HRDM Series - Delay On Make Timer

Littelfuse Delay on Make Relays
The HRDM Series combines an electromechanical relay output with microcontroller timing circuitry. It offers 12 to 230V operation in five ranges and factory fixed, onboard, or external adjustable time delays with a repeat accuracy of ±0.5%. The output contact rating allows for direct operation of heavy loads, such as compressors, pumps, blower motors, heaters, etc. This series is ideal for OEM applications where cost is a factor.

Operation (Delay-on-Make)
Upon application of input voltage, the time delay begins. The output is de-energized before and during the time delay. At the end of the time delay, the output relay energizes and remains energized until input voltage is removed.
Reset: Removing input voltage resets the time delay and output.

Access specifications, certifications, check availability and order parts below

Catalog #Input
Voltage (V)
Storage Temperature (F/C)Time Delay RangeSample capableCompare
HRDM12012VDCNon-isolated SPDT-40° to 85°C (-40°F to 185°F)0.1s - 10s onboard knobNo
HRDM3112S24VDCNon-isolated SPDT-40° to 85°C (-40°F to 185°F)12s fixedNo
HRDM413M120VACNon-isolated SPDT-40° to 85°C (-40°F to 185°F)3m fixedNo
HRDM415M120VACNon-isolated SPDT-40° to 85°C (-40°F to 185°F)5m fixedNo