Need Help with Photon Output Voltage

Hello Particle Community! noob here

I am trying to connect a door strike to my Particle Photon. One problem that I am facing right now is that my door strike takes in 12V, whereas the particle pins (from D0-D7) doesn’t provide enough voltage. Then I brought a step up transformer, was hoping to amp up the voltage to unlock the door strike. Unfortunately, it can unlock only once.

Particle pins(D2 & D3) in the following set up that I did for two different versions are initially set to ON:

Particle pin (D3, GND) produced 2.8V-----X----> Transformer -----X----> Door Strike = Failed

  • The set up above failed because the transformer requires at least 3V to function.

Particle pin (D2 & D3, GND) produced 3.2V-------> Transformer output reads 15.8V--------> Door Strike = Failed

  • The set up above, the transformer output(-/+) reads 15.8V but once I connect the output wires to the door strike will unlock ONLY once. In addition, if I turn the particle pin (D3 &D2) OFF and then ON again, the door strike will not respond. In order to unlock it again I have to manually connect and disconnect either the positive or negative wires from the door strike. (I used D2 & D3 because I made an app that performs digitalWrite ON/OFF on them)

If you guys have a solution to solve this please leave a comment below. Thanks for taking the time to read this!

I’d personally use a 12V power supply and regulate that down to power your Photon. The Photon itself is not made to deliver power to such devices, and you may end up damaging it.

Thank for responding @Moors7!

If anybody have suggestion of how I can power on the door strike either directly or indirectly, please let me know!

Thanks in advance!

You’d need a way to switch 12V via 3.3V signal.

That can be done via relays or transistors.
There are several threads about relays, as this way seems the easiest for you to wrap your head round.


I would use the Particle Relay Shield with the Photon. One of the four relays can be used to energize the lock strike safely. But the other advantage is that it takes 12V in and has a built-in power supply to power the Photon. So with a single 12V DC 2A power supply you can power both the Photon and the lock strike.


Thanks @ScruffR!
This is exactly the information that I am looking for. I been googling about transistors and how they work and it’s the missing piece of my project! Thank You!

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