[dorkbotsea-blabber] Anyone understand motor controllers

[Bill Beaty]

At 11:32 AM 2/26/2007 -0800, you wrote:
>I seem to be having an issue with driving a windshield wiper motor with an L298 motor controller. I'm using a computer power supply 12v 6amp that when I hook up direct seems to have plenty of torque but I loose too much through the motor driver. If anyone has any Ideas on a stronger motor controller or any way to overcome my limits let me know!


The question is: what resistance do those transistors have when
turned on (how much voltage is lost through those transistors?)
The datasheet only gives that voltage loss for 1amp and 2amp,
it's listed as VCEsat.  It's pretty bad: worst case of five 
volts lost for two amps.   For more than 2amp load, this loss
would be larger.

So maybe your motor is only seeing a few volts, and the
transistors are eating the rest.

Yes, several chips wired in parallel would help a lot.

  datasheet for L298
  http://www.st.com/stonline/books/pdf/docs/1773.pdf




> 
>Thanks in advance Victor
>
>
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William J. Beaty              http://staff.washington.edu/wbeaty/
Research Engineer             UW Chem Dept,  Bagley Hall RM74
beaty at chem.washington.edu     Box 351700, Seattle, WA 98195-1700
ph:206-543-6195 fax:206-685-8665