control DC110 motor

[whung.john]

hi ,all my friends.
because i think use DC110 motor to control a machine.
i uses electric parts follow as;
from pic16f73 to moc3023,and use moc3023 control triac .
use triac part to control my dc110 motor.
but i dont understand ,how to write program.
i tried written porgram.and not use ccp1 direct to control DC110 motor.
i used pin A1 to connect motor.
please tell me ,where have bug error.

very thanks u read my question contents.

#define PWM_PIN PIN_a1
#define LOOPCNT 50
int8 width;

#INT_RTCC
void tick_interrupt(void);

//====================================
main()
{
width = 10;
setup_counters(RTCC_INTERNAL, RTCC_DIV_1);
enable_interrupts(INT_RTCC);
enable_interrupts(GLOBAL);

while(1)
{

}

}

//====================================
#INT_RTCC
void tick_interrupt(void)
{
static int8 loop = LOOPCNT;
static int8 pulse;

if(--loop == 0)
{
loop = LOOPCNT;
pulse = width;
}

if(pulse)
{
output_high(PWM_PIN);
pulse--;
}
else
{
output_low(PWM_PIN);
}

}

[ckielstra]

110VDC or 110VAC ?
I don't think you can use a triac for regulating a DC motor. Once triggered a triac will only shut down when the current goes down to zero, this will never happen with a DC voltage.

If you meant AC, then you will need some kind of synchronization to the power supply zero crossings.

[whng.john]

[ckielstra]

Even when using a rectifier bridge the DC voltage will continously vary from 0 Volts to the maximum. To get a stable motor regulation you will need some kind of synchronization with the mains voltage.

I'm no expert in this area. Maybe someone else can jump in?

[SherpaDoug]

ckielstra is right. If you try to use an unsynchronized PWM to control AC by a triac you will get a "beat note" as the AC and PWM clocks creep into and out of synchronization. I suggest you try these:
1) Get comfortable using PWM control of a small DC motor like in a toy car.
2) Try using a triac to control a 110VAC incandescent light bulb. A light bulb is a very easy load to drive, with minimal inertia, power changes are obvious, and it is electrically rugged and easy to replace if you find a way to damage it. Look at Microchip application note AN521 to see how to synchronize the PIC to the AC power line. I suggest you invest in an isolation transformer so you don't get shocked or blow up your PIC equipment if you touch a wrong wire.
3) Try controlling an AC brush motor like a lawn mower or vacuum cleaner motor.
4) Finally try your rectified AC drive of a DC motor.
_________________
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[WHUNG.JOHN]