I have a project where I relay control an external resistive load (1400W 240V). Between the relay and the load there is a thermostat. Relay is a Songle SRD-05VDC-SL-C.
I've tried to visualize it in the schematic. Relay coil is energized all the time. However, when the external thermostat goes from off to on (conductive, happens a few times a minute), the relay clicks a lot in the transition. I'm pretty sure it's in the transition, as the thermostat have a red ON / green OFF light, and the relay clicking always happens when the light changes from green to red.
It's like the coil pressure isn't strong enough to keep the relay closed. I use a 7002 (n-ch mosfet) and 1k base resistor. Base is driven by a 74HC02 (lots of logic behind it).
Would I be better off using another mosfet or reduce the base resistor? What mosfet would be a better choice?