CN102023280B

CN102023280B - Measuring circuit for thyristor operating angle and triggering angle of alternating-current resistance welder

Info

Publication number: CN102023280B
Application number: CN 201010522520
Authority: CN
Inventors: 张忠典; 李冬青; 梅冬胜; 朱世良; 汤有良; 邱建明; 罗斌
Original assignee: Harbin Institute of Technology
Current assignee: Harbin Institute of Technology
Priority date: 2010-10-28
Filing date: 2010-10-28
Publication date: 2012-09-05
Anticipated expiration: 2030-10-28
Also published as: CN102023280A

Abstract

The invention discloses a measuring circuit for a thyristor operating angle and a triggering angle of an alternating-current resistance welder and relates to a measuring circuit for a thyristor operating angle and a triggering angle, solving the problem that the operating angle and the triggering angle of the traditional alternating-current welder are differently detected. In the invention, a current signal and a voltage signal are sent to a comparer to be compared so as to obtain respective half frequency waveforms, a current signal high-level time value is obtained according to the half frequency waveforms, and the time value is processed to obtain the operating angle. The obtained half frequency waveforms are broadened respectively, then signals obtained after broadening are respectively processed by a trigger to output waveforms, a time interval between voltage and current zero according to the output waveforms, and the time is processed to obtain the triggering angle. The measuring circuit is suitable for measuring the thyristor operating angle and the triggering angle of the alternating-current resistance welder.

Description

The metering circuit of AC resistance welding machine thyristor operating angle and trigger angle

Technical field

The present invention relates to the metering circuit of a kind of thyristor operating angle and trigger angle.

Background technology

The on-the-spot resistance welder 90% that uses of industrial welding is an AC welding set, and the secondary pressure drop of this kind welding machine is bigger, its actual use have only several volts.This welding machine can cause the lot of energy loss; Its main energy loss is on its secondary cable, because the long-term use of secondary cable can cause the change of impedance property; This change can cause the performance of welding machine various aspects to descend, and also welding quality is caused very big influence simultaneously.At present, measure very inconvenience at the dynamic resistance of the on-the-spot welding machine of welding, the measurement of its silicon controlled conduction angle and trigger angle is also very difficult, has a strong impact on the monitoring of welding quality.

Summary of the invention

The present invention is the problem for the detection difficult that solves existing AC welding set silicon controlled conduction angle and trigger angle, thereby the metering circuit of a kind of AC resistance welding machine thyristor operating angle and trigger angle is provided.

The metering circuit of AC resistance welding machine thyristor operating angle and trigger angle, it comprises resistance R 1, No. two resistance R 2, No. three resistance R 3, No. four resistance R 4, No. five resistance R 5, No. six resistance R 6, No. seven resistance R 7, No. eight resistance R 8, No. nine resistance R 9, No. ten

resistance R

10,11, ten No. two resistance R of ride on Bus No. 11 resistance R 12, capacitor C 1, No. two capacitor C 2, No. three capacitor C 3, No. four capacitor C 4, No. five capacitor C 5, No. six capacitor C 6, No. seven capacitor C 7, No. eight capacitor C 8, a diode D1, No. two diode D2, No. three diode D3, No. four diode D4, a comparer A1, No. two comparer A2, a chip U1, No. two chip U2, No. three chip U3 and No. four chip U4; One end of a resistance R 1 is connected with the original edge voltage signal end of AC resistance welding machine, and the other end of a said resistance R 1 is connected with the anode of the negative electrode of an end of a capacitor C 1, a diode D1, No. two diode D2 and the reverse input end of a comparer A1 simultaneously; The other end of a capacitor C 1 is connected with an end of power supply ground and No. two resistance R 2 simultaneously; The other end of No. two resistance R 2 is connected with the negative electrode of No. two diode D2 and the positive input of a comparer A1 simultaneously; The anode of a diode D1 is connected with an end of No. three resistance R 3; Another termination positive source of No. three resistance R 3; The forward power end of a comparer A1 is connected with an end of positive source and No. three capacitor C 3 simultaneously, and the other end of said No. three capacitor C 3 is connected with power supply ground; The negative sense power end of a comparer A1 is connected with an end of power cathode and No. two capacitor C 2 simultaneously, and the other end of said No. two capacitor C 2 is connected with power supply ground; The power supply ground end of a comparer A1 is connected with power supply ground; The output terminal of a comparer A1 is connected with an end of an end of No. four resistance R 4, No. four capacitor C 4 and the pin A of a chip U1 simultaneously, and the pin RC of a said chip U1 is connected with an end of No. five resistance R 5 and an end of No. five capacitor C 5 simultaneously; The other end of said No. five resistance R 5 is connected with the other end of No. four resistance R 4 with+5V power supply simultaneously, and the other end of said No. four capacitor C 4 is connected with power supply ground; The other end of No. five capacitor C 5 is connected with the pin C of a chip U1; The pin B of a said chip U1 is connected with the pin of a chip

