HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Feb 19, 2004, 05:21 PM
Registered User
WingMan33's Avatar
Chicagoland Area
Joined Oct 2003
412 Posts
Use a switch as a WOT control for big brushed motors

Hello I am replacing these with true controllers and thought I would post some pick of how to use a switch for brushed motor high amps 50 .simple cheap and glitch free, but you have to carry a reciver battery with this set up .
WingMan33 is offline Find More Posts by WingMan33
Reply With Quote
Sign up now
to remove ads between posts
Old Feb 19, 2004, 05:22 PM
Registered User
WingMan33's Avatar
Chicagoland Area
Joined Oct 2003
412 Posts
you can see it size not to bad.
WingMan33 is offline Find More Posts by WingMan33
Reply With Quote
Old Feb 19, 2004, 05:28 PM
It's the last plane honey
SlowRider's Avatar
Granite Bay, CA USA
Joined Jul 2003
2,133 Posts
Wingman,

Thanks for the info. What plane is that in the pics?


Andy
SlowRider is offline Find More Posts by SlowRider
Reply With Quote
Old Feb 19, 2004, 06:02 PM
Registered User
WingMan33's Avatar
Chicagoland Area
Joined Oct 2003
412 Posts
Slow rider A EL BEE. 48 inch Wing.
WingMan33 is offline Find More Posts by WingMan33
Reply With Quote
Old Feb 19, 2004, 08:45 PM
Dax
There is no spoon
Dax's Avatar
Vancouver BC Canada
Joined Aug 2002
1,016 Posts
so its all or nothing, WOT or dead stick.... might make for intresting landings
Dax is offline Find More Posts by Dax
Reply With Quote
Old Feb 19, 2004, 09:54 PM
Senior Member
zagisrule!'s Avatar
Edgewood, NM
Joined Jan 2002
1,038 Posts
Geez! How much current are current will those microswitches take?









-Matt
zagisrule! is offline Find More Posts by zagisrule!
Reply With Quote
Old Feb 19, 2004, 10:39 PM
Our Daddy and Heli Junkie
Fred Bronk's Avatar
In Heli Wonderland
Joined Aug 1999
22,801 Posts
Not 50 amps continuous without melting!!
Fred Bronk is offline Find More Posts by Fred Bronk
Reply With Quote
Old Feb 20, 2004, 02:29 AM
Registerd Beaver
Smokin' Beaver's Avatar
Australia, WA, Warwick
Joined Jul 2003
3,573 Posts
I pulled some out of an old 3 phase instantaeous Hot Water System ages ago & they were rated at 25Amps AC @240 volts.
At under 12V, 30-50 Amps for short periods might work.
Phil
Smokin' Beaver is offline Find More Posts by Smokin' Beaver
Reply With Quote
Old Feb 20, 2004, 08:16 AM
Senior Member
zagisrule!'s Avatar
Edgewood, NM
Joined Jan 2002
1,038 Posts
I think it would be a bit safer to just use some MOSFET's to switch the load....no, it is not very hard

All you need is a resistor per FET and a grounding resistor to ground for the whole group. You could then use your switch(even a very small one would work) to apply current to the bases and turn your motor ON.






-Matt
zagisrule! is offline Find More Posts by zagisrule!
Reply With Quote
Old Feb 20, 2004, 08:32 AM
RIP Ric
Andy W's Avatar
Marietta, GA
Joined Jun 1999
43,312 Posts
Remember, there are many folks in this hobby who do not know the first thing about basic electronics - this prohibits many exisiting wet-fuel modelers from trying electric. Some models even come with a wiring harness and a switch, and instuctions on how to connect this to a servo to turn on the motor!!
..a
Andy W is offline Find More Posts by Andy W
Reply With Quote
Old Feb 20, 2004, 10:31 AM
Registered User
vintage1's Avatar
East Anglia, UK
Joined Sep 2002
29,703 Posts
Just take a look at what your car starter motor takes to switch about 200A...and see how its dine.

IMHO the weight disadvantages of a mechanical switch outweigh the efficeincy loss on a MOSFET, and frankly, a brushed ESC is not much more expensive than a servo and a relaible switch, and receiver battery.
vintage1 is offline Find More Posts by vintage1
Reply With Quote
Old Feb 20, 2004, 02:00 PM
BEC
Registered User
BEC's Avatar
Auburn, Washington USA
Joined Jan 2001
12,939 Posts
Everything old is new again?? We used to do this sort of thing, many years ago before ESCs were as good as they are now (small, light, fairly inexpensive, good BECs and other features).

For 15 or 20A you can get away with a setup like that for some time. Sooner or later the switch will die. Been there, done that.

At 50A I'm surprised the switch doesn't weld itself together in the on position the first time you use it. A switch that's big enough to actually take that load and switch it safely (remember you WILL be switching the startup current of the motor) is large, heavy, and not cheap.
BEC is online now Find More Posts by BEC
Reply With Quote
Old Feb 20, 2004, 02:33 PM
Our Daddy and Heli Junkie
Fred Bronk's Avatar
In Heli Wonderland
Joined Aug 1999
22,801 Posts
"At 50A I'm surprised the switch doesn't weld itself together in the on position the first time you use it."

Get in, sit down and shut up, were going for a ride!!

I think we have stated our feelings about this very well.
Fred Bronk is offline Find More Posts by Fred Bronk
Reply With Quote
Old Feb 20, 2004, 05:32 PM
Registered User
WingMan33's Avatar
Chicagoland Area
Joined Oct 2003
412 Posts
Wow a lot of Ideas Well it Handles 50 amps at 7.2 volts all day no problem it is rated at 5amps 250volts A.C. they bag a lot. as far as weight yes it is a disadvantage. it is cheap though 3bucks for the switch 14 for a micro servo. .Cheers
WingMan33 is offline Find More Posts by WingMan33
Reply With Quote
Old Feb 20, 2004, 06:33 PM
A Clinger
rclark's Avatar
Butte, MT
Joined Sep 2001
7,075 Posts
Ummm, are you 'sure' your hitting 50 amps with that setup (measured) ???? That setup sure doesn't look like it will unless I am blind (could be I guess...) BTW just because you have a 50A ESC doesn't mean it will be pulling 50A. All it means is the ESC will 'handle' up to 50A.
rclark is offline Find More Posts by rclark
Last edited by rclark; Feb 20, 2004 at 06:36 PM.
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Sold Big Brushed Motors chip.greely Aircraft - Electric - Power Systems (FS/W) 3 Aug 22, 2007 10:00 AM
Sold Big Brushed Motors chip.greely Boats (FS/W) 0 Jul 31, 2007 10:48 PM
Best Speed control for Brushed motors Robbie d Electric Heli Talk 2 Aug 19, 2002 01:54 AM
Looking for good brushed motors 14thflyer Aircraft - Electric - Airplanes (FS/W) 1 Mar 10, 2002 07:12 PM