Going Electric

How does one turn the power on/off on an electric CL plane?
Is it done with radio or how?

If you aren't flying in a contest, you can use a radio.

In summary, you flip a switch on the airplane. The motor runs for awhile, then stops. From what I have seen, there is a microcontroller that puts out a series of pulses to a motor controller. The microcontroller emulates an RC receiver, and the motor controller emulates an RC servo. One can imagine the historical reasons for this arrangement. The microcontroller typically includes a timer that shuts the motor off after six minutes or so: enough to do a stunt pattern. Low battery voltage or overload may also cause the microcontroller or motor controller to shut off power. What starts the series of pulses from the microcontroller to make the motor start turning seems to vary from system to system. It's combinations of hardware and software switches, some of which I'd be reluctant to trust.

Howard Rush
Bellevue, WA

>It's
>combinations of hardware and software switches, some of which
>I'd be reluctant to trust.
>
>Howard Rush
>Bellevue, WA


Would you care to elaborate?


Kim.

I wouldn't trust a system that has power applied to all its components (or could have without my knowing it) and which relies on software remaining in some quiescent state until it's told to start the motor. Offhand, I don't know of any systems like this on the market. I don't know how yours works. I do know that yours employs a safety device that prevents some kid from walking up, flipping a switch, and turning the motor on. I think that is a virtue.

Howard Rush
Bellevue, WA

>From what I have seen, there is a
>microcontroller that puts out a series of pulses to a motor
>controller.

because it takes the place of the commutator of a brushed motor. Why the motor manufacturer doesn't provide it is IMHO ludicrous.

The microcontroller emulates an RC receiver, and

because for "safety" the ESC turns the motor off unless it detects a signal from a receiver.

>the motor controller emulates an RC servo.

That is a throttle servo as it varies the current to the motor.


The controller also turns off power when battery power dips below a certain level, if this feature wasn't there it would fry a LIPO battery pack and possibly the plane.

Using a brushed motor and Ni-Cads all that you need is an on off switch and fuse to protect the motor from burning up.

Woody,
In PA we typically use a "stand-alone" timer which also functions as the throttle control to the ESC. In addition to this, one can also mount an arming "switch" (usually a shorted connector that you plug into the female version of the same connector that is mounted on the fuselage of the plane. The arming switch connects the battery voltage to the ESC which then power ups the timer/throttle. Some timer throttles (JMP-2 for example) have a button to push which then starts the timing cycle. Others (like the Ztron) start the timing cycle once the arming switch is plugged in.

People that fly carrier actually use a third line to control a potentiometer which sets the throttle pulse to the ESC. That way they can control the motor during the flight. I think the scale guys use something similar.

Here is a link to a vendor of both the JMP-2 and Ztron timers. There are others out there too.

http://www.bsdmicrorc.com/products.cfm?catID=10006

>People that fly carrier actually use a third line to control a
>potentiometer which sets the throttle pulse to the ESC. That
>way they can control the motor during the flight. I think the
>scale guys use something similar.

There's such a thing as "Electric Navy Carrier"?
Is it a seperate class?

Go over and look up the CL Carrier yahoo group. There has been quite a lot of effort expended in developing electric carrier.

Bill Lee

Over on Stunthangar, http://stunthanger.com/smf/index.php , there is a Carrier Forum with postings on Electric Carrier Events. I think the main effort right now is with Skyray Carrier events.

Thanks guys. That was enlightening. I appreciate everyone's response.