[VAC] Re: Tekonsha Brake Controllers

["Carol and Oliver Filippi" <ofilippi@xxxxxxxxxxxxx>]

Polly,

You have an excellent handle on the laws of pjhysics.

The pendulum (inertia) type controllers will work best with a light trailer
relative to the tow vehicle's weight.

The tow vehicle HAS to slow down for the pendulum to actuate the brakes on
the trailer.  If the tow vehicle's brakes are not strong enough to slow the
entire rig (tow vehicle and trailer) there will be no pendulum or inertia
action by the brake controller - hence no trailer braking.  However, once
the trailer brakes actuate, the whole rig starts to slow down and the
pendulum swings faster and further, hence one goes from no brakes to a lot
of brakes!

This does not sound like the greatest design idea.  [Which explains the
problems noted on this forum.]

The ONLY way such a system COULD WORK WELL is if there is some fore and aft
slack between the tow vehicle and the trailer.  Then the tow vehicle could
slow down without having to slow  down the trailer too; at which point the
controller could actuate the trailer's brakes in proportion to the
decelleration rate of the tow vehicle.

To get fore and aft slack with a weight distributing hitch would be a
masterpiece of Mickey Mouse Engineering.

The only logical solution is to actuate the trailer brakes based on the
action of the tow vehicle's driver - which means sensing the brake activity
of the tow vehicle.

Hence tapping off the ABS controller of the tow vehicle is the only method
that makes sense.

At this point, one could develop an antilock brake system for the entire rig
if there were sensors on the trailer wheels.

Oliver Filippi