CN103956708B - Low-voltage direct load overload telemetry circuit - Google Patents

Abstract

The present invention relates to a kind of low-voltage direct load overload telemetry circuit.The present invention includes observing and controlling main circuit and overload judging circuit, specifically includes driver DR, DC load DL, IGCT VT1, metal-oxide-semiconductor VT2, voltage-stabiliser tube DW1, pressure limiting pipe DW2, comparator IC1, inductance L1, diode D1, power lights LED1, output lamp LED2, voltage regulation resistance R1, anode resistance R2, resistance R3, output resistance R4, gate electrode resistance R5, electric capacity of voltage regulation C1, filter capacitor C2, sets electric capacity C3 etc..The present invention utilizes the power field effect pipe of ultralow conducting resistance, both as current measuring element, also serve as circuit and turn off control element, the trace inductance in conjunction with the half control characteristic of IGCT and concatenated in load circuit and Quick circuit, realizing the overload of low-voltage direct load is detected in real time with short trouble, differentiated and security control, present configuration is simple, safe and reliable, low cost.

Description

Low-voltage direct load overload telemetry circuit

Technical field

The invention belongs to industrial measurement and control field, relate to a kind of circuit, loaded particularly to a kind of low-voltage direct Carry telemetry circuit, it is adaptable to need the overload to low-voltage direct load or short trouble detect in real time and pacify The occasion that full guard controls.

Background technology

In the power supply loaded to low-voltage direct with direct current driving power supply (also referred to as driver), often occur because of Load overload or be short-circuited phenomenon and damage direct current driving power supply and load itself, therefore, it is necessary to carry out right Overload and short trouble detect and safety protection control in real time.The most conventional effective ways are: pass through Respond rapid Hall current sensor load current is detected in real time, multilevel iudge, when exceeding safety Send instruction during threshold value, turn off driver and send warning instruction, to realize driver, DC load Safeguard protection.The method there is the problem that one is because when load overload or short trouble, electric current is very big, Therefore the power device capacity in driver to take bigger allowance, for the Hall current sensor of short-circuit detecting Range also to select big more more than running current, this makes cost the highest；Two is to send out for moment Raw short trouble, often has little time to protect the damage that just will result in internal drive power device.To this end, The overload that research cost is low, security is high and short trouble testing and control project have important technology and economic implications, And it is of many uses.

Summary of the invention

It is an object of the invention to the deficiency existed for prior art, propose a kind of low-voltage direct load overload and survey Control circuit.This circuit utilizes the power field effect pipe (MOSFET) of ultralow conducting resistance, both as current detecting Element, also turns off simultaneously as circuit and controls element, in conjunction with the half control characteristic of IGCT and in load circuit The trace inductance of concatenation and Quick circuit, can realize entering the overload of low-voltage direct load with short trouble Row detection in real time, differentiation and security control.

The present invention includes observing and controlling main circuit and overload judging circuit.

Observing and controlling main circuit include driver DR, inductance L1, diode D1, DC load DL, power lights LED1, Output lamp LED2, voltage-stabiliser tube DW1, pressure limiting pipe DW2, IGCT VT1, metal-oxide-semiconductor VT2, electric capacity of voltage regulation C1, Voltage regulation resistance R1, anode resistance R2, resistance R3, output resistance R4, gate electrode resistance R5, dividing potential drop electricity Positive output end+E the end of resistance R6, driver DR and one end of inductance L1, the negative electrode of diode D1, power supply The anode of lamp LED1, one end of anode resistance R2, one end of resistance R3, the sun of output lamp LED2 Pole connects, the negative output terminal-E end ground connection of driver DR, the negative electrode of power lights LED1 and voltage regulation resistance R1 One end connect, the other end of voltage regulation resistance R1 and the negative electrode of voltage-stabiliser tube DW1, one end of electric capacity of voltage regulation C1, One end of pull-up resistor R7, one end of reference resistance R8, the positive power source terminal V+ end of comparator IC1 connect, The anode of voltage-stabiliser tube DW1, the equal ground connection of the other end of electric capacity of voltage regulation C1, the other end of anode resistance R2 is with brilliant The anode of brake tube VT1, the negative electrode of pressure limiting pipe DW2, the other end of resistance R3, the grid of metal-oxide-semiconductor VT2 Extreme G end connects, the gate pole of IGCT VT1 and one end of gate electrode resistance R5, one end of divider resistance R6 Connect, the negative electrode of IGCT VT1, the other end of gate electrode resistance R5, the anode of pressure limiting pipe DW2 and MOS The equal ground connection of source terminal S end of pipe VT2, the drain electrode end D end of metal-oxide-semiconductor VT2 and one end of output resistance R4, Negative terminal-IN the end of DC load DL, one end of detection resistance R11 connect, the other end of output resistance R4 Is connected with the negative electrode of output lamp LED2, the anode+IN end of DC load DL and the other end of inductance L1, two The anode of pole pipe D1 connects.

