Page 2 of 2

Posted: Mon Jul 27, 2009 9:35 am
by timpootle
You won't hear much from Simon, I fear.

SimonR wrote:I've de-camped to the DIY electric car forum where the same posts have received a much more encouraging response. Here is the thread about the mechanical speed controller:


Posted: Mon Jul 27, 2009 1:56 pm
by Night Train
Ahhh yes, thanks Timpootle.

I got a pm from Simon to this effect yesterday on another forum we both use.

So, has anyone tried making and using one of these for a vehicle yet?

Speed controller design?

Posted: Sun Sep 20, 2009 6:37 pm
by hat27533
Continuing on from the mechanical speed controller, have we missed a trick in the original design?

Surely if an old motor com was used to switch current through to the drive motor, all we would need to do is control the small motor speed driving the shaft with an affordable speed control solution thus amplifying the effect?

you would not need the complicated cone shape com and sliders?

Obviously there would need to be some fail safe control in there too, thats not difficult either.

Posted: Sun Sep 20, 2009 11:14 pm
by Night Train
All that would do is to vary the frequency of the pulses and not the width of the pulse.

The motor speed is controlled by varying the width of the 'on' pulse relative to the 'off' pulse at a high frequency. The longer it is on the faster the motor will go as it 'sees' a higher mean voltage.

If you just vary the frequency with straight com bars driven by a small motor then the motor will 'see' the same voltage at a varying frequency which will not do much to vary the speed.

Here's one I made earlier from scraps and off cuts.