HobbyKing 70A ESC 4A UBEC

 ind3nt 12 points

For simple terms, A 'BEC' (Battery Eliminator Circuit takes power from your battery directly to your receiver and servos. This is all inbuilt into your ESC so you dont have to buy one externally. For this product, you could power 6-8 9gram servos without putting stress on the ESC. Reasons why I use a BEC is because I always like have a failsafe so I know that if my ESC burns out, I will still have control of my control surfaces. Also it makes everything run a lot cooler.

 greasmnky 163 points

There has to be, no way to control it otherwise. Even the ones without the internal bec have a servo lead. I see what you mean looking at the picture, though. It looks like it doesn't have one. I have many of these in the 60 Amp version and they are fine trouble free units. I highly recommend buying the programming card. Well worth the money.

 Christer 2 points

I did guess that there for sure was a servolead but I didnt risk it. lol. Bought the 50A one instead. Will use it on my h-king edge 540T. Did also buy the programming card :)

 Tank1 270 points

If you look very closely you can just see the servo lead as you call it hiding behind the live/red wire,as you already know there wouldn't be no point in having an ESC with out that wire. :-)

 greasmnky 163 points

Spare yourself the trouble and the endless beeping, buy the programming card. It is the round one shown above for 6 bucks. If you can't wait, try one of the other esc's files, like the 60 amp one of the same type. It should be the same.

 Tank1 270 points

To be honest there isn't much between them both in way of which is better,but i'd tend to go with this one as it has more Amps but having said that i find the plus series of ESC's to be bullet proof,but that doesn't mean these are not because i've had no trouble with them,i'm now about to buy some more as the 60amp plush are out of stock. *-)

 Irfan 10 points

I finally bought the Plush 60A and 30A. They are awesome but they don't have governor mode and that's a must have for heli. So I ordered YEP 60A. Still waiting to receive them though. Anyways thanks for your reply.

 Jonas 3 points

solved...was the throttle trim

 scottc 100 points

what is pwm?????

 sorenlaf 92 points

Pulse Width Modulation. A brushless motor is, essentially, a 3 phase motor operate on square waves instead of sine waves. Here comes the speculative part. I THINK the pwm frequency is how fast the ESC switches as it build up the square wave that drives the motor. The drive signal to the motor consists of three waves 120 degrees out of phase. The shape of the wave depends on both the throttle position and the pwm frequency. My GUESS is that higher rpm/kv motors require higher pwm frequencies. Sorry I can't give you a more detailed explanation.

 foamie 13 points

Close but PWM creates a sine wave similar to ac by switching the dc at varying pulse widths to increase the average voltage and then decrease it again so that the average voltage forms a sine wave simialar to ac. Difficult to explain without diagrams but check wikipedia for good basic diagram and explanation