I'm trying to use a 2-Coil Latching Relay like TXS2SA-L2-3V for powering up a ESP8266. My idea is to activate the relay by setting the first coil to high and deactivate the coil by setting the second coil to high. In my circuit i will set the second coil to high at the end of the code by the esp8266. I need the latching (holding the power) function of it. Because when somebody activtes the Deep Sleep function to early, I have no electricity to power the esp8266.

My question is:

What kind of circuit I must use? I have no idea where I can start.

I have a regulator that can be enabled via de EN signal.

Thanks in advance!

TPS61200 regulator

  • 2
    I've read your question twice, but it's still unclear to me what your actual question is. – Gerben May 13 at 15:30
  • My idea is to activate the relay by setting the first coil to high...? How? – Majenko May 13 at 15:33
  • deactivate the coil by setting the second coil to high. ...? How? – Majenko May 13 at 15:34
  • You control a latching relay of this sort in the exact same way as a normal relay. What is your problem? – Majenko May 13 at 15:56

You use a latching relay of this form in the exact same way as a normal relay - it's just there's two of them.

One coil you want to control with a button (power on) and the other with a transistor (and possibly an "off" button as well).

schematic

simulate this circuit – Schematic created using CircuitLab

Press ON to latch the relay into the ON position (NO -> COM). Activate M1 or press OFF to latch the relay into the OFF position (NC -> COM).

  • Excellent! Thank you for your help. What kind of transistor can I use? Both ESP8266 and the relay work with 3V3. Thanks in advance. – Jose Alfredo Sanchez Diaz May 14 at 9:29
  • If use an n MOSFET with a VGS below 2v. – Majenko May 14 at 9:30
  • 1
    I have great luck with the IRLZ44N on 8266s; cheap w/low rds+vgsth – dandavis May 15 at 0:18

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