Avoir bad relay trigger during boot

[tparvais]

Hello

I have a standard relay controlled via a mosfet on GPIO D5. 100ko resistor pull down the gate to gnd. And free wheel diode on coil as protection.

I have setup D5 low during boot in espeasy

However, when booting , the relay clicks

Any very simple solution to avoid that ? I don’t have soo much place left on my pcb. Maybe a capacitor to absorb the spike At boot ? Any idea ?

Thank you

[ThomasB]

It sounds like you are doing all the right things. Does this occur during power-up boot, warm boot (reset button), or both boot modes?

If relay click occurs on all boot modes then perhaps D5's internal weak pull-up has been enabled. That would suggest that the 100K ohm external pull-down value is too high; Try 4.7K ohm instead.

- Thomas

[tparvais]

I changed a litle bit the circuit by adding 2 resistors divider + Capacitor 100µF to ground + Zener 3V on the gate to delay introduce a delay.
To activate the relay, I have to send a longer pulse to overcome this delay

It works perfectly and this is simple