CN2072737U - Multi-functional safety device for electric equipments - Google Patents

Abstract

The utility model relates to a multi-functional safety device for electric equipment, which is an improvement of the existing multi-functional safety device. The utility model is characterized in that a unique trigger circuit of a silicon controlling rectifier is designed, a voltage sensitive resistor and a fixed resistor are used to connect in series with a voltage division return circuit to provide an over voltage trigger signal, a proper delaying circuit is designed in the over current trigger circuit, and the multi-functional safety device can recognize the surge current when domestic appliances are switched on to prevent misoperation. The utility model has the advantages of simple structure, high safety and low cost, and the performance index meets the requirement of the national standard GB6829-86.

Description

Multi-functional safety device for electric equipments

The utility model belongs to the electrical equipment protective device, is the improvement to present multifunctional circuit-protecting device.

The electrical equipment protector that a lot of forms are arranged at present, for example Chinese patent application CN88201247U is a kind of of wherein better performances.The form that opens circuit that it adopts miniature relay to combine with rapid fuse.Its major defect is: 1. the rapid fuse price is expensive, and must upgrade after the fusing, make troubles to use, and the user easily makes a mistake when changing, and should not promote the use of in the family.2. overvoltage protective property is poor.3. when producing bigger start surge current, household electrical appliance easily produce misoperation.This also is the common drawback of current other various electrical equipment protectors.Actual measurement shows, for example than the color television set of large-screen, the erasing current peak-to-peak value can reach 30A～40A even bigger to some household electrical appliance during its start, and the overcurrent index of protector is generally set up at 10A～20A, this just easily makes protector produce misoperation, hinders the normal use of household electrical appliance.

The purpose of this utility model provides a kind of electric leakage, overvoltage, overcurrent, the perfect novel electrical equipment protector of short-circuit protection function; its overvoltage protection is highly sensitive; can discern the surge current of household electrical appliance start; prevent misoperation; and simple in structure, cheap, be suitable for promoting the use of in the family.

Technical solution of the present utility model is, in a housing that has a power supply input and output terminal electro-magnetic circuit breaker TQ is installed, and the hand-reset double-pole normally closed switch ZK on it is connected between the power supply input and output terminal rectifier bridge D _5～8Be connected on ZK after TQ connects and connect a side to the lead-out terminal of power supply, D _5～8The direct voltage of output provides bias voltage for earth leakage protective controllable silicon SCR 1 and overvoltage, overcurrent, short-circuit protection controllable silicon SCR 2, electric leakage instrument transformer B ₁, electric leakage circuits for triggering and SCR1 form leakage protection circuit, the leak(age) test loop can provide the simulation leakage current, the noncontacting switch of connecting when controllable silicon SCR 2 is overvoltage, overcurrent, short circuit, instrument transformer B ₂Sampled signal when overcurrent, short circuit are provided, essential characteristic of the present utility model is to provide to SCR2 the circuit structure of triggering signal:

1. the overvoltage circuits for triggering are by capacitor C ₂, isolation resistance R ₃With a piezo-resistance R _U2With fixed resistance R ₄The series connection dividing potential drop loop that constitutes is formed, R _U2An end and D _5～8Positive output end connect R ₃One termination R _U2With R ₄Tie point, the trigger electrode of the other end and SCR2 and C ₂Positive pole connect;

2. the short circuit circuits for triggering are by capacitor C ₃, R ₅With R ₆The electric resistance partial pressure loop and the diode D that constitute ₁₀Form C ₃With B ₂Secondary coil and R ₅, R ₆Divide the hydraulic circuit parallel connection, D ₁₀Positive pole meet R ₅With R ₆Tie point, negative pole is connected with the trigger electrode of SCR2;

3. by diode D ₉, D ₁₁, capacitor C ₄, C ₅, resistance R ₇, R ₈, R ₉The overcurrent circuits for triggering of the surge current when composition can be discerned the household electrical appliance start, C ₄With R ₇, R ₈The branch hydraulic circuit parallel connection that constitutes, D ₉Positive pole meet R ₅With C ₃Tie point, negative pole meets R ₇With C ₁Tie point, D ₁₁With C ₅Constitute series loop, D ₁₁Positive pole and C ₅The anodal connection, negative pole is connected with the trigger electrode of SCR2, isolation resistance R ₉One termination R ₇With R ₈Tie point, another termination D ₁₁With C ₅Tie point.

Above-mentioned three circuits for triggering form or logic triggers the SCR2 conducting when overvoltage, overcurrent or short circuit take place.By D _1～4, C ₁And R ₂The electric leakage circuits for triggering of forming when getting an electric shock (or the person) when electric leakage takes place trigger the SCR1 conducting, and SCR1 and SCR2 form or logic one of can be therein drives the TQ action during conducting and opens normally-closed contact ZK and cut off the electricity supply.The utility model has promptly been realized electric leakage, overvoltage, overcurrent, short circuit kinds of protect function like this.

