CN2691189Y - TV set power circuit having soft starting - Google Patents

Abstract

The utility model relates to a TV power circuit. The power circuit is a TV power circuit with a soft start. The utility model comprises a stably controlled regulating circuit directly sampling from switch regulated power supply. The stable controlled regulating circuit also comprises a soft switch which is connected in series between the output end of a transistor A3 and the ground. The utility model delays the magnitude of voltage time of the main stable magnitude of voltage rising from the low-voltage value to the normal work homeostasis when the TV is changed into the normal work state from the opening starting state or the standing by state. The opening surge attacking passing flow endanger of the rectification filtering return circuit of the respective output ends of the switch stable voltage power source can be lightened. The utility model can prolong the service life of a diode and a capacitor, and is favorable to eliminate the impulsive sound of opening and closing the TV.

Description

Television power circuit with soft start

[technical field]

The utility model relates generally to TV technology, relates in particular to the power circuit of television set.

[background technology]

The all unsuitable frequent on/off picture tube CRT (particularly filament) of prior art, colour TV.Otherwise the accelerated ageing picture tube life-span.See TV in family, be reluctant to see advertisement or be busy with other thing midway, look aside TV or think to listen separately television acoustics,, usually television set is turned off, be easy to damage picture tube and electric power system like this for the energy-conservation picture tube that do not injure again.For addressing this problem, proposed " screen protection " or " listening separately " function, but when starting " screen protection " or " listening separately " function, field scan, decoding circuit and CRT circuit are still in work.Only contrast and brightness are transferred to minimum value.Power consumption is not obviously slowed down.Harm is more: horizontal output stage superhigh pressure more can rise to maximum in screen protection or when listening separately, and easier moisture absorption causes high voltage arc even baked wheaten cake machine fault takes place.Though long-time " listening separately " can accomplish to cut off horizontal output stage, the littler advantage of power consumption.But cause frequency to raise during owing to undue underloading of normal operating conditions power supply or zero load and produce the serious phenomenon of generating heat.Fragile power supply and unfavorable to picture tube, unless increase new " listening separately " power supply in addition, but need increase cost, no producer uses].Because colour TV electric power system rectification filtering circuit, the surge impact overcurrent is very big in opening process, harm diode and capacitor.Prior art does not add effective Current limited Control and sequencing control to this.Particularly when standby transfers operate as normal to, horizontal output stage H.OUT voltage supplied value is risen to the stationary value time and always is ahead of line scanning prime voltage supplied and rises to stationary value by low.When line scanning prime voltage supplied does not reach normally should need under the lower state work time, easily cause the row energization deficiency, fragile line output valve.And be subject to high potential assembly during machine open/close and produce high pressure harm.

[summary of the invention]

Main purpose of the present utility model is exactly in order to solve the problem of television set surge impact in opening process in the prior art, a kind of television power circuit with soft start to be provided.

For achieving the above object, the utility model proposes a kind of television power circuit with soft start, comprise steady control regulating circuit from the switching power supply direct sample, the input stage that described steady control regulating circuit is transistor A3 is got and is come from Switching Power Supply or pressure swing type Switching Power Supply, reference level connects power supply+B and ground connection respectively by the divider resistance branch road, also comprise soft switch in the described steady control regulating circuit, described soft switch series is associated between the output and ground of transistor A3.

Preferably, described soft switch comprises one group of capacitor C that is in parallel 32 and diode W3, and the negative pole of described diode W3 connects the output of transistor A3, plus earth.

Described capacitor C 32 is an electrochemical capacitor, and the negative pole of anodal and described diode W3 is connected, the minus earth of described electrochemical capacitor.

Described diode W3 is the voltage stabilizing didoe of a voltage stabilizing didoe or two series connection.

The beneficial effects of the utility model are: surely control in the regulating circuit (ASE) in the switching power supply direct sample, increase and be parallel to voltage-reference diode W3 two ends soft start capacitor C32, when starting up or standby transfer operate as normal to, delaying main steady magnitude of voltage is raised to the operate as normal stable state and should needs the magnitude of voltage time by low voltage value is slow, just can alleviate each output rectification filtering circuit of switching power supply and open the harm of surge impact overcurrent, prolong diode and life of capacitors, and offset except that the switching on and shutting down impulsive sound favourable.