Overload judging circuit include comparator IC1, pull-up resistor R7, reference resistance R8, set resistance R9, Filter resistance R10, detection resistance R11, filter capacitor C2, the ground end of setting electric capacity C3, comparator IC1 GND end ground connection, the positive input terminal IN+ end of comparator IC1 and the detection other end of resistance R11, filter resistance One end of R10, one end of filter capacitor C2 connect, the other end of filter resistance R10, filter capacitor C2 The equal ground connection of the other end, the negative input end IN-end of comparator IC1 and the other end of reference resistance R8, setting One end of resistance R9, one end of setting electric capacity C3 connect, and set the other end of resistance R9, set electric capacity The equal ground connection of the other end of C3, the output OUT terminal of comparator IC1 and the other end of divider resistance R6, on The other end of pull-up resistor R7 connects.

Beneficial effects of the present invention is as follows:

The present invention utilizes the power field effect pipe (MOSFET) of a ultralow conducting resistance, both as current detecting Element, also turns off simultaneously as circuit and controls element, in conjunction with the half control characteristic of IGCT and in load circuit The trace inductance of concatenation and Quick circuit, can realize the overload to low-voltage direct load and short trouble Detect in real time, Quick and security control.This circuit arrangement simple in construction, safe and reliable, cost Low, applied range.

Accompanying drawing explanation

Fig. 1 is the circuit diagram of the present invention.

Detailed description of the invention

The invention will be further described below in conjunction with the accompanying drawings.

As it is shown in figure 1, low-voltage direct load overload telemetry circuit, differentiate electricity including observing and controlling main circuit and overload Road.

Observing and controlling main circuit include driver DR, inductance L1, diode D1, DC load DL, power lights LED1, Output lamp LED2, voltage-stabiliser tube DW1, pressure limiting pipe DW2, IGCT VT1, metal-oxide-semiconductor VT2, electric capacity of voltage regulation C1, Voltage regulation resistance R1, anode resistance R2, resistance R3, output resistance R4, gate electrode resistance R5, dividing potential drop electricity Positive output end+E the end of resistance R6, driver DR and one end of inductance L1, the negative electrode of diode D1, power supply The anode of lamp LED1, one end of anode resistance R2, one end of resistance R3, the sun of output lamp LED2 Pole connects, the negative output terminal-E end ground connection of driver DR, the negative electrode of power lights LED1 and voltage regulation resistance R1 One end connect, the other end of voltage regulation resistance R1 and the negative electrode of voltage-stabiliser tube DW1, one end of electric capacity of voltage regulation C1, One end of pull-up resistor R7, one end of reference resistance R8, the positive power source terminal V+ end of comparator IC1 connect, The anode of voltage-stabiliser tube DW1, the equal ground connection of the other end of electric capacity of voltage regulation C1, the other end of anode resistance R2 is with brilliant The anode of brake tube VT1, the negative electrode of pressure limiting pipe DW2, the other end of resistance R3, the grid of metal-oxide-semiconductor VT2 Extreme G end connects, the gate pole of IGCT VT1 and one end of gate electrode resistance R5, one end of divider resistance R6 Connect, the negative electrode of IGCT VT1, the other end of gate electrode resistance R5, the anode of pressure limiting pipe DW2 and MOS The equal ground connection of source terminal S end of pipe VT2, the drain electrode end D end of metal-oxide-semiconductor VT2 and one end of output resistance R4, Negative terminal-IN the end of DC load DL, one end of detection resistance R11 connect, the other end of output resistance R4 Is connected with the negative electrode of output lamp LED2, the anode+IN end of DC load DL and the other end of inductance L1, two The anode of pole pipe D1 connects.

