ST-LCR3 Alternate Pulse Dual Relays
The logic controlled alternate pulse dual relay unit shall be an RDL ST-LCR3. The unit shall provide two logic inputs. One input shall be designated active when externally held low. One input shall be designated active when externally held high. The unit shall detect the logic input activity and shall provide a momentary pulse when the input becomes active and shall provide a separate momentary pulse when the input becomes inactive.  Each pulse output shall provide SPDT dry switched relay contacts and an open collector, which shall be labeled SLAVE.

The unit shall operate from either of the logic inputs. The logic input that is externally pulled low to activate shall be pulled up to 5 Vdc by the unit and shall require current sink of less than 1 mA to pull low.  The logic input that is externally pulled high to activate shall require no more than 1 mA to activate, and shall become active for dc input voltages exceeding 2.5 Vdc. This input shall operate normally for input voltages up to 24 Vdc.  Both inputs shall be compatible with logic levels generated by 3.3 V and 5 V logic circuits.

The unit shall be equipped with two sets of pulse outputs:  “start pulse” and “end pulse”.  Each pulse output shall be equipped with an open collector capable of sinking at least 25 mA and shall also be equipped with relay contacts. The relay contacts available at the terminal block shall be Form C rated to switch 60 W at a current of up to 2 A. The relay shall be a sealed high-reliability type specified to provide more than 1,000,000 operations. Upon actuation, the relay contacts and open collector shall remain active for 250 mS nominal. Each pulse output shall be equipped with an LED that illuminates while the output is active.

The unit shall be constructed in an electrically non-conductive, thermally conductive enclosure. Internal circuitry shall be protected from moisture and vibration using a thermally conductive compound that permanently secures the circuitry within the enclosure.

The face of the unit shall provide graphical labels identifying wiring connections and operating controls. Indicators shall be oriented toward the front edge of the unit.

Connection to external wiring shall be provided using a fixed terminal block on the edge of the unit. The terminal block shall accept wiring gauges from 14 to 22 and shall include a positive electrically conductive mechanism to prevent wire abrasion by the terminal screws.

The unit shall measure 3” (7.6 cm) x 1.6” (4 cm) x 0.7” (1.7 cm) and be compatible with all RDL STICK-ON mounting accessories. The unit shall be supplied with a two part re-closable polypropylene fastener system equipped with a rubber adhesive that bonds to low surface energy materials.

Power requirements shall be 24 Vdc ground-referenced with a maximum current not exceeding 100 mA with no load connection between the open-collector slave output terminals and the power supply. The unit shall utilize an external power supply. The unit shall be engineered, assembled and tested in the U.S.A. and be specified for continuous duty in professional installed systems. The unit shall be specified for operation in an ambient temperature between 0 and 55 degrees C. The unit shall comply with relevant EMC requirements and shall bear the CE marking.

The unit shall be an RDL ST-LCR3.