Optipower ultra guard

[echopoint]

Originally Posted by Mike680

Oh, I think I just found a hole. If the flight battery becomes unplugged or otherwise electrically disconnected, hitting throttle hold won't stop current from getting back through the throttle plug or BEC wires to the internal BEC, will it? It will just send a motor stop signal to the ESC. Or, will throttle hold still prevent the motor from trying to run back powered through the internal BEC because the RX is now telling it to not run? I've just confused myself.

So, yeah, just use the cheap and easily installed diode, I guess. I honestly don't know why these internal BECs just don't incorporate some sort of back flow diode protection in the first place.

Hitting throttle hold when the flight battery fails will stop current from going from the UG to the ESC to the engine as the TH turns off the motor. What we are worried about is what happens between the time the failure occurs and the pilot notices and hits throttle hold. When I discovered this issue when I was testing, it resulted in a very hot IKON when the ESC tried to spool up my motor using a way under-rated 2S battery. My battery also got quite hot.

[Mike680]

Originally Posted by echopoint

Hitting throttle hold when the flight battery fails will stop current from going from the UG to the ESC to the engine as the TH turns off the motor. What we are worried about is what happens between the time the failure occurs and the pilot notices and hits throttle hold. When I discovered this issue when I was testing, it resulted in a very hot IKON when the ESC tried to keep the engine running under my governor using a way under-rated 2S battery.

Yes, I guess it doesn't take long at all for that current pull and resultant heat to build up. I can't believe this diode protection isn't in place by the manufacturers already. There is no reason ever for current to flow back through an internal BEC to the motor. I'm still wondering why this issue hasn't been encountered and discussed by a lot more people before because it seems to be pretty serious.

I've never owned a large Hobbywing ESC with an internal BEC. Do they have an extra BEC power lead in addition to the throttle lead to handle the higher current? I know the Castle 20A external BEC has two power leads. If so, then you'd need two diodes for total protection.

[echopoint]

Originally Posted by Mike680

Yes, I guess it doesn't take long at all for that current pull and resultant heat to build up. I can't believe this diode protection isn't in place by the manufacturers already. There is no reason ever for current to flow back through an internal BEC to the motor. I'm still wondering why this issue hasn't been encountered and discussed by a lot more people before because it seems to be pretty serious.

I've never owned a large Hobbywing ESC with an internal BEC. Do they have an extra BEC power lead in addition to the throttle lead to handle the higher current? I know the Castle 20A external BEC has two power leads. If so, then you'd need two diodes for total protection.

The hobby wing ESC I have has 3 leads. 1 throttle, 1 BEC, and 1 for governor. I would need 2 diodes. I ordered 10.

I suspect people don't complain about this, because either:

a) They aren't using a backup
b) They are not using the internal BEC, so they already clipped the power lead
c) They haven't noticed there is a problem.

[Mike680]

Originally Posted by echopoint

I suspect people don't complain about this, because either:

a) They aren't using a backup
b) They are not using the internal BEC, so they already clipped the power lead
c) They haven't noticed there is a problem.

Well, then they don't apply to my question about reports of this issue. I'm sure plenty of people use backup units with ESCs that have internal BECs. I was specifically going to put a Hobbywing 120A on a 550 to clean it up some by replacing a Castle 120HV and 20A external BEC, but now I'm not so sure because I want to use my Ultraguard. I really like the Hobbywing ESCs I already have, but they're on smaller models not using an Ultraguard.

[joanpeca]

I also own a HW100AV3 and noticed the issue we are talking about just when I installed the OUG, because I had the transmitter off and when I unplugged the main pack to check that OUG kicked in, I still could hear the "no throttle signal" tones coming from the motor. I reported about it in the Hobbywing forum and I was suggested to install two Becguards or other reliable diodes. Since then, in my "to-do" list I have an entry "buy and install diodes in my Goblin 500". Now at least I know what diodes I should buy, thanks mmel for the suggestion.

[akabud]

Anybody find a source for the diodes in the US?

[CZorzella]

Originally Posted by akabud

Anybody find a source for the diodes in the US?

http://www.digikey.com/product-detai...5GI-ND/2153405

Datasheet: http://www.vishay.com/docs/88671/mbr16xx.pdf

[echopoint]

Originally Posted by joanpeca

I also own a HW100AV3 and noticed the issue we are talking about just when I installed the OUG, because I had the transmitter off and when I unplugged the main pack to check that OUG kicked in, I still could hear the "no throttle signal" tones coming from the motor. I reported about it in the Hobbywing forum and I was suggested to install two Becguards or other reliable diodes. Since then, in my "to-do" list I have an entry "buy and install diodes in my Goblin 500". Now at least I know what diodes I should buy, thanks mmel for the suggestion.

