ESP8266 Community Forum

- Wed Jun 08, 2016 12:52 pm #48795 Hi thanks for the reply, ok,

The MOSFET link you provided is maybe a bit oversized/overrated if your relay is small and doesn't consume much current.

Also, the MOSFET need to have low Vgs, below 3V, which is not case in the one you provided.
I would rather use something like AO3402, or 2N7000 if you don't want surface mounted.

The Relay is 5v but it is powering an AC light at 230v, just before I order some 2n700, is it absolutely certain that the P2N2222A will not work for this project (only for time sake) if I can do what I need to do with what I currently have would be great.

The circuit look like, although I would use another MOSFET instead of the 2N3903, with pulldown on its gate

OK so pretty new to reading these things can you confirm I understand and elaborate on the questions I have please:

with pulldown on its gate

do you mean connect the gate to the 3v positive ?

PORT C-2, I am guessing this GPIO2?

- So from GPIO2 (if above is correct) add a 1k resistor

- Add a 2n700 (if you confirm a P2N2222A is not enough) by connecting to the middle pin after the resistor.

- Connect the right pin off to GND (I am powering this by a 9V battery through a regulator) so would that be to 3.3v ground yes or the ground on the 5v side of the board or does it not matter?

- Connect the left pin to a 10K resistor and then what is the 12V after that ?

- Also connect the left pin to a 2n700 (if you confirm a P2N2222A is not enough) connecting it to the right hand pin of the 2nd MOSFET then also that pin to GND, again if so to 3.3V ground ?

- Also connect GND to the middle pin?

- Connect the left hand pin of the 2nd mosfet to the IN pin of the relay ?

Sorry if got mixed up but at this moment that is what I can make out from that diagram, which may be totally wrong lol.

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- Wed Jun 08, 2016 1:20 pm #48796 I've finally found a more perfect schematic on google :

BTW, the R2 is not really useful, you can simply remove it.
Another BTW, low cost TO-92 mosfet I've suggested is 2N7000, not 2N700.

- Wed Jun 08, 2016 1:29 pm #48797 Thanks I will try work this one out soon, was my break down of how the first one worked correct ?

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- Thu Jun 09, 2016 1:52 am #48847 That bad huh ?

I have some 2N-7000 on their way, thanks for taking me through, would be great if you let me know if I was on the right track with the diagram.

Thanks again.

Amazing selection of ESP8266 and ESP32 modules can be found here.