Hi folks, newbie here and working on my first project. I'm trying to build a DC motor controller using the PWM output pins to drive a Darlington transistor (TIP122) using an emitter ground configuration (with an IN4004 and 100nF capacitor across the motor terminals). To be honest, I have not designed hardware for quite a while so I'm a bit rusty (and analog circuits were never my strength) and can use some help.
I'm using an Uno board and I noticed the output pins are rated at 40mA. I'm supplying 12V for the motor and I expect it to draw about 1A and I wanted to make sure the PWM pins provide enough juice at the base to properly drive the transistor. The reference circuit uses a 1K 1W resistor to drive the base and I'm worried that the transistor might be drawing too much current and damage the board. The motor controller is designed for continuous duty.
Any help will be greatly appreciated!
Thanks,
- K.