Just having a quick look around slot car accessory sales and
the old system of a rheostat is still the most common speed
control. PWM seems to be regarded as new and innovative.
These controllers are significantly more expensive than rheostats
yet would be a simple project. Maybe there's some $$$ in this
for you doing controller conversions ???

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http://www.hoslotcarracing.com/Controllers.html

Turbo EC Basic Controller

The newest product in the Parma hand controller line is the Turbo EC
Electronic Controller. This model incorporates true solid state high
frequency pulse width modulation (PWM) to provide precise control
of any slot car motor from H.O. to 1:24 scale.

Unlike many so-called electronic hand controls that simply use diodes
to replace the power resistor, the Parma Turbo EC control automatically
adjusts to the motor itself.

This new generation of hand controls entirely does away with the
impedance ratings standard hands controls employing a resistor
require. One control can now be used to control any slot car motor
regardless of it level of tune or size.

The Turbo EC includes an integral fuse for protection and an on/off
switch for dynamic motor braking

Price: $70.00

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