I've been looking at various explanations on limiting current for stepper motor control and I need some help. Can anyone verify my logic here? Thanks in advance.
I hooked up the following circuit today and blew out the H-Bridge.
http://img52.imageshack.us/img52/3073/ss20100427003002.png
The Current Sense resistors R4 and R5 are 2Ω, 10W. I think I figured this out based on the explanations over at Jones on Stepping Motor Current Limiting. It looks like with a supply voltage of 24V, a winding resistance of 1.2Ω, and a current sense resistance of 2Ω, I'd be pushing about 7.5A.
Based on what Jones says I need to use a 12Ω resistor to limit current to under 2A. That means 2A*2A*12Ω=48W. Is this correct? Thanks for any input.
I hooked up the following circuit today and blew out the H-Bridge.
http://img52.imageshack.us/img52/3073/ss20100427003002.png
The Current Sense resistors R4 and R5 are 2Ω, 10W. I think I figured this out based on the explanations over at Jones on Stepping Motor Current Limiting. It looks like with a supply voltage of 24V, a winding resistance of 1.2Ω, and a current sense resistance of 2Ω, I'd be pushing about 7.5A.
Based on what Jones says I need to use a 12Ω resistor to limit current to under 2A. That means 2A*2A*12Ω=48W. Is this correct? Thanks for any input.