venkates2218
Full Member level 6
If we replacing the TRIAC by relay to control motor means also need snubber..?
For clarification i'm asking,in the document which you provided about snubber,in many circuits they used the RC across the TRIAC,but here we are taking an tap after RESISTOR.
What's the difference between RC across TRIAC and taking TAPPING after RESISTOR..?
47n or 100 nF/275 VAC X2 capacitors from major manufacturers are starting below 50 cent, single quantity at catalog distributors.The X2 Capacitors cost 3 to 4 USD. Why not simply use 40A type snubberless TRIAC ?
Opto triac dV/dt sensitivity is the other point, and usually more critical. That's why a suggested a modified snubber/filter circuit in post #11. It's discussed in detail in the linked Onsemi application note. With a 220 ohm series resistor, it's absorbing transients across the triac to some extent and to a greater degree filtering the opto triac input voltage. The circuit proved useful for me, but it's surely not the only way.What's the difference between RC across TRIAC and taking TAPPING after RESISTOR..?
A snubber working for triac can't be completely wrong for relays. It will usually reduce contact arcing. Snubber in parallel to contacts is however producing a certain leakage current which may be unwanted in some applications, e.g. when switching LED or fluorescent lamps. But it should be o.k. for motor load.
Right, clearance and creepage distance ist too small for 300 VAC CAT II. The 3.96 mm connector family is mostly used for 230 VAC with a void pin position.Is it safe..?Because the terminal gap in the connector is too close..
Right, clearance and creepage distance ist too small for 300 VAC CAT II. The 3.96 mm connector family is mostly used for 230 VAC with a void pin position.
Notice that the clearance of a 230 V switching triac is even smaller, but it's expected to "overhead" fire during a surge voltage anyway, thus it makes no sense to design this circuit part for the overvoltage category.
View attachment 150730View attachment 150731
Code:#define XTAL_FREQ 20MHZ #include <xc.h> #include "delay.h" #include "lcd.h" // CONFIG1H #pragma config OSC = HS // Oscillator Selection bits (HS oscillator) #pragma config FCMEN = OFF // Fail-Safe Clock Monitor Enable bit (Fail-Safe Clock Monitor disabled) #pragma config IESO = OFF // Internal/External Oscillator Switchover bit (Oscillator Switchover mode disabled) // CONFIG2L #pragma config PWRT = ON // Power-up Timer Enable bit (PWRT disabled) #pragma config BOREN = OFF // Brown-out Reset Enable bits (Brown-out Reset disabled in hardware and software) #pragma config BORV = 3 // Brown Out Reset Voltage bits (Minimum setting) // CONFIG2H #pragma config WDT = OFF // Watchdog Timer Enable bit (WDT disabled (control is placed on the SWDTEN bit)) #pragma config WDTPS = 32768 // Watchdog Timer Postscale Select bits (1:32768) // CONFIG3H #pragma config CCP2MX = PORTC // CCP2 MUX bit (CCP2 input/output is multiplexed with RC1) #pragma config PBADEN = OFF // PORTB A/D Enable bit (PORTB<4:0> pins are configured as digital I/O on Reset) #pragma config LPT1OSC = OFF // Low-Power Timer1 Oscillator Enable bit (Timer1 configured for higher power operation) #pragma config MCLRE = ON // MCLR Pin Enable bit (MCLR pin enabled; RE3 input pin disabled) // CONFIG4L #pragma config STVREN = OFF // Stack Full/Underflow Reset Enable bit (Stack full/underflow will cause Reset) #pragma config LVP = OFF // Single-Supply ICSP Enable bit (Single-Supply ICSP disabled) #pragma config XINST = OFF // Extended Instruction Set Enable bit (Instruction set extension and Indexed Addressing mode disabled (Legacy mode)) // CONFIG5L #pragma config CP0 = OFF // Code Protection bit (Block 0 (000800-001FFFh) not code-protected) #pragma config CP1 = OFF // Code Protection bit (Block 1 (002000-003FFFh) not code-protected) #pragma config CP2 = OFF // Code Protection bit (Block 2 (004000-005FFFh) not