Need a new laser (3V-5V)

[jollymolly]

Had these type of laser pointers.

They work on 3 1.5V batteries, I was using 5V from arduino. Could I have burned them out?

They still work but brightness has reduced significantly. They were working fine at 5V for a while.

Anyway I am now looking for a new laser, many of them use 2 1.5V batteries so
how would you power 3V with 5V power supply?

 

[jollymolly]

can anyone help?

 

[Moistenator]

You would need to drop down the current from 5v to 3v using a load. It's not all about the voltage, It's about the current. Make sure you only use as much current as both batteries would have together. Too much current and you'll kill your lasers if you haven't already.

 

[Bionic-Badger]

You should really post these types of questions in the Tutorial and Help forum, not the general forum.

As for your problem, 3 x 1.5V = 4.5V, so it's possible you could have burnt it out with 5V.

Since you're in the UK, just get a new red laser module from OdicForce. These use 3.5-6V, so 5V should work. For powering stuff with 3V from 5V try putting some diodes in series with the module. If you don't know what that means, you should study more basic electronics and then you'll know what to do.

 

[jollymolly]

Damn, Just ordered some laser pointers from amazon and ebay.

This one (2x1.5V)

and these (3x1.5V)

Are they any use?

I was going to modulate them through the power supply.
Can I use a resistor if I know the current they draw at 3V and 4.5V respectively.
for example resistance = 5V-4.5V /(current draw).

 

[Bionic-Badger]

You should probably use diodes to drop the voltage (high speed if you want to modulate with them), as those laser modules probably already have current-regulating drivers.

Oh, and your Arduino may not be able to supply enough current to power that green laser.

 

[jollymolly]

really?

My old red laser used about 40mA. Do green lasers need so much more?

This page suggests a current of 250mA.

I think the arduino could handle that.
If not I have access to a bench power supply that I can use.

Also how is using a diodes better than just a resistor?
will 1n4001 diode do when modulating laser?

 

[jollymolly]

Just received the green laser.

Holymoly it is bright ! my eyes hurt that's how bright!

Tested it at 3V, current draw was about 0.33A.

It says max power <5mW on it and class III

Is it dangerous to look at reflection? cause it seems to reflect from many surfaces.

 

[scumbagatheist]

Oy Vey! Why did you not buy safety goggles whilst purchasing all of your laser modules??

Of course your eyes hurt...You're burning your retinas! Put down the toys, right now, and get yourself some protective eye wear!

Clearly, you've not read or researched enough to be handling high powered lasers. Turn down your pot until it's a can toy. Get some goggles and protect yourself!

I say this not to chastise you, but to ensure you learn how to SAFELY use lasers.

 

[jollymolly]

What?

But I though 5mW lasers were safe aslong as you don't look at them directly.

 

[jollymolly]

The green laser is now projecting a faint red light, this is infrared correct? and dangerous.

Does this mean it is always emitting infrared. really scary now that I think about it.

 

[Bionic-Badger]

Yes, it is always projecting that, and it is FAR more powerful than its brightness would lead you to believe. Try breaking out a digital camera and see if you can see the spot it produces.