Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

How to Register on LPF | LPF Donations

9V to 5V

RA_pierce

RA_pierce

0
Joined
Sep 16, 2007
Messages
3,667
Points
113
I have a small problem here...
I am trying to put together a battery powered mini labby.
The laser module is already complete, it just needs power and heatsinking.
The module I'm using needs 5V... but I want to run it off a 9V.
So I want to drop the voltage down... Could I just hook up a few diodes in series with the battery?
I would like to keep this simple because I dropped my soldering iron and it doesn't work too well  :-/.
Any suggestions?

My knowledge of electronics is pretty basic... I'm still learning.

Thanks in advance for any help!
 





I don't know if adding so many diodes isn't gonna totally screw with your battery life.I mean, they're gonna turn some of that current into heat.

Well, theoretically it should work but it isn't gonna be efficient.
Or you could use a voltage divider. :-/Then again my knowledge is also limited.I bet someone else is going to come up with a better answer. :-/
 
A 7805-regulator should be good.

7805datasheet.gif
 
A 7805 is a 5 volt positive voltage regulator.  Unlike the LM 317 which is adjustable, the 7805 is fixed output.  It is normally found in a TO220 package although if you only need 100 mA or less, The 78L05 in a TO92 case is small.

Mike
 
Like everybody else said, the 7805 is great. It is super easy to use, here is a quick diagram on how to use it for your application:
 

Attachments

  • 78051.GIF
    78051.GIF
    7.9 KB · Views: 13,257
Ok so change of plans, I'm going to just use 4 AAA NiMH batteries (fully charged they output ~5V). But thanks for the suggestions anyway...

However...
I did find a phone charger.
Supposedly the output is 5V 1A.
Could I modify it to output less current? Or could I hook up my laser to it as is?
It would be pretty neat if it could operate on batteries and a little phone charger.
 
If it really is regulated and puts out 5v, then you don't need to modify it at all because the driver on the laser will limit the amount of current going through.
 
i made one and i used to cr123 batterie holders and mounted thim on the top of a labby heatsink and hooked a toggle switch to it works nice
 
styropyro said:
If it really is regulated and puts out 5v, then you don't need to modify it at all because the driver on the laser will limit the amount of current going through.
Click to expand...

This is good, yes?
I'm more worried that I'll burn up the driver.
1A won't be too much for it over a few minutes?
DSC07267.jpg
 
With that wide input range, it must be a switcher and regulated. Test it first with a dummy load.
Just because it says 1 Amp doesn't mean your circuit will draw 1 Amp. That depends on the load impedance.

Mike
 
You must log in or register to reply here.


Back
Top