pulse width of the switching signals S1 and & reaches the preset value, and the self-excited power supply is Output voltage V. It will increase with the gradual rise of the starter Vss, and finally the turn-on voltage V〇 is completely established, thus achieving the function of flexible start. The first-power source 2204 is a current source for starting the self-excited power supply, providing a charging current to the starting capacitor css, causing the starting voltage Vss to gradually rise, and the output voltage of the self-excited power supply. 〇 gradually increased. The start capacitor & 1206049 is used to plan the start-up time of the self-excited power supply, the larger will increase the start-up time, and the capacitance value of the power switch can be reduced' so that the delay time of the start-up can be Within the appropriate range. The first picture of the port is 'review the fifth picture, the timing unit 23〇 contains - the first ratio: the coffee and the - axis fiber, the first - negative end of the first - negative: respectively: the power ΙΚ ν0Ρ and the first - The threshold signal Vthi, and the output of the first comparator is connected to the reset terminal of the timer 2302. When the over-power signal v〇p is lower than the first critical signal VTHI, the output of the first-comparator (four) and the reset terminal of the timer 23〇2 2 are dislocated. The latch signal LATCH sent by the wheel end is low level, and the self-excited power supply is normally operated. When the output of the self-excited power supply is short-circuited or overloaded, the output current and power are greatly increased, and the rib_output current The parameters and the miscellaneous-secondary power = ^ also increase, and the step-by-step causes an over-power signal and increases. When the over-power signal V〇p exceeds the threshold call vTH1, the output end of the first comparator 23〇1 and the reset end of the timer fiber are at a high level, and the scale timing starts counting, and the delay time after the segment Td is ' The latch signal LATCH sent by the output of the timer is high level. After the PWM control (four)_ protection circuit, the upper bridge power transistor 仏 and the lower bridge power transistor Q4 are completely cut off, and the domain voltage ^ Τι cannot be mixed. The amount is output to the output side, that is, the self-excited power supply stops supplying power. Referring to the fifth figure, the adjustment unit 24 includes a second comparator, a second power supply 24G2, and a second-side comparator, and the negative terminal 12 1282049 receives the power signal v〇, respectively. The second power source 24〇2 is connected between the first switch 2403 and a ground, and the first switch 24〇3 is connected to the first power source 2204 and the starting capacitor Css. ...When the output of the self-excited power supply is short-circuited or overloaded, the over-power signal vOP increases. When the over-power signal v〇p exceeds the first critical signal, the timer 2302 starts counting, if the over-power signal v〇 p also exceeds the second critical signal τη2. The second comparator Mo is _ the output is high level, driving the first-off 2403 material pass state, the starting capacitor Css is fixed. The second power source 2402 begins to discharge. Although the first power source 22〇4 is still charging the startup power, the discharge current value of the second power source 2402 is 1〇(^ is much larger than the charging current value ICH of the first power source 2204, thus causing the figure 6 as shown in FIG. The start-up voltage vss is quite fast. Since the self-excited power supply has a certain delay through the feedback, it will cause a short period of time when the over-power signal v〇p exceeds the second critical signal Vth2 as shown in the sixth figure. At this time, the starting voltage Vss drops, and the timer 2302 is still counting j. Relatively, because the starting voltage vss drops, the error amplifier 2 outputs the compensation signal as shown in the seventh figure. It can be seen that the compensation signal VC is less than the level of the compensation signal vC0M, so after the comparison of the comparators 21〇6, it will cause the switch to switch the larger pulse width. The signal Si(9) and S·, which generate the switching signal s and the heart (9) of the smaller pulse wave, cause the working period of the upper bridge power transistor Q3 and the lower bridge power transistor Q4 to be less, reducing the voltage across the main and the AC voltage A. VT1 (B} work cycle, making The over-power signal v〇p drops 0 17 1282049 When the over-power 峨, lower _ is lower than the second critical signal %, the start-up action of the start-up valley css ends. 'Start-up power vsss maintains at a lower voltage level: At this time, since the over-power signal v〇p is still higher than the first-critical signal VTH1, the timing a 2302 is still counting 'when the over-power signal I ΟΡ ΟΡ falls below the second critical signal VTH2, the second comparator 2401 To disable, the first switch 24〇3 is in an off state. At this time, the first power supply 2204 starts to charge the startup capacitor & then, the startup voltage VSS starts to rise slowly from a lower voltage level. The increase of % easing k causes the duty cycle of the upper bridge power transistor A and the lower bridge power transistor (3) to increase slowly, causing the ecstasy signal Vqp to exceed the second critical signal v. Then, the second comparator is fine. The output terminal is at a high level, and the first switch lake is in a conducting state. The starting capacitor Css starts to discharge again with the fixed second power fiber. Thus, the charging and discharging operation of the repeated cycle is performed until after a delay time I, the output of the timer 2302 The latch signal Latch sent by the terminal is at a high level, and the PWM control (4) _ depends on the upper bridge power crystal Q3 and the lower bridge power transistor Q4. • The output of the self-excited power supply is short-circuited. When the power-off waste Vo drops, the feedback signal Vfb received by the feedback terminal FB decreases, and the compensation signal Vc〇M also increases. When the overload occurs from the left-excited power supply, the output power increases, and the compensation signal increases. The increase of the 乂 级 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 Just give the comparator fiber, that is, the tiger vC0M is reduced to Vc〇m(b). Compensation signal % Qing) and the mine window wave signal Vsaw through the comparator 鸠, D-type flip-flop 2m, and the reverse 2, measured 18 1282049 twinning pulse width switching signals S and s, resulting in ^ (four) The duty cycle of the day body q3 and the lower bridge power transistor (3) is reduced, and the working example delay time Td of the voltage v across the main voltage regulator 结束1 ends. The period of _ is reduced and the continuation depends on the mechanism of power protection due to this delay time Td, the same current limit and maximum turn-off power limit. Through the over-power preservation of the present invention, it is possible to avoid the compensation signal VC0M which is excessively high when the self-excited Wei wire is read out, and the output power of the self-excited power supply is increased, and in the case of the invention, the upper bridge Power transistor _ lower bridge power transistor and current rating are lower, the circuit cost can also be turned down. In the fifth diagram, the adjustment unit further includes a second switch, the basin is connected between the starting capacitor Css and the ground, and the second switch 2404 and the start # CSS are connected to the system.跋, used to discharge the starting capacitor line. The self-excited f source supply unit does not provide the output function. The unit 220 detects the feedback signal VFB from the feedback terminal FB, and passes through the internal protection circuit to output the reset signal.