Overload judging circuit include comparator IC1, pull-up resistor R7, reference resistance R8, set resistance R9, Filter resistance R10, detection resistance R11, filter capacitor C2, the ground end of setting electric capacity C3, comparator IC1 GND end ground connection, the positive input terminal IN+ end of comparator IC1 and the detection other end of resistance R11, filter resistance One end of R10, one end of filter capacitor C2 connect, the other end of filter resistance R10, filter capacitor C2 The equal ground connection of the other end, the negative input end IN-end of comparator IC1 and the other end of reference resistance R8, setting One end of resistance R9, one end of setting electric capacity C3 connect, and set the other end of resistance R9, set electric capacity The equal ground connection of the other end of C3, the output OUT terminal of comparator IC1 and the other end of divider resistance R6, on The other end of pull-up resistor R7 connects.

Used in the present invention include IGCT VT1, metal-oxide-semiconductor VT2, comparator IC1, voltage-stabiliser tube DW1, Pressure limiting pipe DW2, power lights LED1, output lamp LED2 etc. all use existing ripe product at interior all devices Product, can be obtained by market.Such as: IGCT uses KP1-2, metal-oxide-semiconductor uses IRF series N-channel MOSFET manages, and comparator uses high speed voltage comparator LMV7239, and voltage-stabiliser tube uses BZX84-B5V1, limit Pressure pipe uses IN4746A, power lights, output lamp all to use 3-5mm light emitting diode etc..

Main circuit parameter coordination relation in the present invention is as follows:

In accompanying drawing 1, the driver outputting drive voltage U that the present invention is suitable for_dScope is+10V～+100V, base Quasi-resistance R8, the parameter coordination relation such as formula set between resistance R9, filter resistance R10, detection resistance R11 (1), shown in formula (2), filter capacitor C2, the parameter coordination relation such as formula (3) set between electric capacity C3 Shown in, wherein, U_WFor the voltage of voltage regulation (V) of voltage-stabiliser tube DW1, U_iElectricity when turning on for metal-oxide-semiconductor VT2 Stream detection signal (V), U_irSignal (V), R is set for current threshold_onFor metal-oxide-semiconductor VT2 conducting resistance (Ω), I_omMax-thresholds electric current (A) for overload with short-circuit protection.

$\frac{R10}{R10+R11}{U}_i=\frac{R9}{R8+R9}{U}_W=U_{\mathrm{ir}}---\left(1\right)$

U_i=R_onI_om(2)

$\frac{R10\×R11}{R10+R11}{C}_2=\frac{R8\×R9}{R8+R9}{C}_3---\left(3\right)$

The course of work of the present invention is as follows:

When driver DR outputting drive voltage, through the effect of voltage-stabiliser tube DW1, produce low pressure voltage of voltage regulation U_W As the power supply of the low-power consumption judging circuit based on comparator IC1, during because just powering on, no matter metal-oxide-semiconductor VT2 Whether turn on, because the effect of inductance L1 makes electric current not suddenly change, now comparator IC1 output low level, IGCT VT1 is off state, and therefore, metal-oxide-semiconductor VT2 turns on, hereafter, and the operation shape that circuit is possible State is as follows:

(1) circuit state during normal work: DC load DL obtains electric work, and load circuit electric current I_o Less than carrying out overload and the max-thresholds electric current I of short-circuit protection that protection controls_om, then comparator IC1 is always Output low level, IGCT VT1 is constantly in off state, and metal-oxide-semiconductor VT2 is also constantly in conducting state, Whole normal circuit operation；

(2) there is circuit state when overload or short circuit: when there is overload or load end short trouble, then After driver DR output voltage and metal-oxide-semiconductor VT2 conducting, through the cushioning effect of inductance L1 so that load Loop current I_oCan not suddenly change, and work as I_oGradually rise to max-thresholds electric current I_omTime, comparator IC1's is defeated High level is become from low level so that IGCT VT1 conducting, metal-oxide-semiconductor VT2 are also because of its gate-source on going into action Between voltage become low level from high level and turn off, this has cut off driver DR and DC load the most in time Contact between DL, hereafter, although I_oIt is zero so that the output of comparator IC1 changes to again low level, but Half control character (its gate pole can only control conducting, it is impossible to controls to turn off) due to IGCT VT1 so that MOS Pipe VT2 is held off, it is achieved thereby that to load overload or the safety protection control of short trouble.

