The Main throttle VR1 is fed
by two variable resistors VR3 and VR4. VR4 sets the Minimum
speed of your throttle control while VR3 allows you to set your
C2 filters the control of
your circuit but your supply to the track is unfiltered and
maximises your motor performance. The Minimum speed provides a
"bleed" of power to the inertia capacitor so your
starting is fairly instantaneous. You should get a very good
pulsing effect but ensure that you have capacitor C3 in place
or you may be disappointed in the output
When your throttle is turned
off, your inertia capacitor will take over and start
discharging through the base of TR1 and the brake VR2.
The "Braking effort"/
coasting distance can be increased/decreased by turning VR2 and
bringing the train to a stop earlier.
Some people I know substitute
a Resistor for VR2 and a push button which could lead to
an infinite slowdown time for the train... that is your choice!
Adjusting your throttle
When first setting your
throttle, turn your inertia switch (S1) OFF. Move your main
throttle from its minimum speed setting about 60 degrees (I
prefer to refer to it as 2 o'clock as I start with it in the 12
o'clock position) then adjust VR4 so that your light engine
will just begin to move.
Then set your throttle to its
maximum speed and use VR3 to set your throttles maximum speed
or the desired maximum speed for your layout. This will enable
you to use most of your throttle to control your train speed
and provide a bit of insurance against those who want to run a
train like a slot car! This is especially handy if you have a
switching layout and want refined control