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Old Sep 24, 2008, 01:54 PM
Castle's Chaos Corner
Bernie Wolfard's Avatar
Olathe, KS (next to the Castle)
Joined Jun 2001
1,649 Posts
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Ian Asked: brushed with reverse vs. high power brushed

Dear Bernie,
While we are on the subject, can you tell me what exactly the difference is between brushed with revers v.s high power brushed? I know the motors are connected to the ESC differently but does the high power brushed give more power to the motor? In the manual it does not say. Other than reverse, why would you use one over the other?
btw I have my mamba monster setup with brushed with reverse even though I am not using reverse (option 1 proportional forward brake w/o reverse) should I use a high power brushed then>
Your help is gratefully appreciated.
ian


Answer:

There is a persistent myth that a speed controller somehow affects the power a motor can put out rather than its real function of just controlling the motor’s speed. The motor draws current from the battery and the battery determines how much power the motor has. The only specification in an ESC that affects how much power a motor gets from the battery is the ESCS internal resistance. The lower the resistance the more power the motor can get from the batteries. A higher amp rated ESC will not allow the motor to get more battery power. A lower resistance ESC will. There is a second function the ESC performs that relates only to three phase brushless motors. This is how well the ESC runs the motor. There is a wide variance on how well and ESC runs a brushless motor, but this has no affect on brushed motors.

Our systems are designed for three phase brushless motors. To run a brushed motor only takes a small fraction of the ESCS capabilities as the ESC only has to control motor speed, it does not have to run the motor. With the ‘Brushed With Reveres’ the ESC uses two of the three phases to run the motor. Set up this way the ESC has the same amp handling ability as it does for brushless. A very high Kv motor (low turn) can pull more power than ESC can handle, which causes it to overheat. Set up for ‘High Power Brushed’ all three phases are combined more than tripling the power handling ability of the ESC. The Sidewinder can handle 18 turn brushless motors, down to 8 turn in High Power mode. The Mamba Max can run down to a 12 turn motor, at High Power down to a 2-turn motor (which will burn up after about 4 seconds of running ). We have not tested the brushed motor limits on the Monster Mamba. On ‘Brushed With Reverse’ is should be good to at least 8 turn and on high power to -8 turn.

Bernie
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Last edited by Bernie Wolfard; Sep 24, 2008 at 01:54 PM. Reason: smilies
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Old Sep 24, 2008, 06:46 PM
Registered User
Ontario Canada
Joined Oct 2004
244 Posts
Bernie thanks for clarifying the brushed setup.
In my case I am running a 450W brushed motor powered by a 24V battery. If Amp= watts/volt does that mean the motor is pulling 18.75 Amps (450w/24v) ? If this is the case then I don't need to run in high power setup (correct?). Since, the monster can handle a lot more current then I suspect when I use full throttle with the ESC controlling the motor that should be almost equivalent to just attaching the battery directly to the motor?

ian
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Old Sep 25, 2008, 09:10 AM
Castle's Chaos Corner
Bernie Wolfard's Avatar
Olathe, KS (next to the Castle)
Joined Jun 2001
1,649 Posts
Ian,

An electric motor will pull as much power as it needs to do the job at hand. The only limit in a brushed motor is when the brushes quit working effectively, in a brushless motor there are no limits. The watt rating of a motor is the point at which the motor will run without overheating, not how much it will draw.

The load on the motor is what determines how many watts it will produce. The important question is how many watts does it take to do what you want. What are you using this in and how are you calculating load? If the load is in fact 450 watts then your calculations are correct and either the Sidewinder or the Mamba Max will work in 'Brushed with Reverse' mode. The Mamba Monster is overkill and unnecessary.

Bernie
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Old Sep 25, 2008, 01:14 PM
Registered User
Ontario Canada
Joined Oct 2004
244 Posts
Hi Bernie,
I know that the mamba monster is overkill. But the mamba monster is currently the ONLY RC ESC IN THE WORLD that is commercially available (trust me I have spent a lot of time searching) that can take 24V input and run a brushed setup with proportional braking. The closest thing I have come to is the Syren25 from Dimension Engineering. The main reason I bought the Monster over the Max or sidewinder ESC is because I need 24V input to run my 450W brushed motor.

ian
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Old Sep 26, 2012, 04:29 AM
Right Rudder
PittSpecial's Avatar
USA, FL, Orlando
Joined Nov 2010
8,934 Posts
Any updates?

I am looking for something to control a large 3 inch diameter Brushed Pump Marine Motor and the ProBoat 50-AMP with BEC has worked very well, however, it has exhibited a momentary thermal cut-off even with forced water jacket cold plate cooling on my very large 6-foot Plywood PT311 (Patrol Torpedo) RC Electric Boat.

I like to consider something robust and capable of running without thermal limitations. To give credit to the ProBoat ESC it came back to life less than one minute and motor came back in operation.

I found the TorqueMaster BR-XL as it comes with stock with Auto lipo LVC, Full drag brake, instant reverse, and 100% reverse throttle settings, onboard 6v 5a switchmode BEC, 80a continuous, Fully Computer programmable via Castle Creations Castle Link with instant firmware upgrades, and most importantly, Designed and made in the USA! ???

Anyone from Castle has any suggestions?

Thank you for your time and attention.
Carlos

PT311 RC Electric 6-Foot Boat Model 3rd Test Run at Moon Port Modelers RC Club Titusville, Florida 09-22-2012 (2 min 1 sec)
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