Claims (3)

1. low-voltage direct load overload telemetry circuit, including observing and controlling main circuit and overload judging circuit, its feature It is:

Observing and controlling main circuit includes driver DR, inductance L1, diode D1, DC load DL, power lights LED1, output lamp LED2, voltage-stabiliser tube DW1, pressure limiting pipe DW2, IGCT VT1, metal-oxide-semiconductor VT2, steady Voltage capacitance C1, voltage regulation resistance R1, anode resistance R2, resistance R3, output resistance R4, gate pole electricity Resistance R5, divider resistance R6, the positive output end+E end of driver DR and one end of inductance L1, diode The negative electrode of D1, the anode of power lights LED1, one end of anode resistance R2, one end of resistance R3, The anode of output lamp LED2 connects, the negative output terminal-E end ground connection of driver DR, the moon of power lights LED1 Pole is connected with one end of voltage regulation resistance R1, the negative electrode of the other end of voltage regulation resistance R1 and voltage-stabiliser tube DW1, One end of electric capacity of voltage regulation C1, one end of pull-up resistor R7, one end of reference resistance R8, comparator IC1 Positive power source terminal V+ end connect, the anode of voltage-stabiliser tube DW1, the equal ground connection of the other end of electric capacity of voltage regulation C1, sun The other end of electrode resistance R2 and the anode of IGCT VT1, the negative electrode of pressure limiting pipe DW2, resistance R3 The other end, the gate terminal G end of metal-oxide-semiconductor VT2 connect, the gate pole of IGCT VT1 and gate electrode resistance R5 One end, divider resistance R6 one end connect, the negative electrode of IGCT VT1, gate electrode resistance R5 another End, the anode of pressure limiting pipe DW2 and the equal ground connection of source terminal S end of metal-oxide-semiconductor VT2, the drain electrode of metal-oxide-semiconductor VT2 Hold D end and one end of output resistance R4, the negative terminal-IN end of DC load DL, detect the one of resistance R11 End connects, and the other end of output resistance R4 is connected with the negative electrode of output lamp LED2, and DC load DL is just End+IN end is connected with the other end, the anode of diode D1 of inductance L1；

Overload judging circuit include comparator IC1, pull-up resistor R7, reference resistance R8, set resistance R9, Filter resistance R10, detection resistance R11, filter capacitor C2, setting electric capacity C3, the ground of comparator IC1 End GND end ground connection, the positive input terminal IN+ end of comparator IC1 and the detection other end of resistance R11, filtering One end of resistance R10, one end of filter capacitor C2 connect, the other end of filter resistance R10, filtered electrical Hold the equal ground connection of the other end of C2, the negative input end IN-end of comparator IC1 and the other end of reference resistance R8, The one end setting resistance R9, the one end setting electric capacity C3 connect, and set the other end of resistance R9, setting The equal ground connection of the other end of electric capacity C3, another of the output OUT terminal of comparator IC1 and divider resistance R6 End, the other end of pull-up resistor R7 connect.

2. low-voltage direct load overload telemetry circuit as claimed in claim 1, it is characterised in that: described IGCT VT1 uses KP1-2, metal-oxide-semiconductor VT2 to use IRF series N-channel MOS FET pipe, comparator IC1 uses high speed voltage comparator LMV7239, voltage-stabiliser tube DW1 to use BZX84-B5V1, pressure limiting pipe DW2 IN4746A, power lights LED1, output lamp LED2 is used all to use 3-5mm light emitting diode.

3. low-voltage direct load overload telemetry circuit as claimed in claim 1, it is characterised in that: described The driving voltage U of driver DR output_dScope is+10V～+100V, reference resistance R8, setting resistance Parameter coordination relation such as formula (1), formula (2) between R9, filter resistance R10, detection resistance R11 are shown, Shown in filter capacitor C2, the parameter coordination relation such as formula (3) set between electric capacity C3, wherein, U_WFor The voltage of voltage regulation (V) of voltage-stabiliser tube DW1, U_iCurrent detection signal (V) when turning on for metal-oxide-semiconductor VT2, U_ir Signal (V), R is set for current threshold_onFor metal-oxide-semiconductor VT2 conducting resistance (Ω), I_omFor overload with short The max-thresholds electric current (A) of road protection；

$\frac{R10}{R10+R11}{U}_i=\frac{R9}{R8+R9}{U}_W=U_{ir}---\left(1\right)$

U_i=R_onI_om (2)

$\frac{R10\×R11}{R10+R11}{C}_2=\frac{R8\×R9}{R8+R9}{C}_3---\left(3\right).$