First Build: Cant get the FCB to power up

[toad81]

Hi all,
This is my first post and my first build...almost complete. Here is a rundown of my setup:

• Frame: 650mm
  
• FCB: Multiwii 328p w/ FTDI & DSM2 Compatible
• ESCs: Turnigy Multistar 30 Amp Multi-rotor Brushless ESC 2-4S (OPTO)
  
• Motors: NTM Prop Drive Series 28-26A 1200kv / 286w
• Battery: Turnigy 3000mAh 4S 30C Lipo Pack
• Transmitter: Turnigy 9x 2.4GHz 9ch
  
• Receiver: Turnigy 9x 8ch v2 2.4GHz

I have everything put together, but I'm struggling with getting power to the FCB. I know that this should come from the ESC's. When I plug in my Lipo, the LED's on the board don't light up and the LED indicator on my receiver does not light up either. If I connect a receiver battery pack (5.5v) to the receiver it lights up, as well as the LED's on the FCB.

I have traced the power from the lipo through the power distribution board to the ESC's, but when I check the connector going to the board from the ESC with the multimeter, it jumps around (not sure if it's the right way to check it anyway).

I did hook the receiver battery pack up to to the receiver and was able to bind it to the transmitter, but that's as far as I got.

Another thing I tried is to plug the ESC's into the throttle channel of the receiver to see if I could get the motors to spin up with no luck.

Can anyone point me in the direction of more information/documentation on how all of this should work? Thanks!

 

[GJH105775]

The problem is that you don't have a BEC (Battery eliminator circuit). Most of the time they are built into the ESCs, but your ESCs are (OPTO), which means they have no BECs.

Here are two options, option one, and option two. You only need to buy one, and the cheaper one seems to have better reviews.

 

[toad81]

Thank you for pointing that out! I went down that avenue myself previously, but somehow convinced myself that the ESC's had switched BEC. In checking again, you are absolutely right!

 

[holtneil]

Hi toad81 go for the switching bec that George left the link to (option two) I have used these and are very good , the switching becs work cooler than the non switching type , you must check what voltage range the FCB etc runs on but 99.9% of the time this bec will be ok