CN205283091U - Application specific integrated circuit of A -type low -voltage leakage protector - Google Patents

Abstract

The utility model provides an application specific integrated circuit of A -type low -voltage leakage protector, millivolt level electric leakage signal IN1 wherein, behind the IN2 voltage lifting times the more tertiary difference operational amplifier via the amplifier circuit in enlarge the differential signal and output for the enlarged output signal OA of difference, integrated circuit's external power voltage VCC via resistive voltage divider, carry out relatively determining whether excessive pressure by this partial pressure of hysteresis voltage comparator sampling among the over - voltage detection circuit and as incoming signal vop and reference voltage source and constant voltage power supply's reference voltage vref, output signal OA and reference voltage source and constant voltage power supply are enlargied to the difference the reference voltage vref voltage comparater in through delay circuit carries on relatively determining whether effective leak electricity the signal. The utility model discloses can detect AC simultaneously and exchange electric leakage signal and pulsating direct current electric leakage signal (being A type electric leakage signal), can repeat the accuracy and prolong time -charactaristic function, still have the function that the valid output drive keeps, improve anti -interference ability.

Description

A kind of A type low-voltage leakage protector application specific integrated circuit

Technical field

The utility model belongs to low-voltage leakage protector technical field, specifically relates to a kind of A type low-voltage leakage protector application specific integrated circuit.

Background technology

The GENERAL TYPE low-voltage leakage protector application specific integrated circuit that in existing market, application quantity is bigger does not have or asynchronously has the detection of A type electric leakage signal, superpotential protection (OVP), effectively exports maintenance and time delay function, and this kind of circuit can only be applied to AC ac leakage signal or the earth leakage protective device without time delay function. Market has occurred the so-called time delay earth leakage protective device of a kind of above-mentioned circuit production; owing to its delay capacitor does not have discharge path; can only slowly naturally discharge; cause charging initial value when every time carrying out electric leakage signal different like this; each delay value is also just different; the tolerance range of time delay is inadequate, the situation of not time delay even also may occurs. More seriously, when having undesired signal and delay capacitor has electricity to exist, earth leakage protective device will make a mistake action, makes the electrical network can not normal power supply. Nearly all earth leakage protective device application specific integrated circuit all keeps function without effectively exporting; due to the unstable of electrical network and the complicacy of power utilization environment; when electric circuit inspection electric leakage signal effective in non-continuous; earth leakage protective device cannot export enough pulsewidth actuate signals to be guaranteed to drive level continuous and effective to cutting off the electricity supply, and have effectively export the unicircuit keeping function can effective head it off. At present; overwhelming majority earth leakage protective device application specific integrated circuit does not have superpotential protection (OVP) function; when because of the abnormal maximum voltage working value causing outside service voltage to exceed regulation; accurately cannot judge abnormal and report to the police in time or Direct driver earth leakage protective device disconnection power supply by determination and analysis; circuit for electric leakage protector and load equipment is easily caused because of overload damage or to cause electrical fire accident, and the circuit with superpotential protection (OVP) function can effectively solve overvoltage problem.

Summary of the invention

The utility model mainly solves the technical problem existing for above-mentioned prior art, it provides a kind of A type low-voltage leakage protector application specific integrated circuit.

Above-mentioned technical problem of the present utility model is mainly solved by following technical proposals: a kind of A type low-voltage leakage protector application specific integrated circuit, it is characterized in that described unicircuit comprises amplification circuit, time delay circuit, overvoltage detection circuit, reset circuit, voltage stabilized source, votage reference source, vibrator, counter, latch and SCR driving mechanism, wherein millivolt level electric leakage signal IN1, via the three grades of difference operational amplifiers amplified in circuit difference signal amplified again after IN2 voltage lifting some times and export as differential amplification output signal OA, differential amplification output signal OA external capacitor filtering interfering, prevent city's electrical interference from causing tripping operation flase operation,

In overvoltage detection circuit, the outside service voltage VCC of unicircuit is via electric resistance partial pressure, hysteresis voltage comparator is sampled this dividing potential drop and is compared as the reference voltage Vref of input signal Vop and votage reference source and voltage stabilized source, when input signal Vop dividing potential drop is higher than reference voltage Vref, hysteresis voltage comparator exports as high level, no matter whether electric leakage signal exists, and hysteresis voltage comparator all triggers SCR driving mechanism action, and the output terminal OS of SCR driving mechanism is high level; When input signal Vop dividing potential drop is lower than reference voltage Vref, hysteresis voltage comparator exports as lower level, and now the OS of SCR driving mechanism exports only relevant with electric leakage signal;