Major advantage of the present utility model is:

The first, defencive function is perfect.Can leak electricity, cut off the electricity supply reliably under the electric shock, overvoltage, overcurrent, the various situations of short circuit.

The second, the performance index of electric leakage, electrical shock protection reach the GB requirement.

The 3rd, because the time-lag action of the circuits for triggering of appropriate design in the overcurrent protection makes the utility model can discern the surge current of household electrical appliance, prevent misoperation, guarantee the normal use of household electrical appliance.

The 4th, circuit structure is simple, and is with low cost, is convenient to promote the use of.

Accompanying drawing is an electrical schematic diagram of the present utility model.

Be described in detail operation principle of the present utility model, circuit parameter, using method and performance index below in conjunction with accompanying drawing.Referring to Fig. 1,1,2 is power input terminal, leakage current transformer 5(B ₁) elementary two coils be connected in series respectively in live wire and the zero line.The 6th, have the circuit breaker of double-pole normally-closed contact, its solenoid TQ and rectifier bridge D _5～8Connect power supply after the series connection.B ₁Secondary coil connect the electric leakage circuits for triggering 10, constitute leakage protection circuit with SCR1.This part is identical with existing earth leakage protective device, does not repeat them here.The leak(age) test loop is by push-button switch Y _AAnd R ₁Constitute, be connected between the power output terminal 3,4, the simulation leakage current can be provided.By piezo-resistance R _U1The anti-lightning strike loop 9 that constitutes is connected on power output end, the high frequency voltage that may respond to during the bypass thunderbolt, and the protection electrical appliance is without prejudice.Current transformer 8(B ₂) sampled signal when overcurrent, short circuit are provided.Its structure is to be iron core with the annular silicon steel sheet, and is elementary around 1～2 circle, is serially connected between ZK and the power output terminal, and secondary 150～300 circles link to each other with the circuits for triggering input of SCR2.SCR2 is connected in parallel on rectifier bridge D as load _5～8Output when the SCR2 conducting, makes the electric current that flows through TQ increase to certain numerical value and moves, and normally closed interlock ZK is opened and cuts off the electricity supply.The 11st, overvoltage circuits for triggering, piezo-resistance R _U2Choose the MY type, the puncture voltage of its electric current 1 MAH is between 300V～470V the time, resistance R ₄The apolegamy scope be 200 Ω～36K Ω, this is because R _U2Parameter discrete in the mill causes.Can replace R with adjustable resistance or potentiometer ₄So that adjust.R ₃Be isolation resistance, its value is 10K Ω～150K Ω, adjusts R ₃Can change trigger current and satisfy the requirement that triggers SCR2, simultaneously R ₃, R ₄Constitute C again ₂Discharge loop.When overvoltage surpasses setting, R _U2Puncture SCR2 conducting, TQ action power dump.

The 13rd, the short circuit circuits for triggering.R ₅With R ₆Dividing total resistance of hydraulic circuit is 10K Ω～20K Ω, voltage ratio R ₆: R ₅=1:1～1:5, C ₃Be 1～10 μ f.C ₃But bypass High-frequency Interference clutter.When operate as normal, B ₂The signal of output is very little, D ₁₀Not conducting; When short trouble appears in electrical appliance, D ₁₀Providing the positive polarity trigger impulse rapidly cuts off the electricity supply the SCR2 conducting.

The 12nd, the overcurrent circuits for triggering.C ₄Be filter capacitor, with D ₉The pulsating direct current mean value that provides is brought up to

Doubly, isolation resistance R ₉From R ₇, R ₈Dividing point obtain direct voltage, R simultaneously ₇, R ₉With C ₅Forming the RC delay circuit makes trigger impulse trigger SCR2 again after predetermined time-delay, select the parameter of Resistor-Capacitor Unit can make this circuit have the effect of identification surge current rightly, it only could trigger SCR2 when power supply main circuit current effective value meets or exceeds rated value, misoperation does not take place the surge current when household electrical appliance are started shooting.D ₁₁Be isolating diode, make 11 and 13 not disturb mutually.R ₇Numerical value be 0～75K Ω, R ₈Be 75K Ω～100K Ω, R ₉Be 0 Ω～43K Ω, C ₅Be 47 μ f～100 μ f.

