Thread Tools
Old Feb 19, 2004, 06:21 PM
WingMan33 is offline
Find More Posts by WingMan33
Registered User
WingMan33's Avatar

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 .
Sign up now
to remove ads between posts
Old Feb 19, 2004, 06:22 PM
WingMan33 is offline
Find More Posts by WingMan33
Registered User
WingMan33's Avatar
you can see it size not to bad.
Old Feb 19, 2004, 06:28 PM
SlowRider is offline
Find More Posts by SlowRider
It's the last plane honey
SlowRider's Avatar
Wingman,

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


Andy
Old Feb 19, 2004, 07:02 PM
WingMan33 is offline
Find More Posts by WingMan33
Registered User
WingMan33's Avatar
Slow rider A EL BEE. 48 inch Wing.
Old Feb 19, 2004, 09:45 PM
Dax is offline
Dax
Find More Posts by Dax
Dax
There is no spoon
Dax's Avatar
so its all or nothing, WOT or dead stick.... might make for intresting landings
Old Feb 19, 2004, 10:54 PM
zagisrule! is offline
Find More Posts by zagisrule!
Senior Member
zagisrule!'s Avatar
Geez! How much current are current will those microswitches take?









-Matt
Old Feb 19, 2004, 11:39 PM
Fred Bronk is offline
Find More Posts by Fred Bronk
Our Daddy and Heli Junkie
Fred Bronk's Avatar
Not 50 amps continuous without melting!!
Old Feb 20, 2004, 03:29 AM
Smokin' Beaver is offline
Find More Posts by Smokin' Beaver
Registerd Beaver
Smokin' Beaver's Avatar
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
Old Feb 20, 2004, 09:16 AM
zagisrule! is offline
Find More Posts by zagisrule!
Senior Member
zagisrule!'s Avatar
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
Old Feb 20, 2004, 09:32 AM
Andy W is offline
Find More Posts by Andy W
Registered User
Andy W's Avatar
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
Old Feb 20, 2004, 11:31 AM
vintage1 is offline
Find More Posts by vintage1
Registered User
vintage1's Avatar
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.
Old Feb 20, 2004, 03:00 PM
BEC is offline
BEC
Find More Posts by BEC
BEC
Registered User
BEC's Avatar
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.
Old Feb 20, 2004, 03:33 PM
Fred Bronk is offline
Find More Posts by Fred Bronk
Our Daddy and Heli Junkie
Fred Bronk's Avatar
"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.
Old Feb 20, 2004, 06:32 PM
WingMan33 is offline
Find More Posts by WingMan33
Registered User
WingMan33's Avatar
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
Old Feb 20, 2004, 07:33 PM
rclark is offline
Find More Posts by rclark
A Clinger
rclark's Avatar
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.
Last edited by rclark; Feb 20, 2004 at 07:36 PM.


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 11:00 AM
Sold Big Brushed Motors chip.greely Boats (FS/W) 0 Jul 31, 2007 11:48 PM
Best Speed control for Brushed motors Robbie d Electric Heli Talk 2 Aug 19, 2002 02:54 AM
Looking for good brushed motors 14thflyer Aircraft - Electric - Airplanes (FS/W) 1 Mar 10, 2002 08:12 PM