jrz126
Active Member
I need a way to determine the % on time for a PWM signal. I believe it runs at a constant 100Hz.
I'm working on designing this simulator for a locomotive computer (Brightstar). Right now I'm working on the Traction Alternator and Exciter. The Brightstar puts out a PWM signal which drives the exciter to generate the field that causes the traction alt. to start generating.
The loco computer is connected to a unix based system (Nighthawk). which handles all of the I/O. Now the problem lies in reading this signal in my plant model for my exciter.
Looking at the schematic, I think I can tap into the PWM signal at an optoisolator (+5V-0V). (I have no idea what kind of waveform it is or the frequency (I think its 100hz)). I would then need a way to convert the % on time into an analog voltage which I would then connect to an analog input on the nighthawk.
I'm working on designing this simulator for a locomotive computer (Brightstar). Right now I'm working on the Traction Alternator and Exciter. The Brightstar puts out a PWM signal which drives the exciter to generate the field that causes the traction alt. to start generating.
The loco computer is connected to a unix based system (Nighthawk). which handles all of the I/O. Now the problem lies in reading this signal in my plant model for my exciter.
Looking at the schematic, I think I can tap into the PWM signal at an optoisolator (+5V-0V). (I have no idea what kind of waveform it is or the frequency (I think its 100hz)). I would then need a way to convert the % on time into an analog voltage which I would then connect to an analog input on the nighthawk.