what is the connection for ac adaptor in laser ?

4 answers	Answer it!

May 29, 2012. 8:04 AM

mpilchfamily says:

Need more information if you want any help. What laser are you looking at?

May 29, 2012. 8:04 PM

canucksgirl says:

+1

? o_0 ?

May 29, 2012. 2:52 PM

Jack A Lopez says:

I am guessing that you are referring to this instructable:
http://www.instructables.com/id/Protect-Your-Home-with-Laserbeams/
by KipKay.

The laser module used in that 'ible is just one of those ubiquitous (common) red laser pointer modules, and those usually want a constant DC voltage of around 3 or 4 volts DC. That voltage can be supplied by batteries, or an adapter that changes mains power to around 3VDC.

More specifcially, the one Kip says he is using is this one:
http://www.aixiz.com/store/product_info.php/cPath/51/products_id/219/
And that adapter says, in its specs, that it supplies 3.2 VDC.

The actual current used by such a laser will probably be just a few milliamperes. Guessing that number would be approximately the rated power of the laser divided by the supply voltage; since (5 mW)/ (3 V) = 1.67 mA

May 29, 2012. 4:47 PM

Jack A Lopez says:

BTW, I don't know if you were actually planning on building that gizmo, but if you are, please note that the circuit diagram in Step 2 could not possibly work as drawn.

I am guessing the way it is probably intended to work is to have just the wiper on that potentiometer connected to the base of that transistor.

Anyway, there is some discussion in the comments section for that 'ible about how the given circuit could not work, and suggestions for improving it.