Expansion Relay Board
(Item #555) EXPANSION RELAY BOARD contains a 12 volt DC relay with a double pole, double throw (DPDT) set of contacts which is usable on its own as a relay or as an expansion relay which plugs into the 2 pin connector (provided) of the TRAK-DT family of current sensing detectors to add extra contacts to those devices. The Trak-DTRL requires the use of one set of it's contacts in order to provide more contacts. Hence, adding one 555 to it would yield a 3PDT set of relay contacts and not a 4PDT unless the set used to drive the 555 relay can also drive something else operating from the 12vDC used to operate the 555's relay coil. |
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Relay Contacts - electrical diagramRelay contacts are used on most all of our Signaling Components. These are used since they are the most forgiving when mis-wiring occurs and they provide for electrical isolation of the load to the circuit. When the relay is relaxed the "C" Common terminal is connected to the "N/C" Normally Closed. When the relay is activated the "C" Common terminal is then connected to the "N/O" Normally Open terminal. The relays used on our circuitry contain Double contact sets indicated by section A and section B. Remember a relay is nothing more than an electrically activated switch! |
