Designing a Relay control from a MCU's GPIO, there are some requirements to take into account.
- Coil Voltage: 3V
- Coil Resistance: [36-45]Ohm
- Relay Voltage: 250Vac // 30Vcc
- GPIO Voltage: 3V3
- Max GPIO Current 4mA // 20mA (depending on pin)
So, even when relay are THR, I'm looking for SMD transistor instead of THR for controlling the relay.
I would like you to share yout opinion about which would be the best option to make this work.
My questions are:
- What do you think about used SMD instead of THR?
- Will transistor be able to dissipate power?
- MCU, would it deliver enough current to activate the base?
Do you have any recommendations?
- EDIT: Added COIL Resistance [36-45]Ohm