panel switch box

Last crawled date: 1 year, 10 months ago

the panel switch was named for its tall panels which consisted of layered strips of terminals. between each strip was placed an insulating layer, which kept each metal strip electrically isolated from the ones above and below. these terminals were arranged in banks, five of which occupied an average selector frame. each bank contained 100 sets of terminals, for a total of 500 sets of terminals per frame. at the bottom, the frame had two electric motors to drive sixty selectors up and down by electromagnetically controlled clutches. as calls were completed through the system, selectors moved vertically over the sets of terminals until they reached the desired location, at which point the selector stopped its upward travel, and selections progressed to the next frame, until finally, the called subscriber's line was reached.