OptiGuard Failed

[Bungy15]

I still favour the cradle for holding the Lipo as I believe in panic mode when trying to remove a smoldering/Flaming Lipo it would be easier to quickly remove the R clip and pull on the wires rather than trying to undo the Velcro etc................ still anything that makes the LiPo quickly removable has got to have its plus points.

[cjcj1949]

cjcj1949,

The Ultraguard can only deliver 7A or 10A in bursts which is about half of what a good quality HV BEC can deliver. So if the BEC has already shut down due to overload then the ultraguard wont have a chance of meeting demand.

A 2s Lipo 2200mAh can deliver 60 Amps or more which is several times more than you would ever need, so i'd argue that this would be a more reliable solution, plus simpler and cheaper.

I wasn't arguing for the best solution. Solutions get very complicated in this area. If for instance you use a very current supply for the servos you will initially keep the system running, but you will only be able to do that for a short while before the servo fails. Using a bridge arrangement of fets is very good until one doesn't turn off properly and then you have a short across the supply.

If we run our helis well below their max spec then we can have reliability, but if we try to get the max out of them then we move towards a F1 or jet engine situation where we need to monitor many things to catch failure situations before they get fatal.

As an example we can easily monitor temperature of servos and escs and send a warning back to the pilot allowing a safe landing to be made.

It all comes down to money in the end though. Even in F1 they don't always catch the failures before the wheels come off.

[Planehazza]

I wasn't arguing for the best solution. Solutions get very complicated in this area. If for instance you use a very current supply for the servos you will initially keep the system running, but you will only be able to do that for a short while before the servo fails. Using a bridge arrangement of fets is very good until one doesn't turn off properly and then you have a short across the supply.

If we run our helis well below their max spec then we can have reliability, but if we try to get the max out of them then we move towards a F1 or jet engine situation where we need to monitor many things to catch failure situations before they get fatal.

As an example we can easily monitor temperature of servos and escs and send a warning back to the pilot allowing a safe landing to be made.

It all comes down to money in the end though. Even in F1 they don't always catch the failures before the wheels come off.

Yup, and yes, the UG430 has a constant current rating of 7A, but the idea is not to purposely fly on this. As soon as you see that LED flash, you land. Its sole purpose is do give you enough juice to land. jsut because 430mAh is enough to have 2 whole flights, doesn't mean you should

I guess what I mean is this: 7A may not be enough to deliver enough power for constant ticktocking 3D flight, but it's not meant to. Land as soon as you see that LED and you're fine.

[Grumpy]

I guess what I mean is this: 7A may not be enough to deliver enough power for constant ticktocking 3D flight, but it's not meant to. Land as soon as you see that LED and you're fine.

I'm sure everyone does understand that. The point of my last post was that 'if' the main BEC had failed and shut down due to overload (which was claimed to be the purpose of the UG in a previous post) then the UG wouldn't be able to cope either and would itself fail, because it's rating is actually less than most decent quality BEC's.

It would of course protect against other types of BEC failure but in a straightforward overload condition where the main BEC shut-down it wouldn't have much hope. To be honest though overloading of a 20A HV BEC, or more so a 2s unregulated LiPo, should never occur anyway.

[bigpops]

It's purpose it to protect your heli if the BEC fails due to overload specifically, just if the BEC fails with no output. That can be any number of reasons. Poor soldering of the main flight battery connector being the one I see the most. No BEC can work with no input voltage, unfortunately.

If the BEC fails and lets through the whole pack voltage, your electronics are generally toast, including the ultraguard.. But there's protection for that too.

[Granpappy]

I'm sure everyone does understand that. The point of my last post was that 'if' the main BEC had failed and shut down due to overload (which was claimed to be the purpose of the UG in a previous post) then the UG wouldn't be able to cope either and would itself fail, because it's rating is actually less than most decent quality BEC's.

It would of course protect against other types of BEC failure but in a straightforward overload condition where the main BEC shut-down it wouldn't have much hope. To be honest though overloading of a 20A HV BEC, or more so a 2s unregulated LiPo, should never occur anyway.

As I understand it, if the main BEC were to overload and cut power, the UG would detect the voltage drop and switch in to an overloaded system. How long would it take for the UG to fail from overload? Would there be enough time for the pilot to reduce the flight envelope to one that can be supported by the UG?

Also if the main BEC were to fail due to overload, would it be immediate? ie. From delivering 100% to 0% in 5 ms? I would have thought that the pilot would get some indication that the system was overloading and take corrective action before main bec failure. Therefore the UG would only need to cope with bec failures which are not overload conditions and therefore switch in seamlessly without failing itself.

[trillian]

But wouldn't it kick in when the voltage starts to drop and essentially 'help out' the BEC before it fails? (depending I suppose on how bad the overload is)

I'm sure everyone does understand that. The point of my last post was that 'if' the main BEC had failed and shut down due to overload (which was claimed to be the purpose of the UG in a previous post) then the UG wouldn't be able to cope either and would itself fail, because it's rating is actually less than most decent quality BEC's.

It would of course protect against other types of BEC failure but in a straightforward overload condition where the main BEC shut-down it wouldn't have much hope. To be honest though overloading of a 20A HV BEC, or more so a 2s unregulated LiPo, should never occur anyway.

[bigpops]

A buffer pack is designed to help your BEC, if your ESC will take a buffer pack. Kontronik do, and YGE low voltage ESCs do as well.

The Ultraguard isn't a buffer pack. It will step in if the BEC voltage drops by more than half a volt, which is quite a lot, so in that sense I suppose it will help if the BEC is struggling that much. It will also flash the LED every time it happens.

I'd argue that if your BEC is struggling and you're overloading it, then something the R2 super capacitor pack will help in such a situation better than an Ultra guard would. That will smooth out drops in voltage instantly, with no need for fancy circuitry to make it work.

You need to choose your BEC wisely. I know the Savox HV brusless that ship(ped) with the Logo 800 XXtreme were incredibly power hungry. Even with and Rx pack, you had to have some capacitance from a Fromeco DC-UP, or run a Scot Gray Reactor from a 3S Lipo. These days, the new Western Robotics BECs will cope with them no problem.

Speaking of which, why does no one sell Western Robotics any more? Seems if you want a decent HV BEC, you have to buy a Gryphon Quasar in the UK.

[Zeeflyboy]

Personally I've yet to see a BEC that out performs the r2 HV2 BEC Alu... plus it even talks to Jlog if that's your thang.

Of course it's not particularly cheap, but in the context of a large heli it's a good investment imo.