Wookong voltage issue

[Kilby]

Anyone else find a problem with their Wookong not stepping the voltage down that is sent to the RC receiver? Earlier this year, when I hooked up a 4S battery for the first time, both of my gimbal servos fried instantly. I needed a BEC anyway, so I put one in place and all was well again. Then, just recently, I picked up an NEX and gentLED trigger from a fellow board member. When I plugged the trigger in, it wasn't working. I just assumed that I had damaged it in transit or something and ordered another one. It arrived today and upon plugging it in and powering up the craft, the famous smoke monster appeared in my workshop. I plugged a servo extension cable in and checked the voltage and it was just shy of 15 volts (it was a spent pack on the craft).

The real crappy part about it is that I had that trigger sent here rush delivery for something I need to shoot this weekend. I spent just as much for shipping as the price of the actually unit itself, and I STILL don't have a working trigger.

Anyone else seen this problem?

 

[shsober]

If you can get both triggers working, I'll buy the spare. BTW, fall colors have peaked in much of West Virginia but look good here. I'll be up on Skyline Drive on Monday and may spend a night or two up there next week.

 

[RTRyder]

I haven't run into it personally but plenty of other people have, the problem is usually a bad PMU. Interesting that it didn't fry the RX as well, or did it? Running gimbal servo power through flight controller boards is a bad idea regardless of which system you use. Many digital servos are capable of pulling 3 to 4 amps at max current draw so if both are under load there can be as much as 6 to 8 amps flowing through the regulator circuit on the flight controller and very few if any are designed to handle that much current. In the case of MK controllers the Recomm regulator used in the servo power circuit is rated at 1 amp!

Best practice is to always use a separatec BEC to power the gimbal servos and connect only the signal wire to the flight controller, on my CS6 I use a CC BEC Pro which has two output leads, one powers the WKM, the other powers the Skyline RSGS/servos on the AV130.

Ken