L298 Back EMF - Page 2 - Electronic Circuits Projects Diagrams Free

fabbie · 20th November 2004, 04:14 PM

I read through the datasheet and went through other tutorials.
Yeah the current sensing is to control the current alright.
but how did u guys get the value ranging from 0.1 ohm to 0.9ohm?? is there somekind of calculation??

**Nigel Goodwin** · 20th November 2004, 04:16 PM

Quote:

Originally Posted by fabbie

According to the website you provided,
http://www.iitk.ac.in/eclub/Circuit/l298.htm
It said here that the current sensing here will control the current according to VS/R and will be provided to the load.

If the Vs is 12V. wouldnt the current be EXTREMELY big? 120Amp.
Mind teaching me how u did u attain the value of 0.1ohm?

VS isn't the supply voltage, it's the sensing voltage - the voltage dropped across the sensing resistor.

I've just had a look at the datasheet for the 298, there's no internal current limiting at all - it just provides a connection pin from the bottom of the H-Bridge to ground. By inserting your own resistor in there you can monitor the motor current, and do whatever you want with it.

By using a 0.1 ohm you would probably have to amplify the voltage to make it to a useable level.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

20th November 2004, 04:14 PM	(permalink)
fabbie	I read through the datasheet and went through other tutorials. Yeah the current sensing is to control the current alright. but how did u guys get the value ranging from 0.1 ohm to 0.9ohm?? is there somekind of calculation??