Society of Robots - Robot Forum
Electronics => Electronics => Topic started by: rsimp on May 31, 2013, 07:30:10 PM
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I am new to this...and I have a odd project. I plan on having a 12 volt source (a brake light feed) that activates a window motor to lift a heavy object and lower that object back down once the power is removed from brake light. There is going to be ~90 degrees of travel which I plan on controlling with limit switches. The problem that I am having is wiring the darn thing to go back down.
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What I originally wrote was not quite right. But, yes you do want to use an H bridge. Either one to control both motors or two bridges - one for each. The inputs to the bridge to control enable, forward / reverse will be the combination of brake on / off and limit switches.
What is your brake actuated sign going to say to the driver behind you?
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It is not a sign... it is an active-aerodynamic wing. Each of the two motors, one for each side, had a 16amp fuse and were on their own circuit. Do you have a suggestion for the type of H bridge for this application?
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You'd need a 20A or higher rated H-bridge. You *can* build these on your own, using H-bridge drivers chips and power MOSFETs, but that typically requires a lot of trial, error, blown parts, and frustration. Buy something that works.
One of these per motor would probably be robust enough: http://www.pololu.com/catalog/product/759 (http://www.pololu.com/catalog/product/759)
Make sure to secure the VMot input against load dumps from the starter with a 16V 5000W TVS diode.
If you don't need solid state, two SPDT relays per motor could work, too.