According to principle shown in Figure 1, the device parameter values of an embodiment of the present utility model is: R _U2: MY2/V _1mA330V, R _U1: MY2/V _1mA560V, R ₄: (200 Ω～36K Ω), R are determined in the debugging of RT-0.125 resistance ₃: RT-0.125-150K Ω, R ₅: RT-0.125-10K, R ₆: RT-0.125-2K, C ₃: 4.7 μ f/25V, R ₇: RT-0.125-8.2K Ω, R ₈: RT-0.125-100K Ω, R ₉: (0～43K Ω), C are determined in debugging ₅: 47 μ f/10V.SCR1 and SCR2 adopt more than the 1A, and trigger voltage is less than 0.2V, and the controllable silicon of trigger current 5～150 μ A does not have specific (special) requirements to diode.Embodiment of the present utility model satisfies the requirement of GB GB6829-86 through actual measurement check feature index:

1. cut off the electricity supply the time less than 0.1 second when leaking electricity (electric shock).

2. overvoltage protection:

(1) specified 270V ± 5%;

(2) specified 260V ± 4%;

(3) can accomplish arbitrary value within specified 200V～380V by customer requirements.

3. short-circuit protection operate time was less than 0.1 second.

4. overcurrent protection is adjustable is decided to be arbitrary value within 10A～20A, anti-surge time-delay 2～7 seconds.

Using method of the present utility model is, protector is installed between electric power incoming line and the load get final product.If owing to leak electricity, overvoltage, overcurrent or short circuit make the protector action, cut off power supply, should check earlier that the reason that is out of order is also got rid of, and manually makes the ZK closure can recover to power to electrical appliance then.

Claims (5)

1, a kind of multifunctional electric appliance protector, comprise power circuit breaker 6 (TQ), with the rectifier bridge D that connects power supply after TQ connects _5～8, earth leakage protective controllable silicon SCR 1, leakage current transformer 5 (B ₁), electric leakage circuits for triggering 10, leak(age) test loop 7, overvoltage, overcurrent, short-circuit protection controllable silicon SCR 2, overcurrent, short circuit instrument transformer 8 (B ₂), power input terminal 1,2, lead-out terminal 3,4 and housing is characterized in that,

(1), overvoltage circuits for triggering 11 are by capacitor C ₂, isolation resistance R ₃With piezo-resistance R _U2With R ₄The series connection dividing potential drop loop that constitutes is formed, R _U2An end and rectifier bridge D _5～8Positive output end connect R ₃One termination R _U2With R ₄Tie point, the trigger electrode of the other end and SCR2 and C ₂Positive pole connect;

(2), short circuit circuits for triggering 13 are by capacitor C ₃, R ₅With R ₆The electric resistance partial pressure loop and the diode D that constitute ₁₀Form C ₃With B ₂Secondary coil and R ₅, R ₆Divide the hydraulic circuit parallel connection, D ₁₀Positive pole meet R ₅With R ₆Tie point, negative pole is connected with the trigger electrode of SCR2;

(3), by diode D ₉, D ₁₁, capacitor C ₄, C ₅, resistance R ₇, R ₈, R ₉The overcurrent circuits for triggering 12 of the surge current when composition can be discerned the household electrical appliance start, C ₄With R ₇, R ₈The branch hydraulic circuit parallel connection that constitutes, D ₉Positive pole meet R ₅With C ₃Tie point, negative pole meets R ₇With C ₄Tie point, D ₁₁With C ₅Constitute series loop, D ₁₁Positive pole and C ₅The anodal connection, negative pole is connected with the trigger electrode of SCR2, isolation resistance R ₉One termination R ₇With R ₈Tie point, another termination D ₁₁With C ₅Tie point.

2, protector according to claim 1 is characterized in that, in the said overvoltage circuits for triggering 11, as piezo-resistance R _U2Choose the MY type, when the puncture voltage during its 1mA is 300V～470V, R ₄The apolegamy scope be 200 Ω～36K Ω, R ₃Be 10K Ω～150K Ω.

3, according to claim 1 or 2 described protectors, it is characterized in that R in the said short circuit circuits for triggering 13 ₅With R ₆Dividing total resistance of hydraulic circuit is 10K Ω～20K Ω, voltage ratio R ₆: R ₅=1:1～1:5, C ₃Be 1～10 μ f.

4, according to claim 1 or 2 described protectors, it is characterized in that, in the said overcurrent circuits for triggering 12, R ₇Be 0～75K Ω, R ₈Be 75K Ω～100K Ω, R ₉Be 0～43K Ω, C ₅Be 47 μ f～100 μ f.

5, protector according to claim 3 is characterized in that, in the said overcurrent circuits for triggering 12, and R ₇Be 0～75K Ω, R ₈Be 75K Ω～100K Ω, R ₉Be 0～43K Ω, C ₅Be 47 μ f～100 μ f.