onsdag den 1. januar 2014

Powering your system with a UBEC

I use a UBEC to power the MultiWii pro, my two servos on the gimal and the reciever. I ordered two switchable UBECs off Ebay for $5, i am going to use the one UBEC to power the flight controller and the other to control the two gimbals on a separate battery.

There are different types of UBECS available but this one can be used and regulated between 5v and 6v and can be used with 2s up to 6s lipos. converts from 5.5volts to 26 volts into a constant voltage of either 5volts or 6 volts depending on the jumper setting. You could off coarse use your ESC to power your board, (if yours are still working in contrast to mine) but there is a chance that using the ESC´s you might draw too much power, making your multi-rotor fall out the sky if the flight controller powers off. Have  a look at this video that explains how a BEC works http://www.youtube.com/watch?v=hgXP4__GjSo

Firstly i found that most lipo batteries come with differnt connectors, JST, Dean, EC3, EC5, XT60 connectors and its quite a hassle converting from one to the other, i myself started using XT60 connectors and i bought a stack of XT60 connectors from China through Ebay they are pretty cheap and you will be amazed how often you need to use on of these connectors. I am no expert on lipo batteries but check out this guys page http://www.rchelicopterfun.com/rc-lipo-batteries.html he will tell you what there is to know on Lipos, chargers and the works. Read the safety precations on using lipo´s almost at the end of his article. he explains how not to puff your battery, but also what could happen if you are not cautious,.

Anyway i converted all my batteries with XT60 connectors, You can of coarse buy converters, they will convert from one to the other in a jiffy, but i am a true DIY man, so soldering is the thing i prefer to try and end up fucking it all up in due process. when soldering the connectors on and off take care not to short your battery in anyway, otherwise, puff and the thing grows to 4 times its size, gives you some awful smelling smoke and a fucked up battery (tried that too), lucky for me the thing never caught fire. So if you are newbie like me take great care and as i mentioned earlier read the advice posted in the link above.
What i initially learnt was to solder one cable at a time, cut the red, solder and then heatshrink it before moving on to the next wire, this way the chances of shorting are minimal.

I grabbed the UBEC and soldered a XT60 connector on the OUTPUT wire, remember to get the polarity right, red on +, black on - otherwise puff, another fucked up battery.

I cut  off the connector and striped the wire, found two red and two black wires

 Soldered the extra set of red wires together.
 soldered the two blacks together
Soldered the black/negative cable with the black/negative from the UBEC and the red/positive with the red/positive wire.
 Should look a bit like this, but with better soldering skills.
 Mounted the connector i had cut off again , had to find an extra connector to mount on the other cable.

 I have run out of heatshrink, this does a much neater job than duct tape, but this will do for now, notice that i now have two connectors available each giving five volts, you could make additional connectors if needed, i only need two, one for my reciever and one for the MWII flightcontroller.

 I connected the one connector into the Orange DSM2 through the BATT/BIND port, the middle rail has to be red/+ and the bottom black/- leaving the top signal rail empty.
On the last connector i took one of the signal wires from any of the 4 ESC´s and plugged it in to the empty slot next to the red/+ wire

Plugged the connector into the MultiWii pro board, in my case i used D5 which is motor 3, the red and black provide power to the MultiWii board and the green is the signal cable to the ESC from the MultiWii Pro board. Remember the inner rail is signal, middle is + and bottom is - on the Hobbyking MultiWii pro board.