Decreasing the current of a laser presentation pointer

Thread Starter

Mohd_Bash

Joined May 2, 2021
2
Dear all,

First of all I'm not an engineer, so sorry in advance if this is an engineer only forum.

I got a green laser pointer, and problem is that its too bright to be used in a dark room. I noted that once the battery started to die, the laser got dimmer and it was perfect.
My question: is there a simple and safe way to decrease the voltage of the 2 AAA batteries or increase the resistance of the circuit to decrease the current?

Thanks in advance
 

Yaakov

Joined Jan 27, 2019
3,522
Dear all,

First of all I'm not an engineer, so sorry in advance if this is an engineer only forum.

I got a green laser pointer, and problem is that its too bright to be used in a dark room. I noted that once the battery started to die, the laser got dimmer and it was perfect.
My question: is there a simple and safe way to decrease the voltage of the 2 AAA batteries or increase the resistance of the circuit to decrease the current?

Thanks in advance
My first thought would be to use NiMH batteries which have a terminal voltage of only 1.2V instead of the 1.5 of alkaline types, with the added benefit of recharagability. My second thought would be to use an optical filter to decrease the beam intensity.

My third thought would be to pull to the laser module, they usually have a small trimmer potentiometer to adjust the drive, but getting the module out in a non-destructive way may be difficult with some pointer designs.
 

Hymie

Joined Mar 30, 2018
991
If Yaakov’s suggestion of using Ni-MH batteries does not work, I’d consider adding a diode in the battery output. This will reduce the supply voltage by 0.7V which will have the added advantage that the pointer will be drawing a lower current, making the batteries last longer.
Given that the operational current is likely to be less than an amp, I recommend a 1N400X diode.
 
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