Power recomendations
w4fej
Posts: 264
I'm building a remote control system for a rather large R/C tug boat. I am putting the control unit in a enclosure that is about the size of a large handheld calculator. I have already resigned myself to having the battery exterrnal to the unit as there isn't much room left. I MAY be open to the idea of even a belt mounted battery pack with a tether. My druthers would be something attached to the bottom of the handheld unit.
The unit contains the 40 pin Prop, the 60mw Xbee Pro with wire antenna and the Parallax 2 X 16, backlit LCD display and 6 LED's for indicators. I'm using a 5.0VDC LDO voltage regulator driving a 3.3vdc regulator.
Would something like 3 or 4 9vdc batteries have enough capacity to operate the unit for a couple hours?? I'd like to use a Li-Po battery but I'm put off by the cost of the chargers for them..
What do you think would be a good way to go??
Mike B.
The unit contains the 40 pin Prop, the 60mw Xbee Pro with wire antenna and the Parallax 2 X 16, backlit LCD display and 6 LED's for indicators. I'm using a 5.0VDC LDO voltage regulator driving a 3.3vdc regulator.
Would something like 3 or 4 9vdc batteries have enough capacity to operate the unit for a couple hours?? I'd like to use a Li-Po battery but I'm put off by the cost of the chargers for them..
What do you think would be a good way to go??
Mike B.
Comments
1) 9V batteries have TERRIBLE energy density. Don't use them unless you need an easy 9V. Look into protected LiPo's, protected LiIon, or NiMH.
2) Reduce power consumption whenever possible. Put things into standby mode. Etc.
3) Run the propeller at as low a frequency as your application can stand. Use as few cogs as you can stand. More MIPs = more energy drain
4) Don't use LDO regulators. They turn your voltage drops into heat. Heat = wasted energy. Use a switching power supply if you can.
5) Turn off your LCD when it's not in use. Maybe have a button press or something 'wake' it up.
6) If your tug boat is electric motor powered, make sure to use an efficient motor and efficient speed controller.
Sounds like a fun project!
Oh, and make sure to add some silica to your project box so that humidity won't mess up your electronics.
the anyvolt micro is a Wonderfull device ! .
Or if you are bold a gutted 12V car charger has in it a easy to hack switcher..
Make sure you check to see if adding a switching regulator causes interference with any wireless devices you're using.
@Mike, If you're into RC stuff, LiPos are really the way to go. While I usually charge my LoPos with a relatively nice charger, I also use this inexpensive charger for some of my 2S and 3S packs. It seems to get the job done, just not as fast. The cheap charger charges at around 600mA so it can takes a while for it to charge a large capacity pack. You also wouldn't want to use it on a pack with very low capacity.
Duane,
Did you do your own PCB with that switcher...or use a professional PCB? I know switchers can cause a lot of noise if the layout isn't perfect.
This is the regulator that caused be some trouble. I think it's ironic that one of the "Customer Projects" listed is using the regulator in a Spektrum RC radio. When I used the regular with a Spektrum radio the TX and RX had a hard time establishing a lock with each other. This same regulator also interfered with my GPS module.