Peter Gee wrote:
>
> Hi
> I am thinking of designing an electronic speed controller for a remote control
 car using a PIC.  I have a number of ideas at the moment, but my favourite is
 to use the microchip application notes for creating a pwm (an654) with the
 16f84, then convert the incoming pulse into a pwm stream.
>> Any hints at all, from choice of mosfets, noise considerations, to
 programming tips would be greatly appreciated.
>
> Regards,
>
> Pete

I work on the same project now , so maybe we can help each other

1 I plan to use a 12c508 because the pwm doesn't have to be too
accurate , it's cheap , I have a bunch of it in the box

2 the first step of the project is to measure the min/max
pulse width transmitted by the receiver

3 simulate it with a stamp - for easy testing

4 find the data sheets for the part IRL2203

(I opened a competition speed control and 6 of these makes the
drive)

the unit was rated at 40 amps (I don't think it's true , but who
cares - I want to make a unit just as tuff as the pro-one)

if I could know the exact data of the IRL I could seach for a
H bridge of the same rating :)

5 make the lookup table for the drive
        1 forward at the desired pwm rate
        2 neutral (free run - lever at neutral position)
        3 brakes  on (short circuit the motor inputs)
        4 reverse (just as the forward option)

that's all

bye
charley