"Jim Wilkins" wrote in message
...
"DoN. Nichols" wrote in message
...
On 2015-04-06, Ignoramus32423
wrote:
On 2015-04-06, Jim Wilkins wrote:

[ ... ]

If you used an LM317 adjustable regulator for the tracks you
could
tune the voltage for best performance while retaining control,
and
waste less of the battery's energy as heat. You could put a knob
on
the voltage adjustment pot so you have a throttle instead of just
on/off control.

[ ... ]

Jim, you are right. I actually have several LM317T regulators. I
just
wanted to take the easy route. I wish that I could somehow have a
ramp-up of speed, though, not go from zero to full throttle in an
instant.

Hmm ... if using the variable regulators, put a limiting
resistor in series with the control voltage, and an electrolytic
capacitor to slow the ramp-up. (Put a diode in parallel with the
resistor to make the ramp-down faster, however, to make it easier
to
stop before a crash. :-)

Enjoy,
DoN.

The problem is finding a momentary double-throw switch with a
contact that's closed only in the centered position, to discharge
the cap. It could be done with 3-pole switches and relays, or an
extra single-pole switch that acts like a clutch, if he's used to a
manual transmission.

-jsw

The Adjust circuit is a constant current source for the ramp-up, and
the Direction switch provides an instant emergency stop. You only need
a resistor from the top of the cap to the Clutch grounding contact to
keep deceleration within the limit of traction.

-jsw