code-protected) #pragma config CP3 = OFF // Code Protection bit (Block 3 (006000-007FFFh) not code-protected) // CONFIG5H #pragma config CPB = OFF // Boot Block Code Protection bit (Boot block (000000-0007FFh) not code-protected) #pragma config CPD = OFF // Data EEPROM Code Protection bit (Data EEPROM code-protected) // CONFIG6L #pragma config WRT0 = OFF // Write Protection bit (Block 0 (000800-001FFFh) not write-protected) #pragma config WRT1 = OFF // Write Protection bit (Block 1 (002000-003FFFh) not write-protected) #pragma config WRT2 = OFF // Write Protection bit (Block 2 (004000-005FFFh) not write-protected) #pragma config WRT3 = OFF // Write Protection bit (Block 3 (006000-007FFFh) not write-protected) // CONFIG6H #pragma config WRTC = OFF // Configuration Register Write Protection bit (Configuration registers (300000-3000FFh) not write-protected) #pragma config WRTB = OFF // Boot Block Write Protection bit (Boot block (000000-0007FFh) not write-protected) #pragma config WRTD = OFF // Data EEPROM Write Protection bit (Data EEPROM not write-protected) // CONFIG7L #pragma config EBTR0 = OFF // Table Read Protection bit (Block 0 (000800-001FFFh) not protected from table reads executed in other blocks) #pragma config EBTR1 = OFF // Table Read Protection bit (Block 1 (002000-003FFFh) not protected from table reads executed in other blocks) #pragma config EBTR2 = OFF // Table Read Protection bit (Block 2 (004000-005FFFh) not protected from table reads executed in other blocks) #pragma config EBTR3 = OFF // Table Read Protection bit (Block 3 (006000-007FFFh) not protected from table reads executed in other blocks) // CONFIG7H #pragma config EBTRB = OFF // Boot Block Table Read Protection bit (Boot block (000000-0007FFh) not protected from table reads executed in other blocks) #define relay_1 PORTDbits.RD0 /*Output control*/ #define triac_1 PORTDbits.RD3 /*Output control*/ #define triac_2 PORTCbits.RC5 void System_init(void) { TRISA = 0b00000011; PORTA = 0b00000011; ADCON1 = 0XFF; CMCON = 0X07; TRISB = 0b11111111; PORTB = 0b11111111; TRISC = 0b00000000; PORTC = 0b00000000; TRISD = 0b00000000; PORTD = 0b00000000; TRISE = 0X00; PORTE = 0X00; } void main(void) { System_init(); lcd_init(); //LCD initialize lcd_clear(); lcd_goto(1, 1); lcd_puts("Test_1"); while (1) { relay_1 = 1; DelayMs(300); DelayMs(300); DelayMs(300); while (1) { triac_2 = 0; DelayMs(50); triac_1 = 1; DelayMs(300); DelayMs(300); DelayMs(300); triac_1 = 0; DelayMs(50); triac_2 = 1; DelayMs(300); DelayMs(300); DelayMs(300); } } }
The induction motor is 230VAC with BIDIRECTIONAL operation and consuming 2A current.It having three wire 1.NEUTRAL,2.CLOCKWISE,3.ANTICLOCKWISE.
An capacitor with 15uF is connected across 2 and 3 wire.
I have to drive the motor in both direction for mixing purpose.
When I connected an induction bulb to check the operation of the TRIAC it working fine.But When I connect the motor means after few revolution,the TRIAC is burned out.
Replaced the both TRAIC and OPTOCOUPLER along with the defective one.but facingthe same issue...
Hi,
* missing junction dot at RL1
* missing power supply capacitor(s)
I recommend them to suppress transients when the ULN inside diode becomes conductive.
Why the ULN with unused 7 transitors and not a single transistor?
Why the optocoupler?
Do you use an extra isolated 12V supply just for the relay?
Klaus
Hi,
* missing junction dot at RL1
* missing power supply capacitor(s)
I recommend them to suppress transients when the ULN inside diode becomes conductive.
Why the ULN with unused 7 transitors and not a single transistor?
Why the optocoupler?
Do you use an extra isolated 12V supply just for the relay?
Klaus
The snubber is connected across input and output.Is their any possible of current flow from input to output..?
Is this circuit is wrong or advising not to use optocouplers for relay..?
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