This instructable is about the Paty-Like strobe effect or Stroboscopic Lamp using leds.
In the photo I used the arduino 5v through a transistor to demonstrate the use of an out-surce power for using more leds and more power.
The potentionmeter is there working through the code to control the speed of the blink from 10/1000 of the second to a whole second.

One more thing, the code is actually the code of the blink example in the arduino software with a little modification.

Step 1: You Will Need

As many Leds as you want, but you will need coresponding power suplay and matching transistor
1 X 220ohm resistor
1 X 10k Potentiometer
Few Cabels

Step 2: Leds

Connect the leds in a prallel connection, connect the (-) cathode to ground, connect the anode (+) to the emitter side of the transistor.
Connect the collector side of the transistor to V and the base to the arduino pin 13 through a 220ohm resistor.

Step 3: Potentiometer

Connect the potentiometer's left pin to Arduino's 5v pin, the right pin to GND and the mid pin to analog 0 (A0)

Step 4: The Code

/*<br>  Modified Blink Example for a Stroboscopib Lamp
 Created by Uria Dubinsky
 */
 
int led = 13;


// the setup routine runs once when you press reset:
void setup() {                
  // initialize the digital pin as an output.
  pinMode(led, OUTPUT);     
}


// the loop routine runs over and over again forever:
void loop() {
  int dd = map (analogRead (A0), 0, 1023, 10, 1000);  // Reads Potentiometer and maps it to an integer between 10 to 1000)
  digitalWrite(led, HIGH);   // turn the LEDs on (HIGH is the voltage level)
  delay(dd);               // wait for however long sets by the potentiometer
  digitalWrite(led, LOW);    // turn the LEDs off by making the voltage LOW
  delay(dd);               //  wait for however long sets by the potentiometer

Step 5: You Are Ready to Go...

Thats it, you are ready to go to the party...

I found that to find the best blink speed start from the festest, while it almost seems lighting continualy and start slowing down, the best speed is as fast as you but while you can see it blinking and notice the on/off clearly