; The pin CLR of a said chip U1 is connected with an end of No. six resistance R 6, and the other end of said No. six resistance R 6 is connected with+5V power supply; The pin Q of a chip U1 is connected with the pin R of No. four chip U4; The CLK of No. four chip U4 is connected with the pin D of power supply ground and No. four chip U4 simultaneously; The pin Q of No. four chip U4 is the trigger angle signal output part; One end of No. seven resistance R 7 is connected with the primary current signal end of AC resistance welding machine, and the other end of said No. seven resistance R 7 is connected with the anode of the negative electrode of an end of No. six capacitor C 6, No. three diode D3, No. four diode D4 and the positive input of No. two comparer A2 simultaneously; The other end of No. six capacitor C 6 is connected with an end of power supply ground and No. eight resistance R 8 simultaneously; The other end of No. eight resistance R 8 is connected with the anode of No. three diode D3 and the reverse input end of No. two comparer A2 simultaneously; The negative electrode of No. four diode D4 is connected with an end of No. nine resistance R 9, and the other end of said No. nine resistance R 9 is connected with power cathode; The output terminal of No. two comparer A2 is connected with an end of an end of No. ten resistance R 10, No. seven capacitor C 7 and the pin A of No. two chip U2 simultaneously; The other end of said No. ten resistance R 10 is connected with+5V power supply, and the other end of No. seven capacitor C 7 is connected with power supply ground; The power supply ground end of No. two comparer A2 is connected with power supply ground; The pin RC of No. two chip U2 is connected with an end of ride on Bus No. 11 resistance R 11 and an end of No. eight capacitor C 8 simultaneously; The other end of said No. eight capacitor C 8 is connected with the pin C of No. two chip U2; The other end of ride on Bus No. 11 resistance R 11 is connected with+5V power supply; The pin B of No. two chip U2 is connected with the pin of No. two chip U2

; The pin CLR of No. two chip U2 is connected with an end of ten No. two resistance R 12, and the other end of said ten No. two resistance R 12 is connected with+5V power supply; The pin Q of No. two chip U2 is connected with the pin CLK of No. three chip U3 and the pin S of No. four chip U4 simultaneously; The pin of No. three chip U3

is connected with the pin D of No. three chip U3; The pin S of No. three chip U3 all is connected with power supply ground with pin R; The output terminal of No. two comparer A2 is the conduction angle signal output part.

Beneficial effect: circuit of the present invention can be measured AC resistance welding machine silicon controlled conduction angle and trigger angle simply and easily, and measuring accuracy is higher.

Description of drawings

Fig. 1 is a circuit diagram of the present invention; Fig. 2 is the synoptic diagram of unknown parameter and electric current, voltage relation before in the principle of the present invention part; Fig. 3 is the waveform synoptic diagram before and after the voltage process comparer in the circuit of the present invention; Fig. 4 is the waveform synoptic diagram before and after the electric current process comparer in the circuit of the present invention; Fig. 5 be in the circuit of the present invention voltage through the waveform synoptic diagram behind comparer and first chip; Fig. 6 is the waveform synoptic diagram behind electric current process comparer, differential and second chip in the circuit of the present invention; Fig. 7 is the two divided-frequency signal waveform synoptic diagram of exporting in the circuit of the present invention; Fig. 8 is the waveform synoptic diagram of the trigger angle of circuit of the present invention.

Embodiment

Embodiment one, combination Fig. 1 explain this embodiment; The metering circuit of AC resistance welding machine thyristor operating angle and trigger angle, it comprises resistance R 1, No. two resistance R 2, No. three resistance R 3, No. four resistance R 4, No. five resistance R 5, No. six resistance R 6, No. seven resistance R 7, No. eight resistance R 8, No. nine resistance R 9, No. ten

resistance R

The difference of the metering circuit of embodiment two, this embodiment and embodiment one described AC resistance welding machine thyristor operating angle and trigger angle is that the model of a comparer A1 and No. two comparer A2 all is LM319.

The difference of the metering circuit of embodiment three, this embodiment and embodiment one described AC resistance welding machine thyristor operating angle and trigger angle is that a chip U1 and No. two chip U2 all are that model is the double precision monostalbe trigger of CD4538.

The difference of the metering circuit of embodiment four, this embodiment and embodiment one described AC resistance welding machine thyristor operating angle and trigger angle is that No. three chip U3 and No. four chip U4 all are that model is the trigger of CD4013.

