Society of Robots - Robot Forum
Electronics => Electronics => Topic started by: Bajanick on November 19, 2007, 11:48:51 PM
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I have a electric wheelchair I will be using as a base for a rover. I need an Hbridge or motor controller that can whithstand at least 60 amps under normal load.
Can I get away with using this (in the link) type of solenoid for the control of the motors? I know there will be no speed control.
http://www.allelectronics.com/cgi-bin/item/SOL-80/500050/12_VDC_POWER_SOLENOID_.html
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remember to search the forum
http://www.societyofrobots.com/robotforum/index.php?topic=1904.0 (http://www.societyofrobots.com/robotforum/index.php?topic=1904.0)
My blog has some info on using wheelchairs also.... erobots.blogspot.com (http://erobots.blogspot.com)
,Eric
P.S. The solenoid you posted is overkill for a wheelchair motor
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For a heavy robot you'd definitely want speed control - otherwise the jerky motions will break stuff . . .
I quickly browsed around and found these rated at 60A and 120A:
http://www.robotmarketplace.com/marketplace_ifi_esc.html
I'm sure there are plenty more:
http://www.societyofrobots.com/robot_parts_list_electronics.shtml
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i agree,
i will add speed control to my butler robot ,
without speed control its not very smooth and it does break stuff ( if things are loosly mounted..)
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not to mention that those sudden starts reaquire huge currents...
which isnever a good thing when working with batteries. (not without batteries either for that matter ;))
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Ive seen those ifi and vantec controllers but they are pretty expensive. I know I will have a hard time with my budget.
I originally was going to use a vantec that you can hook up an RC directly to but its too much money.
I thought about the auto relays but I cant see how they could handle the startup draw and the stall current, would they?
Thanks.
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The dimensionengineering.com (http://www.dimensionengineering.com) motor drivers can also do RC input, and are much cheaper . . .
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i've used automotive relays on my butler robot and they work fine .
Speed control is the best though.
Look on my blog erobots.blogspot.com
it has info and a video of a robot which uses wheelchair motors and automotive relays . I used two 12V 20Ah batteries - -and i get a really really long lifetime per charge
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I cant see how 30 amp auto relays can withstand the startup current and a stall current of 80 amps or so. When I get a chance I am going to do some tests. Ive seen the dimensions engineering site but they dont have any high current controllers.
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HAve you thought about going to an old scrap yard and looking for an electric car?
you could probably find what your looking for and evn hav speed control.
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You can use two 30 A VNH2SP30s (http://www.pololu.com/products/pololu/0707/) to make a single 60 A H-bridge (assuming you can cool them enough for them to operate at their maximum current ratings), though that's still a little short of your 80 A stall. The dual half-bridge configuration is described on page 14 of the VNH2 datasheet (http://www.pololu.com/products/pololu/0707/vnh2sp30.pdf).