The reference voltage Vref outputing signal OA and votage reference source and voltage stabilized source by differential amplification is compared by the voltage comparator in time delay circuit, when differential amplification outputs signal OA voltage lower than reference voltage Vref, voltage comparator exports as lower level, now the DLY pin of time delay circuit is discharge condition, time delay comparer no-output, SCR driving mechanism is failure to actuate, and its output terminal OS is lower level, when differential amplification outputs signal OA voltage higher than reference voltage Vref, voltage comparator exports as high level, now the DLY pin of time delay circuit is charging state, DLY pin is to external capacitor charging, until DLY pin voltage rise to during higher than reference voltage Vref, time delay comparer exports high level CountEn, SCR driving mechanism action, its output terminal OS is high level, latches output state and count internal device start counting simultaneously, the counting cycle of counter is 30 milliseconds, during 30 milliseconds of countings, the output state of latches is constant, to be counted complete after latch receive time delay comparer Output rusults and according to latch content determine OS state.

Counter and latch in circuit match, once the output terminal OS of SCR driving mechanism is high level, latches exports state, hereafter no matter whether time delay comparer also has effectively exports, can ensure that the minimum output driving time is more than or equal to 30ms, it is ensured that earth leakage protective device is effectively cut off the electricity supply; The adjustment of time delay time can be realized by changing the size of the external electric capacity of DLY pin, by constant current, this capacitor charging is ensured delay precision, by discharge loop, electric capacity is discharged in time, the starting voltage of electric capacity when charging every time is identical, achieve the function that can repeat time delay, also play the effect ensureing delay precision simultaneously. The utility model has the function that can simultaneously detect AC ac leakage signal and pulsating direct current electric leakage signal (i.e. A type electric leakage signal), can repeat the function of accurate delay value, also have the function effectively exporting and driving and keep, it is to increase anti-interference performance; The utility model can also have time delay and the function without time delay, makes it to meet electrical network classification protection scheme to the technology of required supporting time lagged type and GENERAL TYPE low-voltage leakage protection isolating switch and specification of quality.

Accompanying drawing explanation

Fig. 1 is a kind of structural representation of the present utility model.

In figure, 1-difference operational amplifier, 2-voltage stabilized source, 3-votage reference source, 4-voltage comparator, 5-time delay comparer, 6-latch, 7-counter, 8-vibrator, 9-reset circuit, 10-SCR driving mechanism, 11-hysteresis voltage comparator.

Embodiment

Below by embodiment, and by reference to the accompanying drawings, the technical solution of the utility model is described in further detail.

Embodiment: a kind of A type low-voltage leakage protector application specific integrated circuit, it is characterized in that described unicircuit comprises amplification circuit, time delay circuit, overvoltage detection circuit, reset circuit, voltage stabilized source, votage reference source, vibrator, counter, latch and SCR driving mechanism, wherein millivolt level electric leakage signal IN1, via the three grades of difference operational amplifiers amplified in circuit difference signal amplified again after IN2 voltage lifting some times and export as differential amplification output signal OA, differential amplification output signal OA external capacitor filtering interfering, prevent city's electrical interference from causing tripping operation flase operation, in overvoltage detection circuit, the outside service voltage VCC of unicircuit is via electric resistance partial pressure, hysteresis voltage comparator is sampled this dividing potential drop and is compared as the reference voltage Vref of input signal Vop and votage reference source and voltage stabilized source, when input signal Vop dividing potential drop is higher than reference voltage Vref, hysteresis voltage comparator exports as high level, no matter whether electric leakage signal exists, and hysteresis voltage comparator all triggers SCR driving mechanism action, and the output terminal OS of SCR driving mechanism is high level, when input signal Vop dividing potential drop is lower than reference voltage Vref, hysteresis voltage comparator exports as lower level, and now the OS of SCR driving mechanism exports only relevant with electric leakage signal, the reference voltage Vref outputing signal OA and votage reference source and voltage stabilized source by differential amplification is compared by the voltage comparator in time delay circuit, when differential amplification outputs signal OA voltage lower than reference voltage Vref, voltage comparator exports as lower level, now the DLY pin of time delay circuit is discharge condition, time delay comparer no-output, SCR driving mechanism is failure to actuate, and its output terminal OS is lower level, when differential amplification outputs signal OA voltage higher than reference voltage Vref, voltage comparator exports as high level, now the DLY pin of time delay circuit is charging state, DLY pin is to external capacitor charging, until DLY pin voltage rise to during higher than reference voltage Vref, time delay comparer exports high level CountEn, SCR driving mechanism action, its output terminal OS is high level, latches output state and count internal device start counting simultaneously, the counting cycle of counter is 30 milliseconds, during 30 milliseconds of countings, the output state of latches is constant, to be counted complete after latch receive time delay comparer Output rusults and according to latch content determine OS state.

