The Lionel TW Transformer was produced from 1953 until 1960. It generated 175 Watts of power. This transformer is unique among all of those that Lionel made during the Post War period because it has an independent power source for the constant voltage accessory circuits that is completely separate from the main coil that controls the variable voltage circuit.

The power light uses an L53 lamp, and this transformer has a built-in circuit breaker and the ORANGE handle activates the horn/whistle circuit.

There were seven different instruction sheets that were issued under the No. 21-80. All have BLUE ink on WHITE paper and are dated 9-53, 8-54, 12-55, 1-57, 5-57, 5-58 and 6-59.

There are two variations:

Variation A: Has a "B" terminal post. 1953 Production.

Variation B: Does not have the B terminal post. 1954-60 Production.

This transformer is popular among operators today due to the multiple independent fixed voltage circuits.