SCR over 0 detection

Can be used in single-chip microcomputer controlled SCR circuit, can reduce the volume and weight of the product. ......

Why separate with R1, R2, R3? Are they all strung together, with a resistor?

Landlord has done 0 testing what to do with?
1, in order to increase security
2. Control the output power of SCR

If you need to be very precise, you can use a voltage comparator after the resistor is divided, then the Optocoupler
Landlord is in order to adjust the power bar, if not know how the landlord in terms of load

The latter is controlled by a single-chip SCR, control the brightness of the incandescent lamp
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Over 0 detection circuit
Resistance parameters verified, available


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My hardware circuit diagram:

citing recommendations based on the 5th floor Decai

Let's see this LM358 circuit done 0 detection, AC0 51 single-chip microcomputer INT0 non-, source http://bbs.mydigit.cn/read.php?tid=221794

Look at my program, it is, it is used to gradient when the light flashes, have not found the reason:
The reason found that the original was done 0 detection of the transformer received the load (incandescent) after the interruption caused by interference caused by the flashing signal!!
The program also slightly changed time parameters, stepless gradient, fade, see 26 floor Video effect, this program is very force:

See xinqi99 on 26th Floor, published on 2011-03-03 12:55:
Video Effects (00:02:31)

#include <reg52.h>
#define UINT unsigned int
#define UCHAR unsigned char
#define ON 0
#define OFF 1
....................................
void Main ()
{
Tmod = 0x11;
Ea=1;
tcon=0x05;
..................
for (;;)
{
Dispinfo ();
Display ();
Keyscan ();
}
}

..............................

void Keyscan ()
{
........................
if (s1_num==0)
{
if (s2==0)
Mdelay (10);
if (s2==0)
if (k_less30s>59)
{
Lampgradual ();
}
}
}
void Lampgradual ()
{
GRADUAL=LAMP1;
k_less30s=0; Press switch light key interval less than 30 seconds mark time long record
Ex0=1; Open External Interrupt 0
Et0=1;
Tr0=1;
Et1=1; Timer 1 Interrupt Allowed
It0=1; INT0 for Falling Edge (previously forgot this, the gradient is not light, hehe)
on_init=7000; The fade-out timing trigger is initialized to 10ms and decrements
off_init=4000; The fade-off timing trigger is initialized to 0ms and increments
}


//  ********************************************************************
void Timer0 () interrupt 1//real-time Clock interrupt program
{
th0= (65536-50000)/256;
tl0= (65536-50000)%256;
time50ms++;
if (time50ms==20)//real-time clock walking cumulative
{
time50ms=0;
sec++;
if (k_less30s<60)//| | Ontime==1 | | Offtime==1//*********** after the key or timing time to rear switch lights *************
{
k_less30s++;
if (k_less30s==30)//30 seconds after ********
{
k_less30s=60; Closed fade-off operation,
lamp1=~gradual;
ex0=0; 30 seconds off Interrupt
et1=0; 30 Seconds off Timer 1
et0=0;
tr0=0;
}
}
}
}


void int0_ac0 () interrupt 0//external interrupt 0,ac over 0 o'clock, 50Hz alternating current 100 times per second, 10ms each interval
{
Et1=1; Timer 1 Interrupt Allowed
tr1=0; Timer 1 Start Timer
if (Gradual==off)//Fade Away
{
--on_init;         on_init-=2; Per 10ms
A= (65536-on_init)/256; Timing Initial Value
b= (65536-on_init)%256;
}
if (gradual==on)//fade-off
{
++off_init; off_init+=2;
A= (65536-off_init)/256;
b= (65536-off_init)%256; //
}  //
Th1=a;
Tl1=b;
Tr1=1; Start timing
}

void Timer1 () interrupt 3//Timer 1 Interrupt program (light gradient phase shift control)
{
Uchar I;
Lamp1=on; Trigger Pulse of lamp 1
{
for (i=0;i<2;i++); Delay xμs
Lamp1=off;
}
}

////////////////
3063 is over 0 open, unable to adjust the conduction angle, the hardware will not be. Personal advice or a change of optocoupler.

This is to choose the 3020 series of non-0 detection of optocoupler, but I do not do hardware such, 3020 Peak voltage 400v do not know the pressure is not enough, the program I will not write, you can give you a thought, write your own program

You want an over 0 detection circuit, a thyristor trigger circuit, this you should not be a problem, the program, a half wave 10ms, you need a few levels of light to divide this 10ms several, not equal parts oh, or uneven dimming, you can experiment, I also say, each single-chip microcomputer detected over 0 signal is in, If you're going to drive the first few gears, you're going to send a trigger signal to the empty silicon circuit after a few seconds, and then wait for the next 0 signal.

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Over 0 inspection circuit

Release: | Author: | Source: Tianhaizhou | Viewed: 1598 times | User focus:

As shown in the above-mentioned design of the voltage forward over 0 detection circuit. 220V alternating current through the resistor partial pressure, then the photoelectric coupling, assuming that the input is a phase voltage, when a phase voltage from negative half-week to positive half-week conversion, the transistor conduction and work in saturation, will produce a descent along the pulse into the adμc812 INT0 pin to the system into the interrupt program. After the microcomputer system enters the interrupt program, emits the sampling command and reads the reactive current value from the sample-IQM, the reactive current is the reactive current of phase A, and after 1/4 cycles the voltage reaches the maximum, the voltage is sampled, and a UM is obtained by

As shown in the above-mentioned design of the voltage forward over 0 detection circuit. 220V alternating current through the resistor partial pressure, then the photoelectric coupling, assuming that the input is a phase voltage, when a phase voltage from negative half-week to positive half-week conversion, the transistor conduction and work in saturation, will produce a descent along the pulse into the adμc812 INT0 pin to the system into the interrupt program. After the microcomputer system enters the interrupt procedure, emits the sampling command and reads the reactive current value from the sample IQM, this reactive current is a phase of reactive current, after 1/4 cycle voltage reaches the maximum, at this time to sample the voltage, get UM, by um=1.414u can get the voltage RMS U.

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Over 0 detection circuit, if needed very precise can be used with a voltage comparator after the resistance divider

Over 0 of the resistance is only one 100K is very dangerous, or two 50K is better. The problem of power withstand voltage.
Because it is a two-way trigger, so the frequency is 100hz Oh, the basic can not see the flash

SCR over 0 detection