CN1540979A - Device for demagnetizing clor TV set through automatic switchover and preventing overcurrent impulsion when turning on TV set - Google Patents

Abstract

Single-pole double-throw switch relay is utilized to put auto degaussing loop and current limiting circuit though when reset is executed at time of starting up or power breakdown. After operation, the device sets up shorting current limiting resistor and cuts off degaussing loop. Advantages of the invention are: reducing power consumption at stand by raising reliability etc. ratio between performance.

Description

The double overcurrent percussion mechanism that prevents to start shooting of colour TV automatic switchover demagnetization

Affiliated technical field

The present invention relates generally to TV technology.

Background technology

Prior art, colour TV is if stand-by power consumption less than 3W, adopts standby power and main power source to separate scheme, so cost is expensive before.The now normal operate as normal switching power supply standby power function scheme of holding concurrently that adopts can reduce cost.The standby power function but prior art colour TV Switching Power Supply is held concurrently, the complete machine stand-by power consumption is bigger, generally greater than 5W.Causing the big reason of colour TV complete machine stand-by power consumption is that colour TV all has automatic degaussing circuit.Wherein, though three end field-discharge resistances are better than two end field-discharge resistance erasure effects.But when electrical network was higher than 230V, this resistance power consumption was just much larger than 2W.Other any circuit power consumption can be also little under holding state.So colour TV will be set up the automatic switchover degaussing circuit or directly reduce field-discharge resistance element oneself power consumption is to reduce colour TV holding state power consumption basis.But research and development reduce the field-discharge resistance power consumption, can not compatibility satisfy best erasure effect again.Besides prior art automatic degaussing circuit, usually simple serial connection semistor, the long-term energising of this thermistor works under the high voltage state, the normality energising has power consumption, fragile, there is interference in the demagnetization loop to other circuit, so some manufacturer is connected in series a single-pole single-throw(SPST bit switch relay again in original autodegauss loop, connect the autodegauss loop after reaching the starting up, after finishing, demagnetization cuts off the autodegauss loop again, contact required very high when this scheme required the actuating of relay, the maximum electric current of make-and-break ability of switching should reach 20A, and this pulling relay coil is in cold movement, and switch contact is in hot movement, requires very high to dielectric voltage withstand.So this single-pole single-throw(SPST position relay cost is expensive.Large-screen color TV all has been connected in series fixed resistance value high-power resistance or negative tempperature coefficient thermistor from the direct current rectifying and wave filtering circuit of electrical network, the surge impact electric current is to rectifier or filter harm when alleviating the starting up, this current-limiting resistance electric current produces voltage drop after the operate as normal has interference to other circuit, and the heating effect of current power consumption is very big, some manufacturers adopts single-pole single-throw(SPST bit switch relay to make this current-limiting resistance of short circuit in parallel after the operate as normal, have energy-conservation noiseless advantage, but also increased cost.At prior art performance and price ratio shortcoming.

Summary of the invention

The innovation purpose is only used a single-pole double throw bit switch relay and interlock circuit thereof, has or has exceeded the above-mentioned best beneficial effect of single single-pole single-throw(SPST bit switch relay that adopts separately, has improved the ratio of performance to price.Outstanding advantage: 1, reduce stand-by power consumption; 2, reduce the field-discharge resistance failure rate; 3, the overcurrent that prevents to start shooting impacts the electrical network rectifier filter is endangered.

Realize that the indispensable scheme of the innovation is: increase that this single-pole double throw bit switch of single-pole double throw bit switch relay K B is not switched on or reset without exception during the starting up and be one group (O-P1) and connect the autodegauss loop, another group (O-P2) contact disconnects bypass in parallel at current-limiting resistance R20 two ends, allow current-limiting resistance R20 bring into play the current limliting function, after startup finishes, relay coil produces the magnetic force adhesive by electric current, make hilted broadsword O set P2 short circuit current-limiting resistance R20, make it to lose metering function; Cut off the autodegauss loop simultaneously.Reach energy-conservation beneficial effect.With the relay interlock circuit, adjunction positive feedback network has pulsed and switches advantage fast.Slow down relay tube conducting/turn off process, the approach amplification region time.

