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A single, reasonably tough general purpose BJT is all you need here if you really want a simple solution. The 2N4401 supports up to 600mA of current and has a 40V Vce max. As long as the relaysolenoid on the door lock has a snubber it doesn't need to be any more complicated than this unless you need isolation or have other constraints.

Note that below I've drawn a relay because it was easy, but you can just as well put your door lock's solenoid coil where the relay is drawn below (they're effectively the same type of device).

enter image description here

I have exactly this setup on an ESP8266 controlling a 24V relay and it works great. I'm using an old 2N2222, which are long since obsolete, but the 2N4401 would do just the same.

A single, reasonably tough general purpose BJT is all you need here if you really want a simple solution. The 2N4401 supports up to 600mA of current and has a 40V Vce max. As long as the relay has a snubber it doesn't need to be any more complicated than this unless you need isolation or have other constraints.

enter image description here

I have exactly this setup on an ESP8266 controlling a 24V relay and it works great. I'm using an old 2N2222, which are long since obsolete, but the 2N4401 would do just the same.

A single, reasonably tough general purpose BJT is all you need here if you really want a simple solution. The 2N4401 supports up to 600mA of current and has a 40V Vce max. As long as the solenoid on the door lock has a snubber it doesn't need to be any more complicated than this unless you need isolation or have other constraints.

Note that below I've drawn a relay because it was easy, but you can just as well put your door lock's solenoid coil where the relay is drawn below (they're effectively the same type of device).

enter image description here

I have exactly this setup on an ESP8266 controlling a 24V relay and it works great. I'm using an old 2N2222, which are long since obsolete, but the 2N4401 would do just the same.

Source Link
J...
  • 171
  • 5

A single, reasonably tough general purpose BJT is all you need here if you really want a simple solution. The 2N4401 supports up to 600mA of current and has a 40V Vce max. As long as the relay has a snubber it doesn't need to be any more complicated than this unless you need isolation or have other constraints.

enter image description here

I have exactly this setup on an ESP8266 controlling a 24V relay and it works great. I'm using an old 2N2222, which are long since obsolete, but the 2N4401 would do just the same.