Make a Simple Laser Diode Module

Laser diodes are quite useful in some ways especially in trigger/alarm systems such as triplight mechanisms or even in DIY toys if you just want to play with it. These two terminal devices are generally much more expensive than LEDs although technically speaking, they are both light emitting diodes. They just emit light in different ways. In some microcontroller projects, it can be used as an input/trigger to a photoresistor/phototransistor and in some cases, one may opt to use a supply that is not directly connected to the other components especially some delicate ICs or microcontrollers that cannot provide enough supply current. In this instructable, we are going to make a very simple module for any laser diode with a maximum forward voltage of about 4.5 Volts, supply it with a maximum of 20mA current (just like a typical LED) from an unregulated DC supply of 6V-18V or battery.”