Principle of work: referring to Fig. 2, wherein curve 1 is the welding current instantaneous value, and curve 2 is free component curves; The 3rd, the forced component curve; U is the supply voltage curve, and α is a trigger angle, and

is power-factor angle; θ is a conduction angle, and ψ is a drag angle.

At first the electric current and the voltage signal on the former limit of AC resistance welding machine are sent into two comparer LM319, relatively obtain two divided-frequency waveform separately.Can draw the time value of current signal high level thus, this time value just handled to draw conduction angle.The two divided-frequency waveform that obtains is carried out broadening separately through two CD4538 chips; Then the signal behind the broadening is passed through two 4013 chips; Voltage signal connects the R pin; Current signal connects the S pin, can measure the time interval of voltage and current between zero point by the waveform that the Q pin comes out, and is just handled can draw trigger angle this time.

Its concrete grammar is: at first the voltage and current signal of gathering is carried out comparison separately, the comparer of employing is LM319.LM319 has two input ends, and when the input value of positive input during greater than the input value of reverse input end, output valve is " 1 "; When the input value of positive input during less than the input value of reverse input end, output valve is " 0 ".Be to improve sampling precision, the voltage fiducial value is very little, be about about 0.2V, near voltage over zero very among a small circle in the generation high level, other scopes then are low level; The electric current incoming end is a positive, near current zero-crossing point, produces low level in very among a small circle, and other scopes then are high level.In order to prevent to disturb, all adopted electric capacity to carry out filtering at the input end of voltage and current signal, and the input end of LM319 chip all adopt two backward diodeds to carry out clamping protection.Fig. 3 is that voltage is that black is comparer waveform in the past through the waveform that the oscillogram before and after the comparer is positioned at the top, and the waveform that is positioned at the below is the later waveform of comparer.Fig. 4 is that electric current is that black is comparer waveform in the past through the waveform that the oscillogram before and after the comparer is positioned at the below, and the waveform that is positioned at the top is the later waveform of comparer.

In order to measure trigger angle and conduction angle accurately, it is all very little that the fiducial value of voltage and current is got, so it is also less to produce pulsewidth.When the measurement triggering angle, in order to prevent to disturb and loss of data, between LM319 and CD4013, connect one shot multivibrator CD4538, be used for the broadening pulsewidth.Fig. 5 is the oscillogram of voltage signal through comparer and CD4538 chip, and the squiggle that wherein is positioned at the below is the squiggle of voltage signal CD4538 chip; The squiggle that is positioned at the top is the squiggle of voltage signal through comparer.Fig. 6 is behind electric current process comparer, the differential and the squiggle of CD4538 chip; The squiggle that wherein is positioned at the top is that signal increases squiggle through the pulsewidth behind the CD4538; Squiggle in the middle of being positioned at is that current signal reduces the back squiggle through spike width behind the differential, and the squiggle that is positioned at the top is that signal is through two divided-frequency squiggle behind the comparer.The width of broadening is regulated through changing resistance R 5, R11 and capacitor C 5, C8.

Signal gets into CD4013 later on through CD4538; The pin Q output signal of CD4013 is the two divided-frequency signal; Waveform is as shown in Figure 7; The squiggle that wherein is positioned at the top is the squiggle of the pin Q output signal of the 3rd chip U3, and the squiggle that is positioned at the below is the squiggle of the pin Q output signal of CD4538 chip.

The other end of four-core sheet U4, the pulsewidth of the high level of the signal of pin Q output multiply by the supplementary angle that the clock period is exactly a trigger angle, deducts the value that this value has just drawn trigger angle with 180 then.Its time goes up with two pin Q output signal corresponding relations of the first chip U1 and the second chip U2 as shown in Figure 8; The curve that wherein is positioned at the top is the output waveform figure of the pin Q of four-core sheet U4; The curve of the side of being arranged in is the output waveform figure of the pin Q of the first chip U1, and the curve that is positioned at the top is the output waveform figure of the pin Q of the second chip U2.

