I'm very new to this, and also I speak spanish, so please pardon my english and my electronic knowledge.

I'm trying to design the following proyect: Control my deck lights from an RF remote control relay and from a physical 3 way switch.

I'm thinking of something like this: Not Energized Relay - Light Off

First, I would like to know if there's any suggestion to this configuration, but my biggest concern is regarding the time when the relay will stay energized and the light turned off by the switch, I'm afraid that there may be times where the relay can be left energized for weeks, and I don't know if they're design to work like this, or if it could be dangerous, since it'd be installed in a wooden shed. A situation like this: Energized Relay - Light Off

Is there any suggestion to this configuration? Or maybe something else that I can do to manage my objective?

Thanks a lot,

  • \$\begingroup\$ Don't you want your light bulb COM to connect to the switch COM port instead of NC? \$\endgroup\$
    – Daniel V
    Commented Sep 12, 2016 at 15:34
  • \$\begingroup\$ @DanielV: The light bulb is connected corrrectly in the above drawings. \$\endgroup\$ Commented Sep 12, 2016 at 15:51
  • \$\begingroup\$ The circuit will work, but I think that you could suitably replace the 3 way switch with another remote control, and save energy, if you think that the relay will be on for about 50% of the time. \$\endgroup\$
    – CasaMich
    Commented Sep 12, 2016 at 16:01
  • \$\begingroup\$ Aside from the milliamps of power used by the energized relay, it shouldn't be an issue. The relay datasheet probably has on time in years. But I'll let someone more knowledgeable in these designs confirm. \$\endgroup\$
    – Passerby
    Commented Sep 12, 2016 at 16:01
  • \$\begingroup\$ Or replace the existing wall switch with a momentary switch and wire it in parallel to the push button on the relay module. \$\endgroup\$
    – Passerby
    Commented Sep 12, 2016 at 16:03

2 Answers 2


The energized relay going for weeks/months shouldn't be an issue. The bigger question is why bother with a physical 3-way switch? Just get two RF transmitters on the same frequency and put one in the shed in place of the switch.

Or get something like the Lutron Caseta Wireless Switch kit. It comes with a switch and a remote relay. It has a dimmer as an option if you want to dim the light as well. And also has an optional hub so you can turn your shed light on and off from the Internet anywhere in the world.

  • \$\begingroup\$ Why is having a physical switch a problem? \$\endgroup\$ Commented Apr 10, 2017 at 10:00
  • \$\begingroup\$ Presumably the physical switch is so that you can always turn the lights on, rather than fumbling around in the dark trying to find where somebody has hidden the remote control. \$\endgroup\$
    – Simon B
    Commented Oct 4, 2018 at 11:24

That is a good question and here is your answer.

First of all, I think what you're trying to do is to use the circuit as an intermediate switch, hence the energised state.

The answer is to modify the relay to a bistable (latching relay). This way a pulse is sent to the relay to change from off to on and vice versa.

The even better way is to use a 2 x coil latching relay. One coil is for set and the other for reset. Both only need a pulse and they change the state of the relay


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