need help with r/c model electronic speed control

[raimain]

hi im new to this forum and in bad need of help.

i am wanting to make a esc for use with my model tank that im working on, but am unsure where to start.

i was thinking that it would need;

2 motor outputs that can provide upto 7.2v @ upto 12amp.
2 inputs that collect the pwm info from the reciever.

im not sure which chip would be best to use and i dont really know much about the writeing of the code for the chip, but i do have a programmer to use to program the chip.

i hope that someone can help

thanks

raimian

[sayzer]

PIC16F690 could be a good choice to drive two motors in both directions.

Check its data sheet first, have some idea and come back here again


---------------------

[Acetronics2]

Hi, RainMan

In my drawers, I have a Twin Esc for big boats ...

Throttle drives the two motors ... AND Ailerons drive the Left/right motors differential.

I know tanks have two Throttle levers ... but driving is much easier that Way !!!

Hardware will be a little "heavy" for your purpose ( 50 continuous Amps, 3000 Hz, relay reversing, and Fiber Optics coupling to power units ), but soft may be greatly re-usable.

A little notice ... listing is 1400 Basic lines ( but with the blank lines !!! ... so, let's say 700-800 PbP program lines ...)

For info, to be comfortable, you need Two Processors w/PWM ( twin sticks driving ??? ), OR one with 2 PWM outputs.

I used a 16F876 ... but less than half memory is necessary !!!

Alain

[raimain]

i was thinking 1 chip would be better so it can do (channel mixing) to mix the throttel and the steering.

the motors that im using are standard 540 motors and standard 7.2v r/c batteries.

i had a look around and there is 1 esc in a microchip app note but its for a r/c plane so it has no reverse(AN847), but will probly be usefull for getting the code for reading the pwm from the reciever from.

i also have a load of TIP120 NPN darlington transistors to use, but not sure if they are the right sort for this project.

i hope that someone can help me with this project

[Dave]

raimain, I thought you might need some assistance so here is a circuit I came up with about 8 or so yeard ago to drive a BARBIE Hotwheels car for my daughter. The circuit as built can supply 300 amps surge and as built has no heat sinks at all. All you need is 1 pwm output and a direction bit. HTH

Dave Purola,
N8NTA

[raimain]

thanks for the circuit diagram, now i just have to build it.

does anyone know which chip would be best for this and how do i find the code that will work propely for this project.

thanks again

raimian