FTL Design
History of Technology

Weston Electrical Instrument Corporation
Model 30 Sensitive Relay

The Model 30 sensitive relay uses an instrument movement as a relay. The applied voltage or current causes the pointer to move from its rest position on the left hand contact, and to make with the right hand contact. See movement details below.

Shown are two versions of the Model 30, made perhaps 40 years apart. On the left is serial number 427; on the right, serial number 11020. The design changed only in small details.

Model 30 No. 427	Model 30 No. 11020
No. 427 movement
No. 11020 movement