Is it possible to replace a LED (white) with a Laser diode/Laser diode with driver?

Meant for a school project, i need it to be simple enough so i dont need parts to modify it, preferably just taking a regular laser pointer in place of the LED.
I want to modify this circuit: http://www.555-timer-circuits.com/laser-ray-sound.html

nothinglabs6 years ago
actually - I can say pretty safely this will work.

the other's concerns are valid if you're trying to drive a diode directly - but a laser pointer already includes a driver.

if you use a -complete- standard red laser pointer (ie - not just taking out the diode) - that takes 3 x 1.5v cells - you can safely drive it directly at 5v.

I drive a laser pointer directly at 5v from a microcontroller in my project at:

https://www.instructables.com/id/Arduino-Laser-Show-with-Full-XY-Control/

the 1.5v batteries are more like 1.6v at full charge - so 5v isn't stretching it much.

the circuit says 6-12v - but also includes a current limiting resistor of 470ohms for the LED.

the 470ohm value is probably about right for driving the laser at 12v. I suspect it would light up at lower voltages - but maybe be dim.

if you're going for a lower voltage (let's say 6v) - I'd go with a lower value resistor - maybe 100ohm or so.

in general - I'd start with a higher value resistor - and then try smaller values - until the laser shines at about "normal" brightness. that way you shouldn't fry it.

good luck!
iceng6 years ago
It will be a lot easier to just build a driver circuit for your Laser, rather then trying to adapt a 5kHz 555 pulse oscillator to power a sensitive semiconducting diode Laser.
+1. Definitely. Diode lasers are REAL easy to trash.