In order to realize that the user both can be easy to use energy-conservation, need not frequent standby again as far as possible, the utility model includes the interface circuit that links to each other with pause function.Have and can listen television acoustics separately, and the power supply of double soft start horizontal output stage, picture tube benefit in useful life prolonged.With usual standby, " screen protection ", " listen " function not to be both separately: when the utility model suspends, line scanning is still in work, should the value of need but must the steady magnitude of voltage of control switching master fall to automatically, guarantee that horizontal output stage superhigh pressure is that 0 blank screen state ratio drops on the contrary when image is arranged and is the low voltage phenomenon at the picture tube line, alleviates the superhigh pressure moisture absorption and causes the high voltage arc fault.When entering the innovation pause function, sequential is: after screen apparent " no signal or pressure blank screen economize on electricity noise elimination " character shows earlier, force blank screen indicator light HL3 bright again, and shutoff Video Decoder, video amplifier circuit and field output stage power supply circuits, the steady voltage of Switching Power Supply master is fallen to automatically should the value of need.When transferring operate as normal to, by software or monostable impulse circuit, still continue earlier to keep and turn-off the CRT beam electronic current for a moment, make the main steady magnitude of voltage in original drop back slow gradually liter of being expert at behind the scanning work recover operate as normal and should need after the voltage stabilizing value for a moment, allow after the abundant preheating of picture tube CRT filament, CRT is entered normally should the grating state, reaches energy-conservation and prolongation CRT life-span benefit.

Feature of the present utility model and advantage will be elaborated in conjunction with the accompanying drawings by embodiment.

[description of drawings]

Fig. 1 represents all local figure combination back integrated circuit figure;

Fig. 2 represents the direct sample voltage stabilizing regulating circuit (ASE) of tandem tap power supply of the present utility model;

Fig. 3 represents the direct sample voltage stabilizing regulating circuit (ASE) of series connection pressure swing type Switching Power Supply of the present utility model;

Fig. 4 represents Switching Power Supply master load end, and (+B) voltage, the capable promotion of bootstrapped switch boost type level power supply (5VCPU) and row oscillation power HVCC, row energization pulse Hpp is in operate as normal, standby (DCOFF), suspend (Pe) and switch relevant sequential oscillogram mutually;

Fig. 5 represents kickback transformer FBT characteristic pattern;

Fig. 6 represents the series amplification rheostatic voltage-stabilized power supply circuit figure of multi-functional control, electronic filtering, each output of soft start, low-power consumption;

Fig. 7 or Fig. 8, Fig. 9 represent double bright spot and the CRT filament pre-heating circuit of lengthening the life of cutting of colour TV machine open/close protecting against shock sound;

Figure 10 presentation graphs 7 or Fig. 8, Fig. 9 functional-block diagram;

Figure 11 represents 1 concrete local figure in Figure 10 functional-block diagram;

2 concrete local figure in Figure 12 (or Figure 13, Figure 14) expression Figure 10 functional-block diagram;

Figure 15, Figure 16, Figure 17, Figure 18 represent light lotus root-metal-oxide-semiconductor pincushion correction circuitry;

Figure 19 represents all local figure combination back integrated circuit figure.

φ represents variable or removable end." * " number expression can be debugged change parameter according to reality.During the former elementary conducting of pulse transformer, primary and secondary induction polarity end of the same name is represented with black round spot without exception.Common triode can preferably replace into field effect transistor etc.(particularly element and the item thereof) that specification and accompanying drawing are not explained explained by the legal or current example of passing through.[circuit element and item thereof are not only represented a plurality of local figure element network annexations, and represent the relevant attribute BOM of accompanying drawing item parameter among this schematic diagram mapping nature printing circuit board PCB with element, and not all at this specification and mark, only supply the innovation preferred embodiment specific product with reference to].Select arbitrarily to connect (also can remove) by light as: fingers such as J21 to J29 with single-pole double throw bit switch symbol.In the different accompanying drawings, contain the identical bits labelled notation, have same target, refer to that function or performance effect are identical.Vcc can refer to arbitrary power supply hot end, can be the different electrical power voltage value, and except that Vcc, identical accompanying drawing item tagger can be connected in the same accompanying drawing.Each figure effect sees hereinafter explanation for details.

