Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[Raen]

Hi,
I have an action P80 speed controller that works OK for the initial 10-30 seconds of being switched on but then gets stuck full throttle.Any ideas on what could be causing this issue?
Setup is as follows:

[rnli12]

Can you clarify whether you move it to full throttle then gets stuck or goes straight to full throttle after 20 -30 secs?

[malcolmfrary]

ESCs do speed control by switching the output transistor off a lot.  For permanent full speed, it isn't switching off.  It could be broken, and unable to switch off, it could be the circuit driving it not telling it to switch off.  Using it over time might allow things to warm up and show the problem.  "Over time" in electronic terms, can easily be 10-30 seconds.


Has it ever been damp?

[Raen]

Can you clarify whether you move it to full throttle then gets stuck or goes straight to full throttle after 20 -30 secs?

I switch the Tx on followed by the ESC/Rx, wait a couple of seconds for auto ranging to set. Following this the unit functions correctly switching from forward to reverse with no issues. after a little while approximately 20-30 seconds although sometimes longer it cuts out, no throttle response whatsoever and then suddenly goes full throttle with no response from the stick at all.

[Raen]

ESCs do speed control by switching the output transistor off a lot.  For permanent full speed, it isn't switching off.  It could be broken, and unable to switch off, it could be the circuit driving it not telling it to switch off.  Using it over time might allow things to warm up and show the problem.  "Over time" in electronic terms, can easily be 10-30 seconds.


Has it ever been damp?

Has not been damp.

[malcolmfrary]

The PIC chip is a device that uses its internal program to look at the signal coming in and use that information to tell its two outputs (forward/reverse and speed) whether to be switched on or off at any one time.  the direction control is either on or off and is easy to measure with a simple meter.  The speed part of the circuit is switching very rapidly, and a simple meter is not much use, something more sophisticated is needed. 
Either the output FET is broken and won't switch off, or something earlier is broken and telling it to not switch off.  This could be either a component between the power FET and the IC, or the IC itself.
That's about as far as my knowledge goes with this item.  The on line .pdf of the assembly instructions - https://www.componentshop.co.uk/pdf/P80.pdf  - doesn't go into enough detail, such as PCB tracks, to let me guess what any particular component is doing.

[Raen]

Thanks Malcolm. Seems to confirm my fears that something has gone bad in the P80.

What Brushed ESC's would everyone recommend for a 540 motor on a 1/48 MV Cervia Tug build?
It appears P80's are out of stock, would a Hobbywing 1060 be sufficient?

[malcolmfrary]

Certainly one of my first choices.  I don't know whether to fully trust the current handling claim, but for anything that a P80 should have handled I think it should be fine.  Unless somebody knows better.

[rnli12]

What batteries are you using LiPo?

[HMS Invisible]

Thanks Malcolm. Seems to confirm my fears that something has gone bad in the P80.
...

Raen, reply comments about RC equipment depends as much on information that you supply as much as the knowledge or experience of the reply posters.

What radio set do you use? A back link to an instruction download or upload of a section on failsafe setting would help greatly.
The moment I saw your diagram I thought receiver has gone into voltage failsafe
 

[malcolmfrary]

This is where a servo tester comes in.  A proper viable signal independent of whatever the radio might introduce.  A servo plugged into one of the other outlets lets you see what is being offered if the tester is not one that has a display.

[HMS Invisible]

From Topic: Reverse Issue - March 07, 2021 - (Read 797 times) Where a lot of sensible replies were made and useful information for this new thread already exists.

Hi Bob,
I am using a Futaba 6EX 2.4ghz

From the PDF download for Futaba 6EX 2.4ghz

Battery Failsafe
Your  system  provides  a  second  safety  function  called  Battery  Failsafe. When  the  airborne  battery  voltage  drops  below 
approximately 3.8V, the battery fail safe function moves the throttle to a predetermined position or fast idle, if you haven’t set it.
If this happens, you should immediately land! If you need to increase throttle for your landing approach, you may temporarily
reset the failsafe function by moving the throttle stick to idle, after which you’ll have about 30 seconds of throttle control before
the battery function reactivates

It would also be prudent to do a visual health check on a double pole relay because, if overheated, the thermoplastic case can shrink and cause a short if wired to provide reversing function in a single-transistor speed controller.

[Raen]

Thanks Invisible,
Correct I am using a futaba 6ex and associated Rx. The reverse issue was sorted after the SLA was fully charged, I also have a 6.4v LiFePo4 battery (SLA replacement) that I have tested the setup with. The stuck throttle happens on both battery setups.

[Mrs Stav]

Why not simply email Iain at Component shop they will Help with your problem




Mrs Stav

[Netleyned]

Why not simply email Iain at Component shop they will Help with your problem









Mrs Stav

Seems the most logical thing to do

[HMS Invisible]

Thanks Invisible,
Correct I am using a futaba 6ex and associated Rx. The reverse issue was sorted after the SLA was fully charged, I also have a 6.4v LiFePo4 battery (SLA replacement) that I have tested the setup with. The stuck throttle happens on both battery setups.

You charged the battery according to the March 2021 thread but there is no indication you set the failsafe to kill throttle in a boat speed control (~1.5msecond). Out of the box, the 6EX failsafe will idle a forward-only aircraft esc but send a boat speed control to nearly full reverse at the default 1.1ms setting.
 
And although the LiFePo4 nominal voltage is 6.4 volt the charge setting and votage when LiFePo4 comes off the charger is 7.2 volt.

There is every indication the receiver is going into failsafe and no indication of a P80 issue.

[C-3PO]

Is the throttle stick on the handset "sprung" to return to the center position?

If not on "power on" of the transmitter/receiver what position is the throttle control stick?

I have a similar radio that came with a model I purchased - with default settings it "screams" at you to set Zero Throttle (stick down) on power on - the only way to power on without the alarm is Zero throttle/stick down... or go into the user unfriendly setup

Regards
C-3PO

[Raen]

Ok following the advice here and from Iain over at Component Shop i was able to further troubleshoot my problems and determine it was a power delivery issue to the Rx.I ended up sticking the Rx on the SLA and the other components on the LiFePo4 and it all functions exactly as expected in this configuration.I will be ordering separate Rx battery packs to ensure I don't have this problem in the future.
As my knowledge of RC components is very limited I am grateful to be able to get such great advice from you all on this forum, a special thanks to Mr Invisible who had this problem worked out pretty well instantly it is much appreciated.
Regards, Tim