ESP8266 Community Forum

- Sat Feb 11, 2017 8:03 pm #62425 I have an esp8266 controlling 3 relays. Thou I use a Transistor to trigger the relay, they still pull a lot of current from the 3v power supply when the coils are energized. I want to make sure that the esp8266 is protected from voltage drops but not sure what way I can do that.
Is a Voltage Regulator the best way to stabilize the voltage?
Is there a Better / Simpler way

- Sat Feb 11, 2017 11:31 pm #62429 I never use the 3.3 volt supply for relays. I either use 5v or 12v. If 5v then I use a linear regulator to supply the 3.3 for the ESP.

The problem with powering relays from low voltages is that the currents need to be higher and it is the larger difference between on and off that causes problems. And on top of that circuit routing is even more important.

It helps to have a good digital scope and to measure right at the module. I solder a pin to the ESP module ground for the scope ground reference. Measure the Vcc at the module's input as well. Sometimes a series inductor can help but it is not a simple thing to get the right type and values. While it can help as far as spikes up and down it doesn't help if your power supply drops.