The innovation advantage has been brought into play the dual-purpose performance that element should be use up, and enhances product performance/the price ratio.Because the innovation is with technology is opposite habitually in the past, single-pole single-throw(SPST bit switch relay always cuts off the power supply or starting up's access failure autodegauss loop just of short duration connection cold conditions demagnetization loop after the startup habitually in the past, so the switch current rate of change is very big between the actuating of relay, there is the arcing of overcoming phenomenon must increase cost.And this pulling relay coil is in cold movement, and switch contact is in hot movement, requires very high to dielectric voltage withstand.And the innovation, connected and the demagnetization function that finished before the action of relay coil energising adhesive contact, under the hot high resistant demagnetization circuit environment, make actuating of relay switch current rate of change very little, so to relay in requisition for when action the contact switching capability require lowlyer, can reduce cost or improve reliability.Prior art relay interlock circuit is complicated in addition, element is many, and this is opposite with the innovation.No matter prior art is that separately independent increase standby power or increase demagnetization relay cost must be higher than more than 3 yuan.And the innovation: select single-pole double throw position beginning relay for use, after demagnetization finishes, just double-throw contact.So the actual switch current ability that should need of circuit is less than 1A, and the just double-throw contact when demagnetization of factories such as Sony, Skyworth, so circuit should need about switch current ability 20A, Skyworth adopts switch current 10A single-pole single-throw(SPST position relay, 0.55 watt of relay coil power consumption.Even and the innovation is adopted switch current 12A single-pole double throw position relay, the relay coil power consumption is less than 0.36W/12V (0.24W/9V) watt, though be not suitable for cold and hot isolation occasion, so place hot base plate, but price is low, about about 1.45 yuan or lower,, than 3.6 yuan low of manufacturer's original products such as Skyworth more than 2 yuan.And work back bypass short circuit current-limiting resistance, current-limiting resistance is the bigger the better when helping solving the starting up, the smaller the better advantage best of breed of current-limiting resistance contradiction during operate as normal.The innovation advantage: reduce electrical network rectifier filter and field-discharge resistance spoilage, and formation makes the basis of stand-by power consumption less than the least cost preferred plan of 3W.Simultaneously, also directly fall cost and lay the first stone for reducing the degaussing coil astragal from now on.

Description of drawings

Figure of description has 3 page of 4 width of cloth.Fig. 1 or Fig. 2 example single-pole double throw bit switch relay and interlock circuit thereof specifically use.Fig. 3, Fig. 4 example be specifically utilization in TV.(particularly element and the item thereof) that specification or accompanying drawing are not explained explained by the legal or current example of passing through.φ represents variable or removable end.Common triode is optional with field effect transistor replacement etc.In the different accompanying drawings, contain same tag, 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

