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. It has a built-in circuit breaker and the ORANGE handle activates the horn/whistle circuit. There are two variations:
Variation A: Has a B terminal post. Produced 1953.
Variation B: Does not have the B terminal post.
This transformer is popular among operators today due to the multiple fixed voltage circuits.