ESP8266 Community Forum

- Thu Nov 29, 2018 11:41 am #79326 Hi Guys,
I have a oje-ss-105hm 4 pin 5 volt relay that we have tested by powering with 2.9 volt, this shows a current drawing 5 milli amps.
I would like to power an ESP8266 Lolin board with a standard 9 volt battery to the Vin pin, then control the relay with pin D4.
My intention is to use a voltage divider from the 9 volt dropping to 4.5 volt to power a vibrating motor which I have salvaged out of an old Nokia 6110, this would be switched by the relay.
Can I connect directly to pin D4 ?

Regards
Simon

- Fri Nov 30, 2018 3:44 am #79334

I have a oje-ss-105hm 4 pin 5 volt relay that we have tested by powering with 2.9 volt, this shows a current drawing 5 milli amps.

I highly doubt that, I've yet to see a relay that needs that low amount of current.
The relay you're referring to is rated at 91mA@5V, an ESP8266 is only capable of delivering 12mA@3.3V.

You'd better drop the relay (it's a bit weird, in my eyes, to use a relay to switch a vibrator motor as you're using a coil to drive a coil similar in size) and use a MOSFET instead.

Assumption is the mother of all f*ckups. At least: that's what I'm assuming.