Hey guys,
This is the circuit I typically use when controlling a relay using a GPIO on a microcontroller:
I just noticed that a microcontroller that I am wanting to use has 2 output modes... a normal mode that can source 0.5mA, and a high drive mode that can source 5mA.
Are either of these 2 modes adequate to activate the transistor? The relay I am using has a coil current draw of 40mA @ 12VDC by the way.
How do you make this calculation to know how much current draw would be needed to activate the transistor? Thanks and any help/advice is greatly appreciated!
This is the circuit I typically use when controlling a relay using a GPIO on a microcontroller:
I just noticed that a microcontroller that I am wanting to use has 2 output modes... a normal mode that can source 0.5mA, and a high drive mode that can source 5mA.
Are either of these 2 modes adequate to activate the transistor? The relay I am using has a coil current draw of 40mA @ 12VDC by the way.
How do you make this calculation to know how much current draw would be needed to activate the transistor? Thanks and any help/advice is greatly appreciated!