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Reply To: Controlling 12-volt heaters with a power relay

Home Forums Infrastructure and Equipment Controlling 12-volt heaters with a power relay Reply To: Controlling 12-volt heaters with a power relay

#18607
Braedon
Participant

    @shicks I wanted to run by what my thought process is with these relays and some of the questions I have now that I have purchased a few. I think my questions are general enough that you should be able to help me with them. I am looking to connect the Seeed relay to the D10-D11 grove terminal on the Mayfly. This would connect the relay’s SIG pin to D10 and the NC pin to D11 and supply it with switched 5V power.

    There is a Wiki page made by seeed studio (https://wiki.seeedstudio.com/Grove-2-Coil_Latching_Relay/#with-arduino), but I am having a hard time following it because in the sections where they talk about the rising and falling edge of the SIG pin, they mention both the NC and NO states, and it isn’t really clear which state (NC/NO) is associated with edge (rising/falling). When I mess with it on my own, it seems that the NO state occurs when I drive the SIG pin low, and the NC state occurs when I drive the SIG pin high. Is that correct?

    I’m not entirely sure how to use the six screw terminals, but my thought is that I would connect the positive terminal of my battery to one of the NO relay terminals (such as 1NO), and then I would connect all of the heater positive leads to the other NO relay terminal (such as 2NO). I would also take all the negative leads of the heaters and connect them straight to the battery ground. I would then turn on the switched power on the Mayfly when my 15-minute mark came up, drive D10 low, and then turn the switched power off. This would turn on the heaters by making the connection between the battery and the heaters’ positive leads. When my data logging was complete for that interval, I would want to turn of the heaters, so I would turn the switched power back on and drive D10 high to close the relay. I could then turn the switched power off until the next 15-minute marker came.

    Is this a sound approach to this problem?