[embodiment]

In this specification, " trace rectification " refers to that pulse transformer is secondary by the same polarity rectification filtering circuit that serial connection diode rectification loop is with originally the coil on/off is identical." flyback rectification " refers to that pulse transformer is secondary by the reversed polarity rectification filtering circuit that serial connection diode rectification loop is with originally the coil on/off is opposite.

The innovation, complete machine any rectification filtering circuits at different levels all adopt the soft start scheme that the surge overcurrent impacts of opening of cutting down.Can effectively prevent rectifying tube breakdown potential container failure of removal.And double electronic filtering effect, reduce capacitance.

As Fig. 2, shown in 3, the input stage that described steady control regulating circuit is transistor A3 is got and is come from Switching Power Supply or pressure swing type Switching Power Supply, reference level connects power supply+B and ground connection respectively by the divider resistance branch road, surely control in the switching power supply direct sample and to increase the output that is connected on transistor A3 and the soft switch between the ground in the regulating circuit (ASE), be parallel to voltage-reference diode W3 two ends soft start capacitor C32, when making starting up or standby transfer operate as normal to, delaying main steady magnitude of voltage is raised to the operate as normal stable state and should needs the magnitude of voltage time by low voltage value is slow, just can alleviate each output rectification filtering circuit of switching power supply and open the harm of surge impact overcurrent, and offset except that the switching on and shutting down impulsive sound favourable.Described soft switch comprises one group of capacitor C that is in parallel 32 and diode W3, and the negative pole of described diode W3 connects the output of transistor A3, plus earth.Described capacitor C 32 is an electrochemical capacitor, and the negative pole of anodal and described diode W3 is connected, the minus earth of described electrochemical capacitor.Described diode W3 is the voltage stabilizing didoe of a voltage stabilizing didoe or two series connection.

The voltage of electrochemical capacitor C32 can pass through diode D14, direct sample resistance R 2, R10, the repid discharge of R22 branch road during shutdown.

Thereby also comprise and be used for when suspending, making main steady voltage falling to should the value of need making television set enter the interface circuit of halted state.

Voltage-stabiliser tube W3 can be used by one or two voltage-stabiliser tube series aiding connection.Diode D323 branch road can connect on two voltage-stabiliser tube W3 series connection interface points.

Because the small signal system power supply generally all is to power through series amplification rheostatic voltage stabilizer, start the harm of impact overcurrent and reduce power consumption in order to alleviate each output of various series amplification rheostatic voltage stabilizers, adopt Fig. 6 exemplary scenario, respectively at various pressurizer voltage-reference diode W51, W12, W54, W9A two ends soft start control capacitance in parallel C51, C110, C54 not only prolongs the voltage stabilizing output voltage by the slow steady-state value process that is raised to of low value, and double electronic filter effect, alleviate back level filter capacitor capacity, alleviate voltage stabilizing and adjust the harm of tube loop unlatching surge impact overcurrent.In order to reduce the series amplification rheostatic voltage stabilizer power consumption, just must reducing each series connection amplifies to adjust to manage to collect and penetrates main branch voltage and fall, series connection amplify to be adjusted the pipe collector loop and is got and come from the low voltage power supply source as capacitor C 4, C22, C21, and double above higher voltage power supply is adopted in the base bias loop, as capacitor C 62, and C64 etc.Crosstalk in order to alleviate the TV/AV switching, high intercarrier signal system is separated power supply with video decode, controlling high intercarrier signal system power supply (5V-4) on/off by control valve V54, it is good that power supply can adopt field effect transistor for micro controller CPU or row oscillation power adjustment pipe A5-1, VH, AH.Tandem tap power supply colour TV, line oscillation of power supply source only can be got and come from switch power supply secondary, can not be with the secondary implication of kickback transformer.To come from the secondary power supply of kickback transformer be main and other small-signals are got as far as possible.Powerful audio power amplifier and field output stage are got and come from switch power supply secondary is good.(among Fig. 6, can connect by diode D59 branch road and exchange complete closedown relay tube collector electrode VKC.Realize overvoltage shutdown ACOFF by voltage-stabiliser tube W4 branch road.When exchanging the complete closedown device action, must turn-off micro controller CPU power supply) by diode UP branch road.

