Multiple dimmers not working on Arduino UNO

[vibhoregit]

When connecting multiple lamps, there is interference in brightness, changing the power of one lamp changes the other. Even two dimmer are not working properly. Refer the example below:
`
#include <RBDdimmer.h>

//#define USE_SERIAL SerialUSB //Serial for boards whith USB serial port
#define USE_SERIAL Serial
#define Ch0 3
#define Ch1 9
int ch_sel;
int ch_pow;
#define zerocross 2 // for boards with CHANGEBLE input pins
dimmerLamp dimmer0(Ch0);
dimmerLamp dimmer1(Ch1);
void setup() {
USE_SERIAL.begin(9600);
dimmer0.begin(NORMAL_MODE, ON); //dimmer initialisation: name.begin(MODE, STATE)
dimmer1.begin(NORMAL_MODE, ON);
USE_SERIAL.println("Lamp Controller - 1 Online");
}
void loop() {
if (USE_SERIAL.available()) {
char ch = USE_SERIAL.read();
if (ch == '#') {
ch_sel = USE_SERIAL.parseInt();
ch_pow = USE_SERIAL.parseInt();
if (ch_pow <= 100 && ch_pow >= 0) {
switch (ch_sel) {
case 0:
dimmer0.setPower(ch_pow);
break;
case 1:
dimmer1.setPower(ch_pow);
break;
default:
USE_SERIAL.println("Error 1");
break;
}
delay(20);
USE_SERIAL.print(ch_sel);
USE_SERIAL.print(',');
USE_SERIAL.println(ch_pow);
USE_SERIAL.flush();
}
else
USE_SERIAL.println("Error 2");
} else
{
USE_SERIAL.read();
}
}
}
`