What component do I need to reduce 9v to 2.4v?

[idiotjohny]

Hi,
Using kipkays idea I want to make a laser that can run on a 9v power source from a Mindstorms NXT so that I can make a robot that can pop balloons.

How would I convert the 9v input to a 2.4v Output?


Thanks in advance,
John

 

[paper183]

It's not that simple, you have to regulate current (amps) too.

 

[idiotjohny]

instead of just saying that can you help me with what i want to find out?

 

[paper183]

You can help yourself by reading the stickies at the top of the page next time http://www.laserpointerforums.com/forums/YaBB.pl?num=1185701612

 

[Gazoo]

instead of just saying that can you help me with what i want to find out?

Read the stickies in this section of the forum at the very top. Start here:

http://www.laserpointerforums.com/forums/YaBB.pl?num=1185701612/0#0

And welcome to the forum..

 

[idiotjohny]

isn't that for 6v?

 

[Gazoo]

That circuit was designed for a minimum of 6 volts. It will take up to as much as 30 volts I believe, and still regulate a diode nicely.

 

[Benm]

It will need cooling at higher voltages though, as it is a linear power source and will convert the excess voltage into heat. At 9 volts / 200 mA it's probably okay for intermittent use, but you should consider a heatsink for continuous operation.

 

[idiotjohny]

that sounds too complicated for me... is there a way to convert 3v from 2AA batteries to 2.4v that is simpler

 

[Benm]

What's complicated? Just build DDL's circuit, or the driver i posted in this section and make sure to keep the LM317 or transistor cool by applying a little heatsink.

Current sources don't care about input voltage, as long as they have a place to dump the heat.

 

[philguy]

Oh crap, that sounds hot!

Think I need to fire up my RCX and get some burning to be done.

I will order 3 senkat-GB-diodes...hopefully if all survive I will have the Predador-Bot with three "lights" in a triangle

 

[styropyro]

that sounds too complicated for me... is there a way to convert 3v from 2AA batteries to 2.4v that is simpler

I really suggest building the curcuit in the links members gave to you, but if you want 2.4v from batteries just use rechargables, 2 AA rechargeables will put out 2.4v

 

[Archane]

You could use 4 AA batteries but you will fly through batteries, 2 CR123's work the best since they can be recharged and take up alot less space thant 4 AA's.

 

[Gazoo]

4 AA batteries will really not work well with Daedal's circuit..even 4 E2 lithiums would be questionable, as would 2 CR123's.

As you suggest, 2 RCR123's are a decent choice. Since they are rechargeable, the voltage for 2 RCR123's will be 8.4 volts off of the charger, and quickly drop to a comfortable 7.5 volts, and slowly discharge from there.