In order to realize that the user both can be easy to use energy-conservation, need not frequent standby again as far as possible, thereby also comprising being used for making, the utility model leads steady voltage falling to should the value of need making television set enter the interface circuit of halted state when suspending.As shown in Figure 2, when diode W3 was a voltage-stabiliser tube, the negative pole of voltage-stabiliser tube W323 was connected the negative pole of voltage-stabiliser tube W3, the anodal photoelectric coupled circuit that connects.As shown in Figure 3, when diode W3 was the voltage-stabiliser tube of two series connection, the negative pole of voltage-stabiliser tube W323 was connected series connection place of two voltage-stabiliser tube W3.Pause function has can listen television acoustics separately, and the soft start horizontal output stage of holding concurrently power supply prolongs picture tube benefit in useful life.With usual standby, " screen protection ", " listen " the function difference separately: standby in the past all will at first be cut off line scanning, when the utility model suspends, line scanning is still in work, should the value of need but must the steady magnitude of voltage of control switching master fall to automatically, guarantee that horizontal output stage superhigh pressure is that 0 blank screen state ratio drops on the contrary when image is arranged and is the low voltage phenomenon at the picture tube line, alleviates the superhigh pressure moisture absorption and causes the high voltage arc fault.When entering the innovation pause function, sequential is: after screen apparent " no signal or pressure blank screen economize on electricity noise elimination " character shows earlier, force blank screen indicator light HL3 bright again, turn-off Video Decoder, video amplifier circuit and field output stage circuit, the steady voltage of Switching Power Supply master is fallen to automatically should the value of need.When transferring operate as normal to, by software or monostable impulse circuit [Fig. 7 or Fig. 8, Figure 12, Figure 13 example], still continue earlier to keep and turn-off the CRT beam electronic current for a moment, make the main steady magnitude of voltage in original drop back slow gradually liter of being expert at behind the scanning work recover operate as normal and should need after the voltage stabilizing value for a moment, allow after the abundant preheating of picture tube CRT filament, CRT is entered normally should the grating state, reaches energy-conservation and prolongation CRT life-span benefit.Physical circuit is referring to (by Fig. 7, Fig. 2 or Fig. 3 are after Fig. 6 combination) Fig. 1 example or referring to Figure 19 example.(can turn-off field-scanning circuit by diode Dpe branch road Jdv among this figure.Resistance R 84 branch roads can be connected in series voltage-stabiliser tube).

Figure 19 example: contain [Fig. 2] and suspend the main steady magnitude of voltage circuit of control, quiet double spot suppressor of [Fig. 7 or Fig. 8] ON/OFF and the picture tube filament pre-heating circuit of lengthening the life, [Figure 15, Figure 16, Figure 17, Figure 18] optocoupler-metal-oxide-semiconductor pincushion correction circuitry constitutional diagram.(it is as follows to explain in detail):

Employing contains the colour TV of tandem tap power supply, more helps total shutdown and enters grating contraction state gradually.[Fig. 2 example]: compare in the regulating circuit the steady magnitude of voltage of master when increasing in the operate as normal direct sample by triode Ape and optocoupler N3 control operate as normal.Triode Ape and optocoupler N3 are inoperative during operate as normal, keep normal main steady voltage output.Standby or when suspending, or the row oscillation power maintains halted state when not building up without exception, makes main steady voltage falling lower voltage value or holding state.Fig. 2 circuit optocoupler N3 and triode Ape can save, by optocoupler-metal-oxide-semiconductor pincushion correction circuitry compatibility, referring to Figure 19 example.[Fig. 3 example] is fit to pressure swing type Switching Power Supply occasion, during time-out, by the conducting of D323 branch road, makes main steady voltage falling the value of need enter halted state, and diode D323 negative terminal can connect [Fig. 1 or Figure 19 example] triode Vpe collector electrode or capacitor C 9 positive poles.By the conducting of voltage-stabiliser tube W8 branch road, enter holding state during standby.

