Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Paul & Sabrina's cheap DIY 144v motor controller

wjdennis · 03-26-2009, 04:56 PM

Just finished readying the whole thread (whew!). First, congratulations. Great accomplishment. I want one! I just need to learn how to solder now.

I have a question, and perhaps I just missed in an earlier post. The reason you hear the squeal from a Curtis controller (or the growl from a Zilla), is because at low throttle position, the controller cuts the PWM rate from 15K Hz to 1.5K Hz. This is because they found it harder to do current limiting fast enough at 15K Hz PWM. If you're staying at 16K Hz the whole time, how does your controller get around that when Curtis and Cafe Electric didn't?

Thanks. Keep up the great work.

Bill

03-26-2009, 04:56 PM	#671 (permalink)
wjdennis EcoModding Lurker Join Date: Aug 2008 Location: Salt Lake City Posts: 37 Thanks: 0 Thanked 0 Times in 0 Posts	Squeal and Growl Just finished readying the whole thread (whew!). First, congratulations. Great accomplishment. I want one! I just need to learn how to solder now. I have a question, and perhaps I just missed in an earlier post. The reason you hear the squeal from a Curtis controller (or the growl from a Zilla), is because at low throttle position, the controller cuts the PWM rate from 15K Hz to 1.5K Hz. This is because they found it harder to do current limiting fast enough at 15K Hz PWM. If you're staying at 16K Hz the whole time, how does your controller get around that when Curtis and Cafe Electric didn't? Thanks. Keep up the great work. Bill