Counter and latch in circuit match, once the output terminal OS of SCR driving mechanism is high level, latches exports state, hereafter no matter whether time delay comparer also has effectively exports, can ensure that the minimum output driving time is more than or equal to 30ms, it is ensured that earth leakage protective device is effectively cut off the electricity supply; The adjustment of time delay time can be realized by changing the size of the external electric capacity of DLY pin, by constant current, this capacitor charging is ensured delay precision, by discharge loop, electric capacity is discharged in time, the starting voltage of electric capacity when charging every time is identical, achieve the function that can repeat time delay, also play the effect ensureing delay precision simultaneously. The utility model has the function that can simultaneously detect AC ac leakage signal and pulsating direct current electric leakage signal (i.e. A type electric leakage signal), can repeat the function of accurate delay value, also have the function effectively exporting and driving and keep, it is to increase anti-interference performance; The utility model can also have time delay and the function without time delay, makes it to meet electrical network classification protection scheme to the technology of required supporting time lagged type and GENERAL TYPE low-voltage leakage protection isolating switch and specification of quality.

Finally, it should be noted that above embodiment is only the more representational example of the utility model. Obviously, the utility model is not limited to above-described embodiment, it is also possible to have many distortion. Every any simple modification, equivalent variations and modification above embodiment done according to technical spirit of the present utility model, all should think and belong to protection domain of the present utility model.

Claims (1)

1. an A type low-voltage leakage protector application specific integrated circuit, it is characterized in that described unicircuit comprises amplification circuit, time delay circuit, overvoltage detection circuit, reset circuit, voltage stabilized source, votage reference source, vibrator, counter, latch and SCR driving mechanism, wherein millivolt level electric leakage signal IN1, via the three grades of difference operational amplifiers amplified in circuit difference signal amplified again after IN2 voltage lifting some times and export as differential amplification output signal OA, differential amplification output signal OA external capacitor filtering interfering, prevent city's electrical interference from causing tripping operation flase operation,

In overvoltage detection circuit, the outside service voltage VCC of unicircuit is via electric resistance partial pressure, hysteresis voltage comparator is sampled this dividing potential drop and is compared as the reference voltage Vref of input signal Vop and votage reference source and voltage stabilized source, when input signal Vop dividing potential drop is higher than reference voltage Vref, hysteresis voltage comparator exports as high level, no matter whether electric leakage signal exists, and hysteresis voltage comparator all triggers SCR driving mechanism action, and the output terminal OS of SCR driving mechanism is high level; When input signal Vop dividing potential drop is lower than reference voltage Vref, hysteresis voltage comparator exports as lower level, and now the OS of SCR driving mechanism exports only relevant with electric leakage signal;

The reference voltage Vref outputing signal OA and votage reference source and voltage stabilized source by differential amplification is compared by the voltage comparator in time delay circuit, when differential amplification outputs signal OA voltage lower than reference voltage Vref, voltage comparator exports as lower level, now the DLY pin of time delay circuit is discharge condition, time delay comparer no-output, SCR driving mechanism is failure to actuate, and its output terminal OS is lower level, when differential amplification outputs signal OA voltage higher than reference voltage Vref, voltage comparator exports as high level, now the DLY pin of time delay circuit is charging state, DLY pin is to external capacitor charging, until DLY pin voltage rise to during higher than reference voltage Vref, time delay comparer exports high level CountEn, SCR driving mechanism action, its output terminal OS is high level, latches output state and count internal device start counting simultaneously, the counting cycle of counter is 30 milliseconds, during 30 milliseconds of countings, the output state of latches is constant, to be counted complete after latch receive time delay comparer Output rusults and according to latch content determine OS state.