That is the same exact ESC I am using. I bought the following diodes:

http://www.mouser.com/ProductDetail/...zfxXgYKg%3d%3d

Datasheet: http://www.mouser.com/ds/2/427/mbr16xx-106332.pdf

[joanpeca]

Thanks for the suggestion, echopoint!

[Locktite]

So I just bought 2 Ultraguards for 2 of my machines which are running HW 160A ESC's..I haven't gone through this whole thread yet, but it seems like the ultra guard is going to cause me issues. Am I reading this correctly?

[Mike680]

Originally Posted by Locktite

So I just bought 2 Ultraguards for 2 of my machines which are running HW 160A ESC's..I haven't gone through this whole thread yet, but it seems like the ultra guard is going to cause me issues. Am I reading this correctly?

No, it shouldn't cause issues. I did testing with an UG, iKON and HW 120 and nothing bad happened. I posted extensively about it in the HW forum.

[Locktite]

Ok sounds good.. So just plug the ultra guard into my aux slot on my Spartan vx1e and n and I am good to go. You can go crazy with this hobby with all these issues/fixes with certain products..

[Mike680]

Originally Posted by Locktite

Ok sounds good.. So just plug the ultra guard into my aux slot on my Spartan vx1e and n and I am good to go. You can go crazy with this hobby with all these issues/fixes with certain products..

That's what I did with my iKON. My findings showed that, yes, the UG will backpower the HW through the BEC and run the motor when the main flight pack is unplugged simulating a complete power loss. But, it will run the motor at an extremely low RPM. Maybe a few hundred RPM at the most and that was on the bench. With blades installed, it would be even less. Switching flight modes to higher and lower governed headspeeds did not affect the motor speed. I let it run for a solid two minutes being powered just from the UG and nothing got hot or even warm. In reality, that's unrealistic because a main flight pack failure that forced the UG to take over would manifest itself as an immediate motor failure with the huge power loss. You'd be hitting TH in a second or two anyway and the motor definitely stops when TH is on.

[Locktite]

So if I understand correctly, when I unplug my main battery the ultra guard takes over(thinking power failure) and backfeeds voltage through the internal BEC in the esc and gives some power to the motor which eventually drains all the power from the ultra guard battery..Now If I always unplug my main battery packs with throttle hold on I shouldn't have any spoolup from the motor..

[Mike680]

Originally Posted by Locktite

So if I understand correctly, when I unplug my main battery the ultra guard takes over(thinking power failure) and backfeeds voltage through the internal BEC in the esc and gives some power to the motor which eventually drains all the power from the ultra guard battery..Now If I always unplug my main battery packs with throttle hold on I shouldn't have any spoolup from the motor..

Correct. But, when you say "eventually drains the UG", that's a non-starter. That won't happen in reality. Again, I let it run for two minutes testing while checking for heat production due to excessive current draw. I found none. That two minute test run is unrealistic, anyway. Nobody would do that in actuality unless they did it on purpose on the bench like I did. In flight, you'd hit TH in an instant in flight when a main flight pack power failure occurred. And, yes, with TH on the motor will never run as long as TH is set up correctly. After a flight and before I unplug the flight pack, I press the UG button for a 2-3 count and that shuts it off. You can then unplug the flight pack and everything will stay powered off.

[Locktite]

Good to know.. Thank you

[Mike680]

Originally Posted by Locktite

Good to know.. Thank you

No problem. I really wanted to get to the bottom of the issue so that's why I put my equipment at risk. Thankfully, everything turned out A-OK.

[Locktite]

Well I read most of the thread and there are some good points.. I don't understand why this issue wasn't thought before designing the ultra guard if it was an issue..I am a little concerned and feel this unit can cause more harm then good... Or am o just overthinking this..seems like you can have some big issues if you don't turn power off on the ultra guard before the main flight battery

[Freeskiken]

Originally Posted by NHENRY

Does anyone know if a 2s LiFe pack can be used to power the Ultra Gaurd? I would prefer to use a LiFe pack due to it being safer than LiPo packs!

Did anyone find a sutable LiFe battery for the OUG ?

https://www.amainhobbies.com/protek-...k-5183/p177906

Not sure if this would work ? I could solder the OUG connector to the wires. But the LiFe only has two wires will this work ?

[helirifick]

As discussed earlier, couldn't you just install that Schottky diode on the + side inline (not reverse) between the ultra guard and where it plugs into the receiver? Or would the 0.57V (0.63V ?) forward voltage drop confuse the ultra guard?

The other option is going with the BECguard which gets expensive (you may need 2 of them for a high current, high voltage heli setup).