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Old Dec 13, 2014, 09:59 AM
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Can I run a brushless motor without a reciver?

I have a motor I want to use for a project (a mini-prop powered car) before I put it in my plane. I have the right ESC and battery, but do not have time for shipping and don't want to waste money on something I won't ever use again. I only need for it to turn on and off ex. When I connect or disconnect two wires. Is it possible?
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Old Dec 13, 2014, 10:04 AM
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No.
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Old Dec 13, 2014, 10:18 AM
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No, you need either a Tx/Rx or a servo tester to produce the same sort of signal. No signal, no motor running.

Steve
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Old Dec 14, 2014, 05:30 AM
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You can also build a little interface with a PIC or an attiny(arduino) that create the pulse signal as your RX .
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Old Dec 14, 2014, 05:41 AM
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The easiest way is to use a servo tester as a throttle. That will generate the same PWM signal that the receiver does and you can run the motor with a variable throttle that goes from off the full throttle.

Servo testers can be a cheap and simple as these:

http://www.ebay.com/itm/like/131308449441?lpid=82

or you can get one with a display of the PWM rate and that will also handle more testing tasks and types of servos:

http://www.ebay.com/itm/like/131308449441?lpid=82

Also available from places like deal extreme and bang good and the like...

Jack
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Old Dec 16, 2014, 04:54 PM
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Simple : connect the wire for 2ms, disconnect for 50ms, reconnect for 2ms etc...
I don't remember for the 50ms, but i'm sure for the 2ms
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Old Dec 17, 2014, 02:39 PM
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They use a circuit refered to as a timer in control line planes where there is no receiver.
It waits an amount of time after switch on, then runs the motor at a preset speed for a preset amount of time.
There are applications where you can run a bldc motor using a microcontroller, but your into some complex electronics for that.
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Old Jan 07, 2015, 01:51 AM
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thanks for all the help! i acctualy ended up not needing to use what i was making with the motor anyway.
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Old Jan 07, 2015, 08:15 AM
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Well although you didn't need to do it. eFlite makes a control line timer motor control device that you can use for this purpose. It has a timer that you can set in one minute increments, and a motor speed setting.

http://www.e-fliterc.com/Products/De...ProdID=EFLA172
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Old Jan 13, 2015, 02:13 PM
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Quote:
Originally Posted by earlwb View Post
Well although you didn't need to do it. eFlite makes a control line timer motor control device that you can use for this purpose. It has a timer that you can set in one minute increments, and a motor speed setting.

http://www.e-fliterc.com/Products/De...ProdID=EFLA172
I made several of those a few years back using a MicroChip PicChip. Still have a few of them. Cost is a buck or two each.

Based on the work in doing the microcontroller software, now, I'd just buy that e-flite unit!
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Old Jan 13, 2015, 02:47 PM
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Quote:
Originally Posted by earlwb View Post
Well although you didn't need to do it. eFlite makes a control line timer motor control device that you can use for this purpose. It has a timer that you can set in one minute increments, and a motor speed setting.

http://www.e-fliterc.com/Products/De...ProdID=EFLA172
Unfortunately it has been discontinued....which is a shame because most of the C/L timers still available cost about 3 times more.

Steve
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Old Jan 22, 2015, 11:03 PM
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Hey all - long time lurker, first time poster here.
I have a near identical problem, and I hope you smart people can point me towards the best solution.

I need a push-button solution for control of a brushless motor that is always in hand.

I am running a red brick 60A, driving a Turnigy Aerodrive SK3 - 5055-280kv brushless. (I don't know if it matters, but I am using a li-ion 6 cell 22.2V, 6600Mah)
When the motor is running at the ideal speed, it is pulling 20A (though I don't know what PWM signal is being sent to the ESC)

I am looking for an off the shelf solution - something premade, that is relatively available. I don't know if there is a MOSFET that would produce the correct signal, or what -
I saw someone suggest the following " build a 5V-powered 555 circuit with a 20ms 'off' and an adjustable 1-2ms 'on' period."
I wonder if anyone knows where to get a premade board with these characteristics?

Any and all help would be hugely appreciated! you guys are awesome
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Old Jan 22, 2015, 11:19 PM
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Ready made:
http://www.hobbyking.com/hobbyking/s...vo_Tester.html
DIY(not much work but more expensive if you have to buy parts!)
http://www.sentex.ca/~mec1995/gadgets/servo4.htm
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Old Jan 22, 2015, 11:23 PM
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Haha, That is what I have sitting on my workbench.

It works well enough for testing (as is it's namesake) but I need something that I can seal up inside a case, with the only access being a power switch and a pushbutton trigger to drive the motor.

I really need a chip or board that can be activated by a momentary switch, and sends the appropriate PWM signal to the ESC.

Any more help would be appreciated
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Old Jan 23, 2015, 03:39 AM
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Just reprogram the ESC controller chip. Should be easy enough. No need for extra complications.
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