Re: New Video: Tatra PCC Controller Overhaul and much more. Leipzig Germany 1991. 21 minutes.
  Dudley Horscroft

Thank you Richard. A most enlightening view of the maintenance of a Westinghouse Controller. Given that while the nominal voltage
may be 600, I believe that voltage during braking could be up to 800. Although there are 99 contacts, those past 83 are I think for
field weakening, while 1 and 2 are specially heavy to reduce jerk. This leaves 80 contacts to get from about 1 volt to 80, so a
maximum of 10 volts difference between adjacent pairs. Say contacts 2 and 4 are depressed on one side, and 3 and 5 the other. 3
and 5 complete the circuit, when 2 and 4 are depressed - the rotor arm does not carry any current. Then when the arm moves one
notch, so that 4 and 6 are depressed instead of 2 and 4, the change is an addition of either 10 or 20 volts - have not quite figured
it out in my mind. Hence the unnoticeable change in power to the motors.

I presume there had been something badly wrong with 501, else she would not have been scrapped. But the bogies appear to be
excellent condition - useful spares for someone who wants to extend a tram and needs PCC bogies. Ordinary resilient wheels, so B2

A worthwhile 21 minutes. Thank you.


Dudley Horscroft
----- Original Message -----
From: "Richard Youltressteleg@... [TramsDownUnder]" TramsDownUnder@...>
To: TramsDownUnder@...>
Sent: Thursday, August 10, 2017 10:47 PM
Subject: [TramsDownUnder] New Video: Tatra PCC Controller Overhaul and much more. Leipzig Germany 1991. 21 minutes.

If you have ever wondered what the Westinghouse style PCC controller is made up of, and how the pieces work together, this should
explain it all.

Additionally there are scenes of the bogies and other parts.

You will also see a most brutal scrapping of a Tatra PCC trailer car as well as renewing one of those flexible Point blades,
apparently the norm in 1991 in East Germany, a much more recent addition in Melbourne.