Auto max throttle

[jhsa]

Just had an idea. Don't know if it is currently possible..

Reduce the max throttle when the pack voltage goes under the minimum set voltage in ?Telemetry/custom switches?.
Reduce throttle automatically so the battery stays always above that voltage.


When voltage reaches that threshold, the tx automatically starts reducing the throttle accordingly to keep the voltage above it. Don't know if this would be good for helis, but I think it would be good for planes. when it starts happening a lot, you will know that it is time for landing. Batteries won't be damaged..

João

[ReSt]

Thats what I have realized with a PIC processor.
It permanently monitors the battery voltage. It takes the ESC input signal as input and outputs it as long as every cell is above the set limit. When at least 5 contiguos measures of any cell drop below the preset limit, the motor is stopped for one second and (as cell voltage recovers above limit) then restarted. This is repeated for up to three times and then, the length of the output signal is reduced until the cell voltage is again above the limit. From then on you can drive the motor up to the reduced limit that the controller allows.
When the length of the output signal goes below a certain length, the motor ist stopped finally to protect the battery and have at least a small amout of capacity to safely land.

If you stop the motor with the stick, before the output is reduced, you can (later) go to full power again (for a short time, as long as the battery holds above the min voltage).

I also had a version that did not stop the motor but immediately reduced the power to the motor.
But I found it's hard to decide how fast the motor runs, when the model is some hundred meters away.
So you could drain the battery without really noticing it.

After the flight, an LED signals which cell had the lowest voltage.

In addition to this motor controlling function, it also monitors the output pulses of the receiver. If connection to the radio is lost for more than 2 seconds, it will remember it and also signal it via its LED.

With my 35Mhz radio I had communication losses nearly with every flight, while I never saw one with my standard 2.4Ghz FlySky radio, not even with the 3 channel receiver.

Reinhard

[jhsa]

nice.. Now we just need that er9x and openTX do something similar....

[gohsthb]

My esc already does this on it's own. The only thing you add here is an adjustable voltage. It would be best to have the throttle signal decreased rather than cut off. Some esc's will pulse the throttle also, which may be a better indication.
-Gohst

Sent from my LG-P999 using Tapatalk 2

[jhsa]

that's what I meant to say. decrease throttle so the plane will lose power but not cut off. the tx would always try to keep the voltage uinder the programmed value by reducing the throttle accordingly and not cutting it completely when you need some power..

João

[MikeB]

Try this on er9x (a bug I've just found in eepe means you can't test it there, but you probably can't anyway as it doesn't have the telemetry inputs). As I don't think openTx has the "Late Offset" feature, you may need to do the weight and offset for channel 16 differently, or use sub-trim to get the offset.

Custom switch:
CS1: v>ofs FASV 10.0V (or A1/A2 and your low battery limit)
Mixes:
CH15: +100% FULL Switch(SW1) Slow(u15:d15)
Ch16: +20% CH15 Offset(80%) Late Offset
Gvars:
GVAR1: Input(CH16)
Dual Rate:
Throttle dual rate assign to GVAR1
Also, turn Throttle EXPO on so the dual rate affects the whole of the throttle range.

The theory is that when you battery voltage drops below your limit (as set in CS1), CH15 will slowly reduce. Channel 15 will also slowly reduce, but instead of going from +100 to -100 it will only drop from +100 to +60. This value is then available in GVAR1.
GVAR1 reduces the maximum throttle by being assigned to the throttle dual rate. As long as the battery voltage is below the threshold, the max. throttle will continue to reduce (slowly). When, as a result of a lower throttle output, the battery voltage recovers, CS1 turns back on and channels 15 and 16 start to rise, allowing a higher max. throttle. Due to the SLOW setting on channel 15, this doesn't happen quickly and channel 15 will settle, oscillating slightly and slowly, around the required max. throttle allowed to hold the battery voltage.
The channel 16 values for weight and offset allow you to set limits on the throttle adjustment. With the ones I show, the lowest setting of the max. throttle is 60%.
By assigning a switch to the throttle dual rate, you can turn this feature on and off instantly.

Mike.

[jhsa]

Shame I didn't see this berfore I went to the field
Will try this as soon as I have a little time.. that means when everyone goes to bed and I have the night all for myself

Thanks Mike

João