Governor for electric’s is now supported.

[RC Mike]

I just read on another forum that there is a bug in the firmware that will not allow it to work with electric helicopters.
　

UPDATE:
They fixed it. I see on the other forum that the production version on the firmware has a 1:1 gear ratio option and logic that is designed for electric helicopters.

[kevinator9]

Link?

[RC Mike]

It’s way down starting at 2-13-2011.
http://rc.runryder.com/helicopter/t6...top=1297767053

[dharwood]

Not being an electric flier, I may be missing something here.

In a nitro craft, we put a magnet on the driveline to sense engine rpm (actually 2 for balance, but the sensor only sees one). When using an esc, the esc has access to the engine by being tied to it and seeing the phase pulses on the windings, so it knows engine rpm.

You could affix a magnet to the motor can and use a sensor just like a nitro craft and still be able to use the 750's intergal gov ? It would work but is a messy solution with problems of slinging the magnet off, positioning etc....

However, if you used an optical sensor with a reflective stripe on the can, (.250 wide reflective tape), feed the output of the optical sensor to the 750, this would be an easy to implement solution and would not require anything but sticking a piece of tape to the motor can, mounting a sensor to see it and plugging it in.

Ideas? Thoughts? Seems like an easy solution to me. Someone shoot me down

Dale

[Andy from Sandy]

There isn't a bug with the governor. You have not read the thread correctly. Even on a nitro if you wanted to put a magnet on the main gear you would need to put enough magnets to fool the system into seeing as many pulses as it would of with the sensor looking at the engine rpm.

This is exactly what CSM did with its revlock product when the T-Rex 600 E first came out. They produced inserts that fixed into the main gear.

The only bug is you might need to do some maths to convert the number of pulses to an actual rpm.

[Jafa]

Originally Posted by RC Mike

It’s way down starting at 2-13-2011.
http://rc.runryder.com/helicopter/t6...top=1297767053

There is no mention of a bug in the Futaba governor in that thread
They are just discussing how to wire a nitro governor up to an electric heli

The phase sensor is one method
Using magnets and funny gear ratios is another

[Jafa]

Originally Posted by dharwood

However, if you used an optical sensor with a reflective stripe on the [motor] can...

The problem is that the can gets hot, 50~65 deg C
Secondly the can is often spinning in the region of 20K to 28K
which may be a tad fast for some sensors and governors
Finally - the can is carefully balanced - don't disturb that

Originally Posted by dharwood

Someone shoot me down

Bad choice of words - we don't want people shot down - lol

[RC Mike]

Could I use the lowest gear ratio (3:1) and set the headspeed to 667 to get 2000 headspeed. Do you think that would work?
　
Why don’t they just allow a 1:1 gear ratio like Youngblood and eMultoGov does?
　


?????????????????

[Andy from Sandy]

This would suggest that Futaba have either been working on this unit for some time and didn't expect the take up of electric models or they just didn't expect people to want to use this governor as ESCs have one already.

So you know then that with the sensor on the engine fan, bell or backplate and a typical gear ratio of 8 or 9 on a nitro there would be no reason to allow a ratio of 1:1.

Put 3 magnets on the main gear equally spaced for balance and set the ratio to 3:1.

[dharwood]

Bad choice of words - we don't want people shot down - lol

How true

Brings back memories of the 72mhz days for sure..........

As for switching time, a quick look at the first sensor I found (raw sensor data) max switching time is 115khz and max ambient temp is +85c so I don't think either would be a problem.

Just thinking out loud,

Dale

[Jafa]

It could be a firmware or hardware problem
It could be a sampling frequency problem
It could be a scope oversight - not imagining what other uses people will put the device to

For example the RevMax governor/limiter works across the rev range 9,500 to 20,500

Sensing the headspeed at gearing ratio's of 1:1~3:1 is much less granular
than watching the nitro motor RPM

Many of the governors have a resolution of 6 to 20 RPM - on the engine
That will detect headspeed changes of 0.7 to 2.35 RPM on the heli head

If you wire the sensor directly to the main gear the smallest change you can detect is 6 to 20 RPM
That (and the governor gearing setting) is why people put multiple senors on the main gear,
to get increased resolution and RPM...

[velocity90]

Not a problem. Going to use the YGE build in gov anyway

[RC Mike]

They fixed it. I see on the other forum that the production version on the firmware has a 1:1 gear ratio option and logic that is designed for electric helicopters.

[Dr.Ben]

TO REITERATE:

There was never a bug in the 750 firmware. I misposted in the referenced thread that the 750's lowest supported gear ratio is 3:1. It is not. It does and always has supported 1:1 similar to that available on some other products on the market.

I'm current using 4.7:1 on my 750/Hirobo SDX by having a single magnet in a collar on the t/r counter shaft.

Ben Minor

[torana74]

Just to clarify.... the 750 gov can be used on an electric with a phase sensor??

I'd really like to give one of these a try and being able to use the gov on electric is a big bonus

Vas

[Felt]

I do not know why people are so hot and bothered by the Gov in electric mode. I use the gov feature on my ICE and it works great. Why do we need to seperate govs if the esc already has one?

[flymustangs]

Originally Posted by Felt

I do not know why people are so hot and bothered by the Gov in electric mode. I use the gov feature on my ICE and it works great. Why do we need to seperate govs if the esc already has one?

Because the governor can be very predictive if it knows inputs to the other controls. It's still not very clear how much the CGY750 utilizes this, but the vbar uses the throttle, cyclic and collective inputs from the TX to "predict" a pending change in head speed and changes the actual throttle signal to the motor/engine before the change in head speed actually occurs.

The CGY750 manual says "Feed Forward Option allows the CGY750 to consider other control functions during operation". I'm just not sure yet, what that means. There isn't much else in the manual on the subject.

[benwhite22]

As a consequence of the integration of the FBL unit and governor, the governor can react to pitch and tail rotor inputs before it actually sees a dip in the head speed due to the changing torque requirement. This is the "feed forward" control. You cannot achieve this if the governor and FBL unit are seperate components.

[benwhite22]

Originally Posted by torana74

Just to clarify.... the 750 gov can be used on an electric with a phase sensor??

I'd really like to give one of these a try and being able to use the gov on electric is a big bonus

Vas

The CGY750's governor will utilize a traditional magnet/hall effect sensor method of measuring head speed for both nitro and electric models. There has not been any indication that a phase sensor, like that used by the Eagle Tree system and others, will be available for the CGY750.

[Felt]

Sweet! I learned something today. Thanks for explaning that...

Originally Posted by flymustangs

Because the governor can be very predictive if it knows inputs to the other controls. It's still not very clear how much the CGY750 utilizes this, but the vbar uses the throttle, cyclic and collective inputs from the TX to "predict" a pending change in head speed and changes the actual throttle signal to the motor/engine before the change in head speed actually occurs.

The CGY750 manual says "Feed Forward Option allows the CGY750 to consider other control functions during operation. I'm just not sure yet, what that means. There is much else in the manual on the subject.