All About Aurora Postage Stamp Trains
4991: 4-Circuit Relay
4991 is a relay with four circuits (4PDT latching). It is not self de-energizing, which means it can burn out if the wrong controller is used or if it is operated improperly.
The box contains one relay (usually wrapped in tan paper) and an instruction sheet for both 4991 and 4992. There are two versions of the instruction sheet. One is two-sided with German text.
The other is single-sided with illustrations only.
ATI later sold the relay in blister packs.