Figure 19 example is adapted at specifically utilization in the cold start system with serial switching power supply for colour TV set most; because tandem tap power supply master output belongs to input loop some; must be in electrical network and involve the hot movement that Danger Electric shock risk is arranged; can omit Fig. 2 exemplary circuit; direct sample terminal voltage value when but dual-purpose is directly regulated operate as normal by the optocoupler pincushion correction circuitry; no signal automatic pause or have signal to force the blank screen noise elimination; micro controller CPU output pause instruction Pe high potential; make control valve Vpe conducting; FBT level of source kickback transformer got in shutoff; behind series amplification rheostatic voltage stabilizer adjustment pipe A9-1; capacitor C 9 voltage fallings; make the amplifier tube A72 conducting and the chain conducting of inverter A83 thereof of original shutoff, by diode D85; D86; D87 shutoff video amplifier circuit and CRT three rifles are in blank screen is not had the line state.When previewing is put after grade capacitor C 9 put electricity, then the optocoupler pincushion correction circuitry is by optocoupler N2 input no current, make former the getting of optocoupler N2 output feeder ear Cam come from tandem tap power supply master output capacitor C, after vacation connects load resistance R321 and R322 dividing potential drop, forming power supply (capacitor C 18) voltage raises gradually, when capacitor C 18 magnitude of voltage rising certain values, can puncture the voltage-stabiliser tube W32 branch road that normality is turn-offed, meet load divider resistance R321 and R322 by vacation, pressure-gradient control valve falls to main steady magnitude of voltage and should need to suspend voltage for the steady control circuit of former direct sample.When transferring operate as normal to after time-out or the standby, because pipe A9-1 base stage access soft start capacitor C9A capacity is adjusted in series connection and charge constant is very big.After making voltage stabilizing, capacitor C 9 rises slowly after diode D9 rectification.Preposition triode A72 and rearmounted triode A83 constitute special-shaped multiple tube, constitute the positive feedback role of network by increasing capacitor C 76 resistance R 76 timing elements between preposition triode A72 base stage and the back utmost point triode A83 base stage (or collector electrode), make triode A83, A72 have monostable impulse circuit character, as picture tube filament preheating circuit (2).Starting up or time-out or holding state are forced to be the blank screen state by three diode D85, D86, D87 shutoff picture tube R, G, B three rifle beam electronic currents before just having transferred operate as normal to without exception; after making the abundant preheating of picture tube filament normal; could remove above-mentioned monostable impulse circuit and turn-off the picture tube function; make picture tube enter the grating normal operating conditions, voltage-stabiliser tube WP has overvoltage white peak inhibitory action.

Because the innovation combined switch power supply is unusual, adopts dual steady control loop, can stops arbitrary element interruption or generation overvoltage out of control and export chain big damage phenomenon.Coupling or magnetic coupling intermediary advantage because the innovation work and standby commutation circuit need not to add lustre to after line scanning quits work, just can make Switching Power Supply enter control voltage stabilizing state between preferential standby.So, set up monostable standby mode more.In order to make standby moment, line scanning continuous firing moment enters grating contraction state gradually, during standby, turn-off row vibration series amplification rheostatic voltage stabilizer by control valve VH1, enter the saturation conduction state by the chain pillow school optocoupler N2 that makes of diode VH12 again simultaneously, make capacitor C 18 current potentials fall to diode D323 fast and transfer conducting to, make the of short duration drop gradually of main steady voltage, till row oscillation power CHV and previewing discharge source C9 drop end pillow school optocoupler N2 by the anti-Pianguan County of normality is disconnected.Diode VPe2 can remove.

Because the utility model increases pause function is arranged, can make halted state the horizontal output stage voltage supplied (+B) drop is lower, when transferring operate as normal to by standby or starting up, the line scanning prime preferentially enters normally should need on off state.Because kickback transformer FBT secondary capacitance C21 and the chain previewing discharge source of soft start capacitor C9A C9, reason standby 0 magnitude of voltage rising steady state voltage value is slow, elongates optocoupler N2 cut-off state and is controlling continuous the holding the time of leading steady magnitude of voltage low voltage process.That is, after the line scanning prime operate as normal, and in during the CRT filament pre-heating, make main steady horizontal output stage (H.OUT) voltage supplied just arrive the operate as normal steady-state value for a long time by slow liter of low value.[relevant starting up, work/standby (DCON/OFF), suspend (Pe), capable the promotions level of row oscillator stage power supply source H.VCC and bootstrapped switch boost type power supply source 5V (CPU), row energization pulse Hpp exports and line output H.OUT feeder ear (+B) timing waveform is referring to Fig. 4 example].As seen, when standby transfers operate as normal to, by way of suspending the main steady voltage build-up rate process of (Pe) function control.The innovation pause function soft start horizontal output stage voltage supplied function of holding concurrently is very superior, thus chain raising complete machine and picture tube reliability.Also help and slow down machine open/close moment electromagnetic induction and high potential assembly (particularly electrostatic induction) harm.The innovation no signal automatic pause is about half of existing colour TV " screen protection " or quiescent dissipation owing to turn-off decoded field scanning and sound accompaniment function etc., and energy-saving effect is remarkable.