Describe realization the innovation best way in detail below in conjunction with accompanying drawing, preamble has just illustrated and has no longer repeated.Be connected in series the pure self-induction choking coil L1 and the L2 of nothing (power frequency) mutual inductance respectively at colour TV electrical network inlet wire, both can replace current-limiting resistance R20 to reduce start and impact overcurrent harm, can suppress symmetric disturbance and asymmetric interference and Harmonic Interference effect again along the power line transmitted in both directions, impact overcurrent harm in order to slow down start, improve colour TV from direct commutation capacitor filtering of electrical network and normality field-discharge resistance reliability, increase energy-efficient performance.For this reason: the innovation increases single-pole double throw bit switch relay K B and relevant circuit thereof.(Fig. 1 example), electrical network inlet wire current-limiting resistance and field-discharge resistance are used to automatically switch.Increasing electrical network inlet wire current-limiting resistance R20 resistance when complete machine outage or starting up is that 20 Europe are above for good; At this moment, single-pole double throw bit switch relay K B coil blackout automatically resets hilted broadsword O to be (O-P1) to connect the demagnetization loop; After demagnetization and starting up finished, relay K B coil electricity produced the magnetic force adhesive and makes hilted broadsword O set be the O-P2 end to be connected short circuit electrical network inlet wire current-limiting resistance R20 in parallel.Make it to have lost metering function, be no-resistance state, cut off loop after the demagnetization that finishes simultaneously.Therefore the innovation has the energy-conservation and reliability advantage of increasing.Current-limiting resistance R20 can select the negative tempperature coefficient thermistor replacement for use in the accompanying drawing.Amplifier tube V5 and relay tube VKB and interlock circuit equivalence thyristor function thereof.Therefore, relay tube VKB can be replaced by thyristor.The accompanying drawing example, relay tube VKB and preposition pipe V5 form special-shaped multiple tube, constitute self-locking positive feedback network by resistance R 7 branch roads, have pulsed and switch advantage fast.Slow down in relay tube VKB conducting/shutoff handoff procedure the approach amplification region time.Can replace and surmount the thyristor functional advantage.(and have carrying load ability strong, the little low cost and other advantages of conduction voltage drop).The innovation, relay K B and interlock circuit thereof can be placed the hot base plate that involves with AC network entirely.Resistance R 46 and capacitor C 46 etc. have anti-interference function, resistance R 7 is positive feedback branch, desirable 12V or the 15V left and right sides power supply of coming from of accompanying drawing relay K B and interlock circuit thereof, in the relay circuit opening process, adopt pulse mode, after resistance R 619 and the 618 differential moment impact overcurrent conductings of acceleration switch capacitor C, the suction-combining force during the firm conducting of reinforcing relay coil has just advanced to fall voltage threshold currents electricity-saving state after relay K B main contact is connected fast.After the relay coil conducting, below its both end voltage drop 9V.The innovation constitutes makes the basis of stand-by power consumption less than the least cost preferred plan of 3W.Simultaneously, also lay the first stone for reducing degaussing coil astragal footpath cost from now on and reducing electrical network rectifier filter cost.

Example parameter only illustrates as most preferred embodiment in this specification or the accompanying drawing, but produces the former modulation of utilization.For appointing selectable scheme many, the element that need not can be removed or short circuit in the accompanying drawing.The innovation such scheme can be expanded utilization single-pole double throw bit switch relay, makes the hilted broadsword connection standby power that resets, and switching power supply is connected in work back set, cuts off standby power.

The innovation can be expanded outer other field utilization of TV technology.

Claims (5)

1. one kind contains the color television set that electrical network inlet wire current-limiting resistance, degaussing circuit and relay and interlock circuit thereof are formed, and it is characterized in that:

Relay (KB) contains the single-pole double throw bit switch, and when complete machine outage or starting up, relay (KB) hilted broadsword (O) connections (O-P1) contact that resets without exception allows current-limiting resistance (R20) only can bring into play metering function when starting; After starting up and demagnetization finished, the relay coil galvanization produces the magnetic force adhesive made hilted broadsword (O) set connect (O-P2) end, and short circuit current-limiting resistance (R20) makes it to lose metering function, cut off loop after the demagnetization that finishes simultaneously.

2. according to right 1 described colour TV, it is characterized in that: relay (KB) and the circuit that involves mutually thereof can be placed the hot base plate that involves with AC network entirely.

3. according to right 1 described colour TV, it is characterized in that: relay tube (VKB) and preposition pipe (V5) are formed special-shaped multiple tube, constitute self-locking positive feedback network by resistance (R7) branch road, have pulsed and switch advantage fast, slow down in relay tube (VKB) conducting/shutoff handoff procedure, the approach amplification region time, can replace and surmount the thyristor function.

4. according to right 1 described colour TV, it is characterized in that: in the relay circuit opening process, adopt pulse mode, after resistance (R619) and the conducting of acceleration switch electric capacity (C618) differential moment impact overcurrent, the suction-combining force during the firm conducting of reinforcing relay coil has just advanced to fall voltage threshold currents electricity-saving state after relay (KB) main contact is connected fast.

5. according to right 1 described colour TV, it is characterized in that: on the AC network inlet wire, be connected in series pure self-inductor L1, the L2 that does not have (power frequency) mutual inductance respectively, the symmetric disturbance along the power line transmitted in both directions, asymmetric interference and Harmonic Interference both can have been cut down, again replaceable current-limiting resistance function.

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