RST. The enable of the reset signal RST can cause the start capacitor Css to be quickly discharged, causing the start voltage Vss to quickly cause the level of the compensation signal VC0M to drop. - Because the compensation signal VC0M is rapidly reduced, the compensation signal VC0M and the ore tooth VSAW are compared by the brain of the comparator 2, so that the output of the very small pulse two switching signal 'will cause the upper bridge power transistor & and the lower bridge power transistor see Second, the cycle is reduced, that is, the duty cycle of the main transformer terminal voltage is reduced. 4 = dynamic voltage vss continues to drop, and the compensation signal Vc〇m also drops below the mineral tooth wave: No. 19 1282049

When Vsaw's transistor Q! and Q2 are fully turned on, the upper bridge power transistor & and the lower bridge power transistor Q4^ are finished, because of the resetting _ when the art care effect: In summary, the present invention proposes An over-power protection shock is used in the self-excited power supply H towel. When the input terminal is short-circuited and overloaded, the unit can be lowered by adjusting the unit to reduce the pressure. In this way, the power of the upper bridge power (4) and the jade of the lower bridge can be reduced and reduced.

= The period of the voltage across the voltage regulator, so that the maximum output power limit can be reached periodically. The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention to the extent that the present invention is based on the shape of the present invention. Changes and modifications should be clearly stated in the patent application. Knowledge

20 1282049 £Simple description of the schema] The first diagram is the conventional self-excitation + the second A diagram is the conventional self-excited circuit diagram; the road diagram; the σ甩源, the circuit diagram of the electric power during the start-up period·· (10) for the self-excited self-excited half-bridge power supply 11 during the energy conversion process. The second C_ is the electrical power of the conventional self-excited half-bridge power supply during the flywheel, which is a self-excited half. The bridge type power supply 11 during the energy conversion period A is the waveform diagram of the self-excited half-bridge type electric wire, the switching signal and the voltage across the main transformer M; ° circuit = picture system A diagram of a PWM controller of a self-excited half-bridge type power supply; a fifth circuit of a lingering self-excited singular supply of PWM (four) 第六 a sixth _ is a self-excited electric secret of the present invention Waveform diagram of the starting voltage vss and the overpower signal v〇p; The seventh figure is a waveform diagram of the ore wave signal, the compensation signal, the switching signal and the rain terminal voltage of the main transformer of the self-excited power supply of the present invention. [Main component symbol description] 12 diode 22 filter diode 1282049

32 upper bridge drive circuit 42 lower bridge drive circuit 100 PWM controller 110 pulse width modulation unit 1101 D type flip-flop 1102 D type flip-flop 1103 oscillator 1104 reverse gate 1105 reverse gate 1106 comparator 120 error amplifier 130 Comparator 140 Timer 200 PWM Controller 210 Pulse Width Modulation Unit 2101 D-Type Reactor 2102 D-Type Reactor 2103 Oscillator 2104 Inverting Gate 2105 Inverting Gate 2106 Comparator 22 1282049

220 flexible start unit 2201 operational amplifier 2202 error amplifier 2203 clamp diode 2204 first power supply 230 timing unit 2301 first comparator 2302 timer 240 adjustment unit 2401 second comparator 2402 second power supply 2403 first switch 2404 second Switch C〇 Output Capacitor Ci Regulator Capacitor C2 Regulator Capacitor CB Barrier Capacitor Cc Compensation Capacitor CpD Filter Capacitor Css Start Capacitor CLK Clock Signal 23 1282049