In order to realize cold start system with serial switching power supply for colour TV set, adopt the optocoupler metal-oxide-semiconductor pincushion correction circuitry [Figure 18 or Figure 19 example] of the innovation, pillow school front end circuit output parabolic shape EW is by amplifier tube, and (or removing optocoupler N2) is connected in control correction tube AM eventually behind optocoupler N2 again.The pillow whole keyholed back plate AM drain D in school (or collector electrode) can take over how to rest the head on school Terminal Capacitance hot end, and the pillow whole keyholed back plate AM source S in school (or emitter) can take over how to rest the head on school electric capacity cold end.What (series connection) Switching Power Supply master output capacitor C optocoupler N2 output feeder ear Cam can take on resistance R 321, R322 dividing potential drop node among this figure.Apply to remove optocoupler N2 under the pressure swing type Switching Power Supply occasion, directly can connect pillow pipe AM input G eventually by resistance R 5G by amplifier tube Ap or An collector electrode (or removing amplifier tube).The innovation is succinctly reliable, serves many purposes, the stable row of cold and hot isolation intermediary and fast temperature compensation width of cloth effect.Wherein, optocoupler N2 magnifying state is exclusively used in the pillow school isolates, and the special-purpose pause function of optocoupler N2 cut-off state is regulated main steady magnitude of voltage drop should the value of need.The special-purpose standby moment line scanning continuous firing just of optocoupler saturation conduction state moment makes the of short duration drop gradually of main steady voltage a moment, enters grating contraction state gradually.

