Pages: [1]   Go Down
Author Topic: !2 Volt Battery to 7.2 Volt  (Read 1165 times)
0 Members and 1 Guest are viewing this topic.
Houston Area
Offline Offline
Jr. Member
**
Karma: 0
Posts: 68
Arduino rocks
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Good day,

I have a 12 Volt 5 AMP battery which I like to use to power motors that are 7.2 volts.
I was thinking of building my own voltage regulator using
http://www.sparkfun.com/products/527 from Sparkfun. Not sure how to build it so I will have to learn.

Any suggestions on something I can buy that is aready done?
I have been looking but not much success.
Thanks
Logged

0
Offline Offline
Faraday Member
**
Karma: 16
Posts: 2857
ruggedcircuits.com
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Probably not necessary. If you are using a PWM-capable motor driver then you can just drive it with 12V and use PWM (analogWrite()) to set a duty cycle that delivers an effective voltage of 7.2V (or even lower). For example:

Code:
analogWrite(153);

will deliver an effective voltage of 7.2V from 12V.

--
The Gadget Shield: accelerometer, RGB LED, IR transmit/receive, speaker, microphone, light sensor, potentiometer, pushbuttons
Logged

Left Coast, CA (USA)
Offline Offline
Brattain Member
*****
Karma: 361
Posts: 17293
Measurement changes behavior
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Lots of voltage regulators of different types are avalible. First you have to define the maximum current capacity you want the regulator to be able to supply. At higher current levels one really is encouraged to look at switching regulators as the higher efficiencies they have over linear regulators will save a lot of heat problems in your projects.

Quote
I have a 12 Volt 5 AMP battery


I assume you mean a 5 amp/hour rating? A 5 amp/hour battery can supply a lot more then just 5 amps, just for shorter duration.

Lefty
« Last Edit: April 22, 2011, 03:28:13 pm by retrolefty » Logged

Houston Area
Offline Offline
Jr. Member
**
Karma: 0
Posts: 68
Arduino rocks
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Interesting...
I have a motor shield and just contol the voltage using the output. As long as I don't exceed the max value for 7.2.
Yes you are correct 5 amp/hour rating. Lead acid battery which is cheap and use it for testing.
I will add a 3 amp fuse to begin and go from there.
Logged

Pages: [1]   Go Up
Jump to: