I believe that early transformer only has four contact points, or four speeds. With the rheostat wired in beyond it you'd have finer speed control. Just my best guess.I noticed that on the original box for the Lionel #81 rheostat, it shows the rheostat wired between the track and the transformer. BUT the transformer shown has a throttle.
What is the purpose of the rheostat, when your transformer has a throttle? Thanks.
If left alone, yes. But the sliding nature of the control arm allowed it to be used for speed control when attached to a fixed voltage output.I thought the rheostats job was to create a different fixed voltage, 6v for lights for example.