a relay question

[Etam]

I have a circuit that normally runs at 3-5v and then when triggered, it gets pulled to ground (around .1-2 mv leakage). I want to use this to trigger a relay to close a different low voltage circuit. Can I use the " sainsmart DC 5V Relay Module for Arduino PIC ARM DSP AVR MSP430 TTL Logic" board to achieve this?

 

[Mike_2545]

use the N.C. portion of the relay...when your circuit goes to ground the relay turns off and the contacts are closed...that is, If the circuit can hold open the relay....