Arduino - Brushless DC Motor + Rotating power coupling? - Page 2

Symon · 10th August 2008, 10:28 PM

Quote:

Originally Posted by NotoriousTetris

http://blog.makezine.com/archive/200...ing_power.html

Had a look at that, pretty viable option right now. Only need to carry small amounts of current, and Rotary Transformers can only transfer AC current cant they?

For low currents it will be fine. Don't try it for currents over 5A or so, or your bearings won't last too long

NotoriousTetris · 10th August 2008, 10:34 PM

Quote:

Originally Posted by Symon

For low currents it will be fine. Don't try it for currents over 5A or so, or your bearings won't last too long

Awesome, was only needing those bearings to transfer 5v to the arduino, at a low current.

NotoriousTetris · 27th August 2008, 1:19 AM

Well have received the ESC and a DC brushless motor (just incase the HDD one didnt work out). Cant get the ESC to work. Attach it to power, no beeps, nothing. Would it be an issue that I'm using a PSU to supply it with power? Using the 12v rails.

Do I need to get a programmer card?

Any help appreciated.

Technics · 27th August 2008, 7:05 AM

Is the motor attached? It probably won't produce any beeps without one. Most brushless ESCs actually use the motor as the "speaker". It may also have an issue if it isn't getting servo pulses. Even with the throttle at it's lowest setting on rc gear the pulses are still there and many systems will treat the absence of these as a faiure. All ESCs I've seen are desined to stop the motor as a safety feature under these conditions.

I'd need to know model numbers to be more specific.

You shouldn't need a programmer card.

NotoriousTetris · 27th August 2008, 9:18 AM

Quote:

Originally Posted by Technics

Is the motor attached? It probably won't produce any beeps without one. Most brushless ESCs actually use the motor as the "speaker". It may also have an issue if it isn't getting servo pulses. Even with the throttle at it's lowest setting on rc gear the pulses are still there and many systems will treat the absence of these as a faiure. All ESCs I've seen are desined to stop the motor as a safety feature under these conditions.

I'd need to know model numbers to be more specific.

You shouldn't need a programmer card.

Hmm, Yes the motor is attached. I'm begining to think that I am not completing the throttle circuit correctly. I'm trying to replicate the throttle function with an Arduino.

Also, the 'THR' I think it is, the data line, it has a 5v rail on it, does it require power? Because when I plugged the 5v rails into the Arduino, the Arduino powers on??

Confused.

Technics · 27th August 2008, 10:45 AM

The ESC most probably has a battery eliminator circuit. This means it is has an on board regulator for powering a receiver (via the 5V line) so it doesn't require a second battery.

The 5V rail should be left disconnected in your case as you're powering the Arduino already. Only ground and the throttle signal need to be connected.

Are you using the HDD motor or the new one you purchased?

Do you access to an oscilloscope for looking at the servo pulses from the Arduino?

The Touch · 27th August 2008, 10:54 AM

The 5v will be due to the ESC having a Battery Eliminator Circuit commonly reffered to as a BEC. This takes power from the main battery and supplys 5v for the receiver and servos. You will not need to supply the ESC with any power besides the main battery/supply.

NotoriousTetris · 27th August 2008, 11:13 AM

I guess it does have a BEC then. Have tried so many different methods of pulsing the throttle signal. At uni now, have rented out a remote control car, going to see if we can try and make it work via its servo system.

What exactly is a throttle signal? Can it be achieved via PWM or is it an analogue signal?

The Touch · 27th August 2008, 11:19 AM

All servos and ESC's are pwm

Technics · 27th August 2008, 11:31 AM

The ESC will expect servo pulses.

See this link http://www.epanorama.net/documents/motor/rcservos.html.

For the throttle channel 1mS is no throttle and 2mS pulse width is full throttle. The ESC can usually be calibrated though.

27th August 2008, 7:05 AM	#19
Technics Member Join Date: Apr 2002 Location: Brisbane, Australia Posts: 566	Is the motor attached? It probably won't produce any beeps without one. Most brushless ESCs actually use the motor as the "speaker". It may also have an issue if it isn't getting servo pulses. Even with the throttle at it's lowest setting on rc gear the pulses are still there and many systems will treat the absence of these as a faiure. All ESCs I've seen are desined to stop the motor as a safety feature under these conditions. I'd need to know model numbers to be more specific. You shouldn't need a programmer card. __________________ Disclaimer: Any statements made in this post that are not based on historical fact are forward-looking statements. Any forward-looking statements made in this post represent Technics's best judgment as to what may occur in the future. However, the actual outcome and results are not guaranteed and are subject to certain risks, uncertainties and assumptions (“Future Factors”), and may differ materially from what is expressed.

27th August 2008, 10:45 AM	#21
Technics Member Join Date: Apr 2002 Location: Brisbane, Australia Posts: 566	The ESC most probably has a battery eliminator circuit. This means it is has an on board regulator for powering a receiver (via the 5V line) so it doesn't require a second battery. The 5V rail should be left disconnected in your case as you're powering the Arduino already. Only ground and the throttle signal need to be connected. Are you using the HDD motor or the new one you purchased? Do you access to an oscilloscope for looking at the servo pulses from the Arduino? __________________ Disclaimer: Any statements made in this post that are not based on historical fact are forward-looking statements. Any forward-looking statements made in this post represent Technics's best judgment as to what may occur in the future. However, the actual outcome and results are not guaranteed and are subject to certain risks, uncertainties and assumptions (“Future Factors”), and may differ materially from what is expressed.

27th August 2008, 10:54 AM	#22
The Touch Member Join Date: Nov 2003 Location: Perth Posts: 483	The 5v will be due to the ESC having a Battery Eliminator Circuit commonly reffered to as a BEC. This takes power from the main battery and supplys 5v for the receiver and servos. You will not need to supply the ESC with any power besides the main battery/supply. __________________ Help me find out the name of this song! Last edited by The Touch; 27th August 2008 at 10:55 AM. Reason: Beaten :(

27th August 2008, 11:19 AM	#24
The Touch Member Join Date: Nov 2003 Location: Perth Posts: 483	All servos and ESC's are pwm __________________ Help me find out the name of this song!

27th August 2008, 11:31 AM	#25
Technics Member Join Date: Apr 2002 Location: Brisbane, Australia Posts: 566	The ESC will expect servo pulses. See this link http://www.epanorama.net/documents/motor/rcservos.html. For the throttle channel 1mS is no throttle and 2mS pulse width is full throttle. The ESC can usually be calibrated though. __________________ Disclaimer: Any statements made in this post that are not based on historical fact are forward-looking statements. Any forward-looking statements made in this post represent Technics's best judgment as to what may occur in the future. However, the actual outcome and results are not guaranteed and are subject to certain risks, uncertainties and assumptions (“Future Factors”), and may differ materially from what is expressed.

27th August 2008, 1:19 AM	#18
NotoriousTetris Member Join Date: Jul 2006 Posts: 136	Well have received the ESC and a DC brushless motor (just incase the HDD one didnt work out). Cant get the ESC to work. Attach it to power, no beeps, nothing. Would it be an issue that I'm using a PSU to supply it with power? Using the 12v rails. Do I need to get a programmer card? Any help appreciated.

27th August 2008, 11:13 AM	#23
NotoriousTetris Member Join Date: Jul 2006 Posts: 136	I guess it does have a BEC then. Have tried so many different methods of pulsing the throttle signal. At uni now, have rented out a remote control car, going to see if we can try and make it work via its servo system. What exactly is a throttle signal? Can it be achieved via PWM or is it an analogue signal?