go_away

Author Topic: 7.2 volt battery  (Read 3042 times)

0 Members and 1 Guest are viewing this topic.

Offline TrumpkinTopic starter

  • Supreme Robot
  • *****
  • Posts: 1,177
  • Helpful? 5
7.2 volt battery
« on: January 19, 2008, 11:34:24 AM »
I was wondering if the $50 robot microcontroller can run  on a 7.2 volt battery pack.
Robots are awesome!

Offline rgcustodio

  • Robot Overlord
  • ****
  • Posts: 217
  • Helpful? 0
  • Use "Search" and ye might find answers!
Re: 7.2 volt battery
« Reply #1 on: January 19, 2008, 11:51:32 AM »
the robot should be able to handle a 7.2 battery pack:
http://www.societyofrobots.com/schematics_powerregulation.shtml

the part used, KA7805ETU-ND, can handle a max Vin (input voltage) of 35VDC according to the data sheet (Absolute Maximum Ratings on page 2):
http://www.fairchildsemi.com/ds/KA/KA7805E.pdf
The best thing one can do when it's raining is to let it rain. - H. W. Longfellow

understanding is the path to enlightenment

Offline TrumpkinTopic starter

  • Supreme Robot
  • *****
  • Posts: 1,177
  • Helpful? 5
Re: 7.2 volt battery
« Reply #2 on: January 19, 2008, 02:18:18 PM »
thx!
Robots are awesome!

Offline Admin

  • Administrator
  • Supreme Robot
  • *****
  • Posts: 11,653
  • Helpful? 169
    • Society of Robots
Re: 7.2 volt battery
« Reply #3 on: January 25, 2008, 07:58:42 PM »
servos cannot handle 7.2V, but the microcontroller with the 5V regulator can.

Offline SkinnyDog

  • Jr. Member
  • **
  • Posts: 10
  • Helpful? 0
Re: 7.2 volt battery
« Reply #4 on: January 27, 2008, 11:24:55 AM »
Hi guys

 Newbe here, i think i also went a bit over kill when i ordered my battery got a 7.2v 3000mah only realised the size when i got it, the connector plug?male pins is a lot bigger(thicker gauge wire) will have to down size it through the on/off switch.

This will work?

Electronics is foreign to me as i studied Mechanical Eng. im ok putting it all together if shown how but the calculations and terms are a bit of o struggle, i did manage to get my solar engine to work from my gunk bot book, it did take some time though.

Offline gamefreak

  • Supreme Robot
  • *****
  • Posts: 543
  • Helpful? 2
  • Robo-Enthusiast
Re: 7.2 volt battery
« Reply #5 on: January 27, 2008, 11:30:35 AM »
the gauge is generally for the amount of current being drawn, more current lower gauge, thicker wire

Quote
(thicker gauge wire)
lower gauge is thicker, dont ask me why. so as long as you dont have the full 3 amps, you should be fine but if your thinner wires start smoking/melting/exploding then you may have a problem :P
All hail Rodney, the holy 555 timer
And Steve said: "Let there be lead!"

Offline frank26080115

  • Supreme Robot
  • *****
  • Posts: 322
  • Helpful? 2
Re: 7.2 volt battery
« Reply #6 on: January 27, 2008, 11:50:52 AM »
servos cannot handle 7.2V, but the microcontroller with the 5V regulator can.

Servos can, and my servos haven't failed yet

Offline SmAsH

  • Supreme Robot
  • *****
  • Posts: 3,959
  • Helpful? 75
  • SoR's Locale Electronics Nut.
Re: 7.2 volt battery
« Reply #7 on: January 27, 2008, 03:19:09 PM »
yea i usually use 9V or 6V motors and then a 7.2V pack. it usually works for me :)

~smash
Howdy

Offline ed1380

  • Supreme Robot
  • *****
  • Posts: 1,478
  • Helpful? 3
Re: 7.2 volt battery
« Reply #8 on: January 27, 2008, 04:06:59 PM »
remember motors dont have electronics inside and they're ok with overvoltage, but servos arent
Problems making the $50 robot circuit board?
click here. http://www.societyofrobots.com/robotforum/index.php?topic=3292.msg25198#msg25198

Offline TrumpkinTopic starter

  • Supreme Robot
  • *****
  • Posts: 1,177
  • Helpful? 5
Re: 7.2 volt battery
« Reply #9 on: January 27, 2008, 07:52:49 PM »
yeah so basically i probably don't want to usea 7.2 volt battery with the $50 robot microcontroller. Just wondering cause I was planning on making a $50 robot microcontroller for some1 else and I had a 7.2 volt battery on hand. Couldn't I put a couple of diodes between the battery and microcontroller to reduce the voltage to 6v?
Robots are awesome!

Offline ed1380

  • Supreme Robot
  • *****
  • Posts: 1,478
  • Helpful? 3
Re: 7.2 volt battery
« Reply #10 on: January 27, 2008, 07:58:38 PM »
you mean resistors, right? cause diodes wont help.

resistors would turn that extra enery into heat. same thing the regular 5v regulator does. get a switching regulator
Problems making the $50 robot circuit board?
click here. http://www.societyofrobots.com/robotforum/index.php?topic=3292.msg25198#msg25198

Offline Admin

  • Administrator
  • Supreme Robot
  • *****
  • Posts: 11,653
  • Helpful? 169
    • Society of Robots
Re: 7.2 volt battery
« Reply #11 on: January 27, 2008, 08:00:11 PM »
Quote
Couldn't I put a couple of diodes between the battery and microcontroller to reduce the voltage to 6v?
I think it will work . . . check the diode datasheet to make sure it can handle your required voltage/current/power requirements.

Offline TrumpkinTopic starter

  • Supreme Robot
  • *****
  • Posts: 1,177
  • Helpful? 5
Re: 7.2 volt battery
« Reply #12 on: January 27, 2008, 08:01:50 PM »
Ok, i'll try that, thx!
Robots are awesome!

Offline airman00

  • Contest Winner
  • Supreme Robot
  • ****
  • Posts: 3,653
  • Helpful? 21
  • narobo.com
Re: 7.2 volt battery
« Reply #13 on: January 27, 2008, 08:19:35 PM »
you mean resistors, right? cause diodes wont help.

resistors would turn that extra enery into heat. same thing the regular 5v regulator does. get a switching regulator

true , but diodes have a voltage drop of about 1 V
Check out the Roboduino, Arduino-compatible board!


Link: http://curiousinventor.com/kits/roboduino

www.Narobo.com

 


Get Your Ad Here