In order to eliminate prior art machine open/close bright-spot eliminating, squelch circuit shortcoming, provide CRT filament pre-heating life-prolonging function.[Figure 10 example]: two groups of voltage sources of voltage difference are arranged in series amplification rheostatic voltage stabilizer (AVR) input in and output out or the source of getting, set up respectively and can make after the outage picture tube CRT enter grating to make picture tube CRT enter cut-off state circuit (2) after the circuit of contraction state (1) and outage or line scanning start or suspend gradually.Setting up is by looking the monostable picture tube CRT filament preheating circuit of putting 2, referring to Figure 12 or Figure 13 example.Enter during the outage of the picture tube set up white raster gradually the circuit of contraction state (1) referring to Figure 11.Can make picture tube CRT enter the grating circuit of contraction state (1) gradually after the outage of setting up, can be by compatible switch machine impulsive-sound eliminating function behind the diode D88 branch road; And with institute setting up after looking monostable pulsed picture tube filament preheating circuit (2) combination of putting, compatible again formation picture tube switching on and shutting down spot suppressor.The concrete feature of the innovation is: select for use to get to come from kickback transformer FBT or the secondary arbitrary output of switching mode power supply transformer, behind series amplification rheostatic voltage stabilizer AVR, (can power to look put preposition etc.), at this series amplification rheostatic voltage stabilizer AVR input in (capacitor C 21), after diode D81 branch road commutation capacitor C81 filtering, as PNP triode A81 outage back power supply source, at this series amplification rheostatic voltage stabilizer AVR output out (capacitor C 9), after diode D71 branch road commutation capacitor C71 filtering, as amplifier tube A72 outage back power supply source.Two triode A81 and A72 all instead end partially during operate as normal.When general supply outage or standby, after at first making triode A81 conducting, make picture tube CRT three rifle RGB conductings enter white raster contraction state gradually by diode D82 parallel with one another, D83, D84 respectively, can force noise reduction MU (eliminating the switching on and shutting down impulsive sound) by (or removal) diode D88 branch road simultaneously.[triode A81 collector load resistor R84 branch road can (increase or remove) serial connection voltage-stabiliser tube].Can (or removal) width of cloth V.AGC be increased with field output stage power supply reduction by diode D89 branch road.At this moment, require line scanning prime power supply appearance capacity very big.[even can guarantee the half that drops after shutdown of main load terminal voltage or the standby, still can produce the output of row energization signal by normal power supply, keep grating and can enter contraction state gradually].After, when this input end capacitor C21 continuation drop deficiency is kept this pressurizer AVR output voltage stabilizing value, or when entering halted state, make the drop of this pressurizer AVR output (capacitor C 9) voltage follow, make another triode A72 by original anti-partially by transferring the positively biased conducting state to, by inverter A83 collector electrode diode connected in parallel D85, D86, D87 forces to turn-off video amplifier circuit, make three negative electrode RGB of picture tube CRT enter cut-off state, this helps superhigh pressure and not exclusively discharges, to next starting up's line scanning, it is favourable to alleviate the anti-surge impact of superhigh pressure winding silicon particle unlatching rectification overcurrent.Fig. 1 or Fig. 7, Fig. 8 example not only prolong CRT useful life, and remove among the kickback transformer FBT bleeder resistance and bring shortcoming, reduce the cost.Above-mentioned triode A72 and rearmounted triode A83 constitute special-shaped multiple tube, constitute the positive feedback role of network by increasing capacitor C 76 resistance R 76 timing elements between preposition triode A72 base stage and the back utmost point triode A83 base stage (or collector electrode), has monostable pulse character after making triode A83, A72 combination, as picture tube filament preheating circuit (2).(the integrated fast software control of replaceable).Starting up or time-out or holding state are forced to be the blank screen state for a moment by three diode D85, D86, D87 shutoff picture tube RGB three rifle beam electronic currents before just having transferred operate as normal to without exception at every turn; make the main steady magnitude of voltage in original drop back slow gradually liter of being expert at behind the scanning work recover operate as normal and should need after the voltage stabilizing value for a moment; after making the abundant preheating of picture tube filament normal; could remove above-mentioned monostable impulse circuit and turn-off the picture tube function, make picture tube enter the grating normal operating conditions.Reach and prolong CRT life-span benefit.The utility model can be realized by the integrated package internal circuit.According to previewing discharge source voltage height in the integrated package as detection resources, according to scheme of the present utility model, the previewing source is entered just be in the white raster state when standby makes DOFF without exception, when previewing discharge source voltage falling certain value, the automatic blank screen of another rule does not have the line state.Can related parameter be arranged with software adjustment.The innovation overcome the prior art standby start shooting the CRT filament again can not the preheating shortcoming.

The connection base diode V44 negative terminal of triode A81 and series connection place of resistance R 82, the positive pole of diode V44 is got source current C21 positive pole, and making normally has under the grating operating state, and triode A81 penetrates the base knot and is in zero-bias or anti-partially by off state.This biasing resistor R822 other end V.BLK is connected in (through what export behind the inverter) can make the vertical blanking impulse source that makes triode A81 conducting under total outage or the holding state.Described through inverter output back vertical blanking impulse, in the desirable relevant bootstrapped switch boost capacitor of a field output stage circuit cold end and the integrated package internal electron switch junction, field of coming from of this inverter input.As LA7830, LA7841 grade in an imperial examination 7 pin.Therefore, in the time of can reaching total outage or standby along with capacitor C 21 voltage fallings to a certain degree, and during vertical blanking impulse in the time, make triode A81 conducting export that high level is chain to make picture tube three rifle conductings.Can turn-off the horizontal pulse of line scanning pre-driver by triode A81 collector electrode branch road (X) simultaneously this moment.Obtain field flyback and shield the discharge effect that leaks.

After total outage or standby, triode A81 conducting is laggard goes into grating contraction state gradually, [referring to Fig. 6, Fig. 1 or Figure 19 example]: come from switching mode power supply transformer secondary commutation filter circuit capacitor C 4 or C62 behind series amplification rheostatic voltage stabilizer adjuster VH or AH by getting, again by anti-return diode VH9 rectification, behind the large bulk capacitance CHV energy storage, again behind step-down current-limiting resistance RH9, as row oscillation power H.VCC.Because capacitor C HV capacity is big, it is little to load, even drop one half after shutdown of main load terminal voltage or the standby still can produce the output of row energization signal by normal power supply, keeps grating and can enter contraction state gradually, Zong eliminate shutdown or standby speck bad phenomenon.

As follows for the utility model optocoupler-metal-oxide-semiconductor pincushion correction circuitry (how) versatility special explanation: [Figure 18 or Figure 19 example] photoelectrical coupler N2 can choose 4 ends or 6 ends (band feedback exit) portion's product wantonly, can use mutually in same printing board PCB.In Figure 18 or Figure 19 example, by after " 4 " item connects among selection light J21, J22, the J23, specially be used in 4 end optocouplers respectively, connect the back circuit shown in Fig. 15.If select " 6 " item to connect, specially join 6 end optocouplers.According to parabolic shape EW signal source difference, if optocoupler N2 input is respectively by selecting " II " among light J27, J28, the J29 to connect, and and after the elements combination such as NPN triode AN, be applicable to that preposition is " the bottom of a pan " upwards parabolic shape EWII signal [Figure 15 example].If after passing through resistance R e4 branch road and light J29III being connected, can need not preposition amplifier tube AN[Figure 17 example].Optocoupler N2 input is if connect by " I " among light J27, J28, the J29 respectively, and and elements combination such as PNP triode AP after, be applicable to that preposition is " the bottom of a pan " parabolic shape EWI signal [Figure 16 example] downwards.Optocoupler output feeder ear Cam can take over a power supply, and main output capacitor C two ends vacation meets load divider resistance R321 and R322 junction electric capacity c12 is good applicable to tandem tap power supply occasion among this figure.[Figure 15 example] resistance R e6, Re7 and [Figure 16 example] resistance R e3, Re2 mainly regulate the capable width of cloth, the whole keyholed back plate AM of voltage negative feedback resistor R8D in parallel scalable MOS amplification quantity.Therefore, mainly be to regulate pillow school amount.[Figure 15 or Figure 16 example] electric current series connection negative feedback resistor Re8 or Rel cooperate partial pressure type biasing resistor Re6, Re7 or resistance R e3, Re2 to have stabilized current characteristic respectively, the main row width of cloth and the pillow school amount of regulating.The innovation optocoupler pincushion correction circuitry has constant-current driving, dynamic suspension, excellent transmission alternating current-direct current component proportion pass, particularly fast temperature compensation, make start shooting very little to the capable amplitude variationization of steady-state process, pillow school amount and line width adjusting are implicative of each other little, to advantages such as colour TV pipe arrangement and the various parameter variable effects of horizontal output stage are little.Be convenient to produce to simplify debugging, also can make arbitrary colour TV factory set parameter level off to intermediate value.Whole keyholed back plate AM can be field effect transistor or triode.

The Figure of description parameter is only done reference for example, uses former adjustable variable element (" * " number parameter is particularly arranged).For appointing selectable scheme many, the element that need not can be removed or short circuit in the accompanying drawing.The innovation can directly be expanded outer other electron and electrician technical field of utilization TV.

Claims (6)

1. the television power circuit that has soft start, comprise steady control regulating circuit from the switching power supply direct sample, the input stage that described steady control regulating circuit is a transistor (A3) is got and is come from Switching Power Supply or pressure swing type Switching Power Supply, reference level by the divider resistance branch road connect respectively power supply (+B) and ground connection, it is characterized in that: also comprise soft switch in the described steady control regulating circuit, described soft switch series is associated between the output and ground of transistor (A3).

2. power circuit as claimed in claim 1 is characterized in that: described soft switch comprises one group of electric capacity that is in parallel (C32) and diode (W3), and the negative pole of described diode (W3) connects the output of transistor (A3), plus earth.

3. power circuit as claimed in claim 2 is characterized in that: described electric capacity (C32) is electrochemical capacitor, and the negative pole of anodal and described diode (W3) is connected, the minus earth of described electrochemical capacitor.

4. as claim 2 or 3 described power circuits, it is characterized in that: described diode (W3) is a voltage stabilizing didoe.

5. as claim 2 or 3 described power circuits, it is characterized in that: described diode (W3) is the voltage stabilizing didoe of two series connection.

6. power circuit as claimed in claim 1 is characterized in that: thus also comprising being used for making when suspending leads steady voltage falling to should the value of need making television set enter the interface circuit of halted state.

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