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How to: Homemade Light Strobe

Light strobes are used for entertainment in places like discos and parties. They are also used in warning and avoidance systems. A homemade light strobe can be made with an LED as a light source. An LED is a semiconductor that is specifically made to emit light. They come in many colors, including white, and some of them have high brightness, which makes them ideal for strobes. Along with the LED, place an audio transformer inside of the circuit, to help produce oscillations. Control the flashing rate with a potentiometer, which is a variable resistor.

Things You'll Need

LED
2N2222 transistor
Audio output transformer
330-ohm resistor
4.7k-ohm resistor
100k-ohm potentiometer
3.3uF capacitor
50uF capacitor
3 AA batteries
Battery holder
Breadboard
Jumper wires

Instructions

- 1
  Separate the three leads of the transistor so that they are slightly apart. Insert the transistor parallel to the breadboard so that all three leads fall into different columns.
- 2
  Add the transformer, but place it slightly apart from the transistor. All three of its input leads must also be placed into separate columns. The output leads on its back must remain disconnected.
- 3
  Select one row or column on the breadboard as the voltage source, and another as ground. Add a jumper wire between the middle lead of the transformer, which is called the center tap, and the voltage source row.
- 4
  Insert the negative lead of the LED, which is the shorter leg, into the same column that the transistor's collector lead is in. Insert the LED's positive lead into an empty column.
- 5
  Place the left end of the 330 resistor into this same column. Connect the right end of the resistor to the column that the transformer's right lead is in.
- 6
  Add the 3.3uF capacitor so that its negative lead is in the transistor's base column and its positive lead is in the transistor's emitter column. One way to do this is to place the capacitor a few rows down, and then use jumper wires to connect it to the column openings.
- 7
  Attach one end of the 4.7k resistor to the column that the 3.3uF capacitor's negative lead is in, which is also the transistor's base column. Attach the other end of the resistor to a different location.
- 8
  Add the wiper of the middle part of the potentiometer to this location. Wire one of the potentiometer's other leads to the voltage source, and place the other at ground.
- 9
  Insert the negative lead of the 50uF capacitor to the transistor's base column so that it is directly after the 47k resistor. Use a jumper wire and attach the capacitor's positive lead to the left end of the transformer.
- 10
  Place the batteries inside of the holder. Add the holder's black lead to ground and its red lead to the voltage source. The LED will begin blinking.
- 11
  Turn the potentiometer's knob to adjust the flash rate.

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