Ib base current Ip primary side current Νπα winding Nub winding N22A winding N22B winding NP sensing winding Qi transistor Q2 transistor q3 upper bridge power transistor q4 lower bridge power transistor L〇 output inductor R〇i voltage divider resistor R〇 2 Voltage divider resistor Rc Compensation resistor Rd Resistance Rpi Divider resistor Rp2 Divider resistor Si Switching signal Sl(A) Switching signal Sl(B) Switching signal 24 1282049 S2 Switching signal S2(A) Switching signal S2(B) Switching signal S3 Switching signal S3 (A) Switching signal S3 (B) Switching signal s4 Switching signal S4 (A) Switching signal S4 (9) Switching signal Tl Main transformer T2 Driving transformer Vc〇M Compensation signal

Vc〇M(A) Compensation signal Vc〇M(B) Compensation signal vDD Supply voltage Vfb Feedback signal VPD Over power detection voltage V〇 Output voltage V〇p Over power signal Vr Reference voltage Vs AW Sawtooth signal Vss Start voltage 25 1282049 ντ VT1 Vti(a) Vti(9) Vthi Vth2 critical signal main transformer voltage across the main transformer voltage across the main transformer voltage first critical signal second critical signal

Claims (1)

1282049 X. Patent application scope: 1. An over-power protection device for a self-excited power supply, comprising: a flexible starting unit, receiving a feedback signal of the self-excited power supply, generating a compensation signal for a pulse width modulation unit of the self-excited power supply unit generates a switching signal, the switching signal controls the power output by the self-excited power supply; an adjusting unit coupled to the flexible starting unit, the adjusting unit receives the One of the self-powered power supply has an over-power signal and a second threshold signal. When the over-power signal is greater than the second threshold signal, the adjusting unit drives the flexible starting unit to drive the pulse width modulation unit to modulate the Switching the signal to reduce the output of the self-excited power supply; and a timing unit receiving the over-power signal of the self-excited power supply and a first g-product boundary, the over-power signal being greater than the first When a critical signal is used, the timing unit counts, and after counting for a period of time, a lock signal is sent to stop the self-excited power supply. Should be powered. 2. The overpower protection device of the self-excited power supply device of claim 1, wherein the flexible starting unit further comprises: a charging unit that generates a starting voltage; and a voltage stabilizing unit coupled to the charging a unit for stabilizing the voltage; an error amplifier having a positive terminal coupled to the charging unit and the voltage stabilizing unit, receiving 27 1282049, the starting voltage 'problem amplification red negative termination _ self-excited f source supply The feedback signal, the output terminal of the error amplifier outputs the compensation signal; and the clamp diode 'couples between the output end and the negative end of the error amplifier. 3. For example, the self-excited Weishen over-power protection device described in Item 2 of the application, the miscellaneous pressure unit can be a unit gain buffer unit, which can be an operational amplifier. Positive terminal receiving-reference electrical calendar, the negative terminal of the operational amplifier _ at the output end and the charging unit receives the starting voltage, and the output terminal of the operational amplifier is connected to the positive terminal of the error amplifier. 4. The overpower protection device of the self-excited power supply device of claim 2, wherein the charging unit comprises a first power source and a starting capacitor, and the first power source is coupled to the starting capacitor 'The startup voltage is generated for the startup capacitor domain. Lu 5·, as described in claim 2, the self-excited power supply wire over-power protection description, wherein the flexible start-up unit is driven to drive the pulse width modulation unit to adjust the switching §fL The second adjustment unit is coupled to: a second power source coupled to the ground; a first switch coupled between the charging unit and the second power source; and a second comparator The positive end and the negative end respectively receive the 5 过 power 吼 and the second critical signal of the self-excited power supply, and the over power signal is greater than the second 28 1282049 critical signal when the second comparator outputs The terminal outputs a signal to drive the first switch to conduct 'discharge the charging unit to lower the starting voltage. 6. The over-power protection of the self-excited power supply as described in claim 5 of the patent scope - wherein the adjustment unit further comprises a second switch, the system is connected to the ground Between the second and second receiving-resetting signals, the charging unit is turned on to discharge the starting voltage. Lu 7. For the towel, please refer to the self-excited electric test described in the article, which should be red over the power protection device. The timing unit includes a first comparator and a timer, the comparator and the timer. Receiving, the positive end and the negative end of the first taste phase are received by the self-excited source and the first critical gas number is greater than the first critical signal. The first - than the normal wheel ^ high level signal to the timer, so that the timer counts. Then, the application of the self-excited power supply of the self-excited power supply described in the above-mentioned patents is as follows: • The adjustment is performed when the 5th adjustment meter 70 receives the over-power signal greater than the second threshold ^ The unit drives the flexible starting unit, and (10) the compensation signal: bit to reduce the output of the self-excited power supply. / 9.= Please refer to the self-excited power supply device of the patent range mentioned in item 1. The PWM controller can be set in one of the self-excited power supply. μ 29