CN2257424Y - Telecontrol colour TV protector - Google Patents

Abstract

The utility model relates to a special protector for a telecontrol colour TV, which comprises a power supply circuit, an automatic reset switch circuit, a load current sampling circuit, an over-voltage sampling circuit and a control circuit. The device can automatically cut off an AC power supply after a TV is turned off through telecontrol; when fault phase exceeds voltage, the self AC power supply of the protector is linked to be cut off, automatically locked, etc. Thereby, certain defects of the telecontrol colour TV are compensated. The device has the advantages of simple circuits, and damage prevention. The utility model is suitable for the broad countryside families which have unsteady voltage.

Description

The remote control colour TV set protector

The utility model relates to a kind of electronic protection device, specifically a kind of protector for household electrical appliances.

Commercially available protector for household electrical appliances is usually used in the overvoltage or the instant cut-off protection of refrigerator at present.Include one in the protector for the protector circuit provides the power circuit of direct voltage, one according to mains voltage variations and the control circuit of conducting or turn-off protection device, and several parts such as voltage sample, comparison circuit and delay circuit.Its major function one is when supply voltage surpasses permissible value, and main circuit power is cut off in the protector action; The 2nd, after instant cut-off took place, the work of protector delay circuit recovered to give main circuit power supply behind certain hour, and electrical appliance is resumed work.This protector is after realizing overvoltage protection, and the partial circuit of protector inside burns simultaneously, thereby can not realize the self-protection function of overvoltage.In addition, this protector not too is suitable for the particularity of television set, thereby this class protector seldom is used in the protection of television set usually.

Remote control color tv progressively enters huge numbers of families now, and can not cut off AC power owing to use a teleswitch shutdown, and the situation that causes television set to burn happens occasionally.Under the instant cut-off situation, colour kinescope is also caused certain infringement in addition.Do not sold the protector that remote control colour TV set carries out reliably protecting to these and appeared on the market and have as yet at present.

The purpose of this utility model is a kind of at the above-mentioned defective of remote control colour TV set and the remote-controlled shutdown that designs, the protective device of power failure self-locking with regard to providing, and this protector also can be realized the overvoltage self-insurance simultaneously.

The utility model is achieved in that protective device includes a power circuit that direct voltage is provided for protector, one changes and the control circuit of conducting or turn-off protection device according to mains voltage variations or load current, also include an automatic reset switch circuit, the input of its output connection control circuit is kept conducting state in the certain hour after protector is opened; A load current sample circuit, its output is connected to the automatic reset switch circuit, the variable signal of this circuit output load current; When an overvoltage sample circuit that is connected between power circuit and the control circuit, this circuit surpass fiducial value at supply voltage, send the signal that switches off control circuit.

Below in conjunction with accompanying drawing the utility model is further described.

Fig. 1 is a structured flowchart of the present utility model.

Fig. 2 is a circuit diagram of the present utility model.

In Fig. 1, this protective device is made up of several parts such as power circuit 1, automatic reset switch circuit 2, load current sample circuit 3, overvoltage sampling power supply 4 and control circuits 5, and its particular circuit configurations as shown in Figure 2.Wherein power circuit 1 is from major loop and connects the elementary of transformer B, the secondary rectifier diode D that connects of B ₁, D ₂After meet filter capacitor C again ₁, C ₂, connect three terminal regulator CW (CW then ₇₈₁₂), obtain 12 stable couchers and make voltage.

Automatic reset switch circuit 2 includes triode T ₁, T ₂, T ₁The e utmost point connect the output of power circuit 1, the b utmost point passes through resistance R ₁Connect power supply, through capacitor C ₄Earth connection, the c utmost point is through resistance R ₂Meet T ₂The b utmost point, again through capacitor C ₅Meet T ₂The e utmost point and ground wire.T ₂The c utmost point through resistance R ₃Connect power supply, the c utmost point is exported and connection control circuit 5.In energized moment, 12 volts of voltages are through R ₁Give C ₄Charging is because of C ₄Be equivalent to short circuit at first, T ₁Very low level and conducting of b, give C again ₅Charging.Work as C ₄Charging finishes, T ₁B high level and end C very ₅On fill voltage pass through R ₂Be added to T ₂The b utmost point, make T ₂Saturation conduction, T ₂C utmost point output low level signal, make control circuit 5 conductings.At C ₅Discharge time in (can set about 30 seconds), T ₂Keep conducting.Behind discharge off, T ₂End, c utmost point output high level signal turn-offs control circuit 5.So just realized automatically reseting of this switching circuit, promptly in energized and after not opening the certain hour of television set, protector recovers off state again.

Load current sample circuit 3 is series resistor R in major loop ₈, from R ₈The two ends lead-in wire meets rectifier D ₈With filter C ₇After, connecing the first utmost point of photoelectrical coupler NQ again, NQ secondary is connected to triode T in power circuit output end and the automatic reset switch circuit 2 ₁The c utmost point between.C in automatic reset switch circuit 2 ₅Interdischarge interval is turned on television set, then resistance R ₈On have pressure drop to produce, this voltage becomes the first utmost point that direct voltage is added to NQ after rectification, filtering, make it luminous, inferior utmost point conducting, direct-current working volts are added to T in the switching circuit 2 ₂The b utmost point, make T ₂Keep the saturation conduction state, and then make control circuit 5 keep conducting state, be the television set power supply.If turn-off colour TV with remote controller, then the television set operating current reduces, resistance R ₈On voltage drop drop to deficiency so that the luminous tube on the photoelectrical coupler is luminous, its secondary ending, capacitor C ₅Begin discharge.Through behind the setting-up time, discharge finishes, T ₂End, control circuit 5 is turn-offed, can cut off the power supply of color television set automatically, play a protective role.