Claims

1. the metering circuit of AC resistance welding machine thyristor operating angle and trigger angle, it is characterized in that: it comprises a resistance (R1), No. two resistance (R2), No. three resistance (R3), No. four resistance (R4), No. five resistance (R5), No. six resistance (R6), No. seven resistance (R7), No. eight resistance (R8), No. nine resistance (R9), No. ten resistance (R10), ride on Bus No. 11 resistance (R11), ten No. two resistance (R12), an electric capacity (C1), No. two electric capacity (C2), No. three electric capacity (C3), No. four electric capacity (C4), No. five electric capacity (C5), No. six electric capacity (C6), No. seven electric capacity (C7), No. eight electric capacity (C8), a diode (D1), No. two diodes (D2), No. three diodes (D3), No. four diodes (D4), a comparer (A1), No. two comparers (A2), a chip (U1), No. two chips (U2), No. three chips (U3) and No. four chips (U4); One end of a resistance (R1) is connected with the original edge voltage signal end of AC resistance welding machine, and the other end of a said resistance (R1) is connected with an end of an electric capacity (C1), the negative electrode of a diode (D1), the anode of No. two diodes (D2) and the reverse input end of a comparer (A1) simultaneously; The other end of an electric capacity (C1) is connected with the end of power supply ground with No. two resistance (R2) simultaneously; The other end of No. two resistance (R2) is connected with the negative electrode of No. two diodes (D2) and the positive input of a comparer (A1) simultaneously; The anode of a diode (D1) is connected with an end of No. three resistance (R3); Another termination positive source of No. three resistance (R3); The forward power end of a comparer (A1) is connected with the end of positive source with No. three electric capacity (C3) simultaneously, and the other end of said No. three electric capacity (C3) is connected with power supply ground; The negative sense power end of a comparer (A1) is connected with the end of power cathode with No. two electric capacity (C2) simultaneously, and the other end of said No. two electric capacity (C2) is connected with power supply ground; The power supply ground end of a comparer (A1) is connected with power supply ground; The output terminal of a comparer (A1) is connected with an end of No. four resistance (R4), an end of No. four electric capacity (C4) and the pin A of a chip (U1) simultaneously, and the pin RC of a said chip (U1) is connected with an end of No. five resistance (R5) and an end of No. five electric capacity (C5) simultaneously; The other end of said No. five resistance (R5) is connected with the other end of No. four resistance (R4) with+5V power supply simultaneously, and the other end of said No. four electric capacity (C4) is connected with power supply ground; The other end of No. five electric capacity (C5) is connected with the pin C of a chip (U1); The pin B of a said chip (U1) is connected with the pin of a chip

; The pin CLR of a said chip (U1) is connected with an end of No. six resistance (R6), and the other end of said No. six resistance (R6) is connected with+5V power supply; The pin Q of a chip (U1) is connected with the pin R of No. four chips (U4); The CLK of No. four chips (U4) is connected with the pin D of power supply ground with No. four chips (U4) simultaneously; The pin Q of No. four chips (U4) is the trigger angle signal output part; One end of No. seven resistance (R7) is connected with the primary current signal end of AC resistance welding machine, and the other end of said No. seven resistance (R7) is connected with an end of No. six electric capacity (C6), the negative electrode of No. three diodes (D3), the anode of No. four diodes (D4) and the positive input of No. two comparers (A2) simultaneously; The other end of No. six electric capacity (C6) is connected with the end of power supply ground with No. eight resistance (R8) simultaneously; The other end of No. eight resistance (R8) is connected with the anode of No. three diodes (D3) and the reverse input end of No. two comparers (A2) simultaneously; The negative electrode of No. four diodes (D4) is connected with an end of No. nine resistance (R9), and the other end of said No. nine resistance (R9) is connected with power cathode; The output terminal of No. two comparers (A2) is connected with an end of No. ten resistance (R10), an end of No. seven electric capacity (C7) and the pin A of No. two chips (U2) simultaneously; The other end of said No. ten resistance (R10) is connected with+5V power supply, and the other end of No. seven electric capacity (C7) is connected with power supply ground; The power supply ground end of No. two comparers (A2) is connected with power supply ground; The pin RC of No. two chips (U2) is connected with an end of ride on Bus No. 11 resistance (R11) and an end of No. eight electric capacity (C8) simultaneously; The other end of said No. eight electric capacity (C8) is connected with the pin C of No. two chips (U2); The other end of ride on Bus No. 11 resistance (R11) is connected with+5V power supply; The pin B of No. two chips (U2) is connected with the pin

of No. two chips (U2); The pin CLR of No. two chips (U2) is connected with an end of ten No. two resistance (R12), and the other end of said ten No. two resistance (R12) is connected with+5V power supply; The pin Q of No. two chips (U2) is connected with the pin CLK of No. three chips (U3) and the pin S of No. four chips (U4) simultaneously; The pin of No. three chips (U3)

is connected with the pin D of No. three chips (U3); The pin S of No. three chips (U3) all is connected with power supply ground with pin R; The output terminal of No. two comparers (A2) is the conduction angle signal output part;

A chip (U1) and No. two chips (U2) all are that model is the double precision monostalbe trigger of CD4538;

No. three chips (U3) and No. four chips (U4) all are that model is the trigger of CD4013.

2. the metering circuit of AC resistance welding machine thyristor operating angle according to claim 1 and trigger angle is characterized in that the model of a comparer (A1) and No. two comparers (A2) all is LM319.