I have problem interfacing 8051 controller with relay. I am using 12V relay to ON/OFF. The output port of the controller is set at logic zero, it gives 5V when it isnot active.
But when inputs are applied it works according to the requirement but it gives 2V, when it is active.
So if the relay is active it doesnot gets deactived at this point.
i have attached the relay circuit.
Plz help me, I need help soon.
1K resistor is there between output port and base of the transistor.