How to power a laser pen (very easy question)

[vlor]

How to power a laser pen? (very easy question)

I have a laser pen. It takes two 1.5V AAA batteries.

Can I use this adapter, cut the wire on the end, and solder BOTH of the wires onto the spring?

**broken link removed**

 

[betwixt]

No ! That would just damage the adapter.

It looks like that pen takes two coin cells, not pen cells. If it's coin cells, connect the negative (-) wire to the spring and the positive (+) wire to the brass screw thread.
If it really is pen cells, as shown in the photo, check how the cells fit into the body of the laser, one side will go to the spring and the other will connect to the body. You should match the polarity with the adapter wires.

Brian.

 

[vlor]

Ahh okay, got it.

What about a maglite flashlight?

Usually a DC illustration show the electrons flowing through a wire out the - end of the battery, into the light bulb, and then into the + end of the battery. Like this:

With a Maglite however, there is just a spring touching the - end of the battery, and not connected to anything else... why is this?

This is what my Maglite looks like:
**broken link removed**

Another illustration is on the maglite website: Spare Parts > Anatomy > Mag Instrument, Inc. - Manufacturer of the Maglite® Flashlight

Where are the electronics going? Are the electrons traveling through the actual metal casing of the flashlight where my hands are touching?

Thanks

 

[KJ6EAD]

Current flows through the metal housing for the (-) battery connection. On your laser, the battery contact spring has some corrosion on it from a battery leak. You'll need to clean that before attaching your power source.

 

[pranam77]

If your laser pen is not designed for AA or AAA cells, and uses button cell at present, the excess current from the AA or AAA battery may damage the laser diode. Cross check wither the pen is having a inbuilt driver for the diode.
Cheers