Overvoltage sample circuit 4 is by two divider resistance (R ₄, R ₅) branch road constituting forms, and is connected between power circuit 1 and the ground wire input of tapping connection control circuit 5 in the middle of it.Outside supply voltage just often, the dividing potential drop output valve of this circuit be lower than its counter-rotating level, control circuit 5 normallies.When voltage raise above permissible value, this circuit dividing potential drop output valve increased, and made control circuit 5 counter-rotatings, cuts off major loop, thereby colour TV and protector are all played a protective role.

Control circuit 5 is with integrated KA ₅₅₅(IC) be master element, its 2 pin and 6 pin inputs are respectively through diode D ₃Take over and press sample circuit 4, again through diode D ₄Connect the output of automatic reset switch circuit 2.Its 5 pin is connected on resistance R ₆With voltage-stabiliser tube D ₅The centre of branch road, its 3 pin output is connected to triode T ₃The b utmost point, T ₃E utmost point serial connection relay J.The contact J of relay J ₁Be serially connected with on the major loop, reset switch K is connected to J ₁Two ends, on major loop, also be connected to a plug and at least one socket C.Plug is in order to connect external power, and socket uses for colour TV.As seen from Figure 2, meet down reset switch K, power circuit 1 provides 12 volts of direct-current working volts, triode T ₁, T ₂Conducting, T ₂C low level very, 2,6 pin of IC are low level, 3 pin output high level makes T ₃Saturation conduction, relay get electric adhesive, contact J ₁Closure makes the major loop energising.This moment, colour TV was opened, and produced operating current, through 3 samplings of load current sample circuit, made T ₂Continue conducting, the protector stable power-supplying.When 2,6 pin of IC were the high level input, 3 pin were low level, T ₃End, relay J is decontroled, contact J ₁Disconnect main circuit power.

IC at control circuit 5 ₅Pin passes through resistance R ₆With voltage-stabiliser tube D ₅Be its predeterminated voltage, at line voltage just often, the dividing potential drop output valve of overvoltage sample circuit 4 is less than this predeterminated voltage, and IC is nonreversible.When the voltage superelevation, the dividing potential drop output valve increases, after its 5 pin voltages greater than IC, and the IC counter-rotating, 3 pin output low levels, and make T ₃End.

When this protector and colour TV operate as normal, if any instant cut-off, then the relay in the protector can not resume work colour TV moment because of dead electricity disconnects its contact, thereby reaches the purpose of protection picture tube.Have a power failure during to length, also can reach the purpose of power failure self-locking.

The shared same circuit of this device remote control ac dump and overvoltage protection, circuit is simple, reliable operation, not fragile.Model machine is on probation to reach 1 year, and every defencive function all can intactly embody.In the unsettled vast rural households of operating voltage, this device will be brought into play bigger effect.

Claims (5)

1, a kind of remote control colour TV set protector; include a power circuit (1) that direct voltage is provided for protector; one changes according to mains voltage variations or load current and the control circuit (5) of conducting or turn-off protection device is characterized in that this device also has:

An automatic reset switch circuit (2), the input of its output connection control circuit (5) is kept conducting state in the certain hour after protector is opened,

A load current sample circuit (3), its output are connected to automatic reset switch circuit (2), the variable signal of output load current,

An overvoltage sample circuit (4) that is connected between power circuit (1) and the control circuit (5) when supply voltage surpasses fiducial value, sends the signal that switches off control circuit.

2, remote control colour TV set protector according to claim 1 is characterized in that automatic reset switch circuit (2) includes triode T ₁, T ₂, T ₁The e utmost point connect power circuit output end, the b utmost point passes through resistance R ₁Connect power supply, through capacitor C ₄Earth connection, the c utmost point is through resistance R ₂Meet T ₂The b utmost point, again through capacitor C ₅Meet T ₂The e utmost point and ground wire, the c utmost point of T2 is through resistance R ₃Connect power supply.

3, remote control colour TV set protector according to claim 1 is characterized in that load current sample circuit (3) is series resistor R in major loop ₈, from R ₈The two ends lead-in wire meets rectifier D ₈With filter C ₇After, connecing the first utmost point of photoelectrical coupler NQ again, NQ secondary is connected to triode T in power circuit output end and the automatic reset switch circuit (2) ₁The c utmost point between.

4, remote control colour TV set protector according to claim 1 is characterized in that overvoltage sample circuit (4) is by two divider resistance (R ₄, R ₅) branch road constituting forms, and is connected between power circuit (1) and the ground wire input of tapping connection control circuit (5) in the middle of it.

5, remote control colour TV set protector according to claim 1 is characterized in that control circuit (5) is with integrated KA ₅₅₅(IC) be master element, its 2 pin and 6 pin inputs are respectively through diode D ₃Take over and press sample circuit (4), again through diode D ₄Connect the output of automatic reset switch circuit (2), its 5 pin is connected on resistance R ₆With voltage-stabiliser tube D ₅The centre of branch road, its 3 pin output is connected to triode T ₃The b utmost point, T ₃E utmost point serial connection relay J, the contact J of relay J ₁Be serially connected with on the major loop, reset switch K is connected to J ₁Two ends, on major loop, also be connected to a plug and at least one socket C.

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