Problems With Old Futaba Parts

I have been spending the majority of my spare time recently trying to finish up the flash + Red5 + PWM(pulse width modulation) board control of the RC car that I demonstrated on the projects page. Starting a new job and moving to a new state stalled progress for a month or so. About five minutes from a fully working demo, my pwm board started smoking for the second time. It seems that the old Futaba MC112B ESC(electronic speed control) that I am using is just too old for this design. The Futaba MC112B controller is a very advanced design for 1985, but in 2008; it should not be behaving as it is. What happens is when you hook up the massive 7.4v multiple cell RC car battery, the Futaba ESC exerts all of the battery's potential onto the PWM board at the PWM motor hook up. When I experienced arcing on the motor pins while testing, I figured it was just due to a loose connection. However, after experiencing a near fried board for the second time, I am certain that the Futaba ESC is to blame. Furthering my opinion, is that I have also seen the ESC cause strange behavior on the stock Futaba RC receiver that I replaced with my pwm board.

I disassembled the Futaba ESC to discover that it looks like a massive H-bridge is being used for the majority of the work. When I started learning about electronics I really got by easy in not having to understand all of the types of transistors. I'm shifting my focus primarily towards the MOSFET and am determined to know the in's and out's of every type of transistor before proceeding. In my only EE class I had in college, our team lost a competition because I didn't fully understand the types of transistors I was using, so ill be damned if I'm going to skate over it now. It will probably be a month or so before I have anything else interesting to demonstrate. I hope you had fun wading through all of the confusing acronyms of this post.