Hello Guys,
I know that this miniature 3V DC motor need minimum 270mA @ 3.3V which is direct PIC output pin cannot supply that high current need. That’s why I use ULN2003 to drive up current from PIC to higher current then activate the 5V SPDT relay to throw the contactor to the other 5V side. (see photo)
Connection seems OK.
I try direct connecting motor to VDD & VSS of PIC and the motor is running. Just want to make sure motor is OK.
Then I put simple program code (ON RD0 continuously all times) – I want to confirm the current from output pin RD0 is not sufficient. And yes, motor is not running, but if put LED it will light up all times. Very true, I need to use ULN2003 to drive the motor.
I look everywhere (datasheet, google other blogs) but they were all the same connection to use ULN2003. I followed the connection. But the relay is not ‘clicking’ to show it is energized.
I again direct connect motor to output pin 16 of ULN2003 which is supposed to be output for pin 1 input. No response to the motor. I suspect the ULN2003 is not working.
Relay is working fine. I have tested the relay alone with 0V and 5V at 270mA & 100mA to both coils without problem.
Thanks.