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We need more power Scotty — Parallax Forums

We need more power Scotty

MarkCrCoMarkCrCo Posts: 89
edited 2014-09-25 17:33 in General Discussion
"I'm givin it all she's got Captain"

My robot is doing a great job of sweeping the floors now but.. He doesn't have enough power to finish the job. With brand new batteries (4 AAA) he runs great. He only has a 3 inch brush to clean with so it takes multiple passes around to get the whole room. As the batteries fade he starts doing resets when he has to turn around. Turning around requires him to back up away from the obstacle (usually a wall) and turn until he can find a clear path. I'm sure it is the servos having to restart in a new direction with older batteries that is causing the issue. I tried the suggestion of running a "large" capacitor across the servo power wires but I'm using the BOE with the servos in the separate connections and not on the bread board. My bread board is full so moving them over there isn't an option. I crammed the leads of the capacitors into the wiring harness. I'm not sure if they are making a good connection that way. My guess at what would be a large capacitor was 1.0 uf. Anyone have any suggestions on batteries that would last longer or how I can make the ones I'm using not fade as quickly?

http://youtu.be/YkEaQaBjjkQ

Comments

  • Martin_HMartin_H Posts: 4,051
    edited 2014-09-13 08:52
    A capacitor helps to handle spikes in power consumption, but the Board of Education includes some decent capacitors that usually do the job. To me it sounds like you might consider a battery pack with more total power. The Parallax Li-ion http://www.parallax.com/product/28988 pack, five AA cell http://www.parallax.com/product/753-00007 pack, or Boe boost http://www.parallax.com/product/30078. All of them increase the total amount of power available before a brown out occurs.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2014-09-13 09:08
    That's a fantastic robot. I like it.

    If you're going to build robots, you want rechargeable batteries.

    I have one of Parallax's Li-Ion packs with is great but I tend you use LiPo packs made for RC vehicles in most of my robots. LiPo packs aren't too expensive if you get them online from HobbyKing.
  • Hal AlbachHal Albach Posts: 747
    edited 2014-09-13 09:17
    http://www.parallax.com/product/28989 is selling for the same price as http://www.parallax.com/product/28988 and includes the batteries. You may also want to look at Hobby King site, they have battery packs and chargers up the wazoo. It also looks like a little extra weight over the BOE-BOT main wheels will help reduce the loss of traction when trying to turn.
  • MarkCrCoMarkCrCo Posts: 89
    edited 2014-09-25 17:33
    Great ideas!!! He is now running on rechargeables and lasts over an hour. Plenty of time to have another set recharged and ready and no more brown outs. I added an ounce of weight over each wheel and his traction is much better. I think he still might be able to double that and improve even more.
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