Jim's Robot - Pulse Width Modulator (PWM)

Jim's Robot - Pulse Width Modulator (PWM)
Version 1 - 8/29/2006
Large Size: GIF or TIFF	Pulse width modulation (PWM) creates an on/off signal at a specific duty cycle(s) to run the motor at less that full speed. This board uses an array of resistors that can be individually included (parallel) in the circuit to allow for up to 64 different duty cycles. An PCF8574 I2c IO chips receives the speed from the bus, opens the transistors and a logic pulse for the selected cycle is created. This logic level pulse is UNABLE to drive the motors directly and is fed into the TTM Motor Power Boards. I placed the cycle resistors in a 14pin dip socket so that I may change the duty cycles by changing the values.