|
That's a good idea Blue Raven, you can use this for fwd and reverse. The PWM is running at about 10hz, I wanted to duplicate the manual pressing of the button first before I up'ed the frequency on the circuit. Once I get the second channel going for steering both ways I will stuff around with the frequency to get the best result. The values of the caps and resistors aren't final, if anything I've changed them since drawing the first design.
Your suggestion about using an RC filter is an interesting one, I take it you'd be utilising the charge rate combo of the RC network to "smooth" out the square wave pulses going to the steering coils. I "think" (not sure, anyone is free to correct me) that the coils in the steering arm must have some some of alternating pulse (Possibly simulating a sine wave) going into them to be able to generate a magnetic field (since a DC current won't do this). This field alternates depending on what direction you choose. Left charges one coil, Right charges the other. An RC network might smooth out this "alternating wave" so much as to negate any magnetic field being generated and therefore killing any steering action you might have.
The problem before me at the moment is being able to use just the one potentiometer (variable resistor) to vary both left and right signals. When the pot is centred both channels need to be outputting > 1.2 Volts (this is the quivalent to not pressing either left or right buttons). As the voltage approaches zero the channel is activated. I've found that at the input to the Comparator (U1D) the voltage varies between 0.8 and 1.5 volts. Inverting the other channel is worth a try , I will give it a go and find out if it works. Otherwise I was looking at a "dual-gang" pot where one half is used for left and the other half used for right. The advantage of this is that each variable resistor on the pot is electrically isolated for the other AND i can wire one in the opposite direction of the other. So turning one way increases the resistance of one resistor whilst decreasing the resistance of the other.
*sigh* To many nights out drinking during my uni days when I should of been studying!
|