Scorpion Backup Guard

[jamesg53]

Anyone using one of these with a kosmik bec set at 7.4v just orderd a couple but want to make sure it will be ok to use with it first?

[crf69]

it will be ok.....all it does is supply power if the bec drops below 5.0volts.



Sent from my phone using Tapatalk2...otherwise i would of sent it from my home PC.

[Freeskiken]

Ok so I made the charging cord for it like Mr Mel showed in his video. I clipped the middle pin on the servo extension. So now I have two out side pins.

I have a servo plug on the other end. I can't charge through it because the charging cord I have with a servo plug charges though the middle pin being positive and one of the outside pins being negative.

So I would have to cut this off and solder on say a JST plug ? The negative on the JST to the negative on the new charge cable and the positive to the outside wire (white wire on Futaba servo cord) on the charge cord. This way I would charge through the two outside pins. So this is how you charge this backup pack through the two outside wires ? One negative and one positive ? The red wire in the middle of the balance plug is for what ?

help

[Freeskiken]

It turns out it is the outside two wires that would need to be connected to the charger. The middle wire is for balancing.

[colcha]

Originally Posted by jamesg53

Anyone using one of these with a kosmik bec set at 7.4v just orderd a couple but want to make sure it will be ok to use with it first?

Originally Posted by crf69

it will be ok.....all it does is supply power if the bec drops below 5.0volts.

There seems to be conflicting advice on this point. See:

https://www.helifreak.com/showthread...99#post4426899

Anyone else want to chime in?

[satgod]

scorpion did a nice job on this and for the price you would be hard pressed to copy it

it is a power BACKUP like the UPS supply for your computer
if or when the power drops below 5v it takes over and starts supplying power at 5v so you can land without problem. It could help with brownouts as well but a large capacitor can do that.

you could build this same circuit with a cc 10amp bec, 1 diode (rated at 20amps), a small 2s battery and a servo Y-harness
Like I said it would be hard to beat the price and then the packaging probably dont look as good either.

if you want to protect from brownouts a large capacitor (1500uf at 50+v, 63v is good) is a better choice
if you run your bec off your flight pack for your motor this is a good backup

[zeeflyboy]

Wonder why they didn't use Life packs...

They are much more suited to being left fully charged for long periods. Perhaps it's possible to dismantle and replace the cells with Life (assuming it will run from 6.6v)

[satgod]

why would you build a backup from a Life pack when you could just fly the LiFE pack

even with a Life pack you could make a backup but with the LiFE outputing 6.6v your bec would have to be at 7+ v or the LiFE would always be draining unless you used a voltage reg. and pulled it down to about 5v
which again just run the lifepack or your back to the backup being a better choice

[zeeflyboy]

Because things aren't always as simple as you think

The project I'm doing at the moment and looking at this for is far from normal.

But regardless, you can say the same about the thing as it is anyway - why not just use a life pack. The function remains the same whether the scorpion would be powered from a lipo or a life, it's just that life would be a better choice (IMO) for something that it'd be good to leave fully charged for long periods.

I use separate packs on my 600, and sometimes I'd rather just use a BEC and do away with charging extra packs. That's where this would come in as a safety net.

[satgod]

understand but to use a life back as a backup the basic and most simple circuit to dis-connect the life back from the system till power drops off is a diode setup to be in reverse polarity as long as the power coming from the main source stays high enough to keep it in this state. then when the power drops the diode would be biased via the LiFE pack and power would flow to the electronics. if the system is a 5v system you would have to include a voltage regulator to take the voltage down to 5v and then bias it for voltage switching
This is what I use to do.

[desertstalker]

Originally Posted by satgod

if the system is a 5v system you would have to include a voltage regulator to take the voltage down to 5v and then bias it for voltage switching
This is what I use to do.

Most servos will take a Life with no issues, especially if there is a diode dropping the voltage a bit. Any 6V specced servo is designed for use with 5S NiCd RX packs and will happily handle 2S LiFe (the same ~7.2V when fully charged).

[satgod]

I understand that but what i'm saying is your backup source can not exceed your main source in power or it will override the low voltage power switching and become the primary power unit it goes below the true primary source
if you run a life pack and use a life pack as the back then a simple diode reverse biased would be all you need for the back up
but if you run a 6v bec and you the life pack as the backup even with the diode voltage drop your life pack could still be biasing the diode and becoming the primary source

[Ronnie Mund]

I'm finalizing my Goblin 630 build plans, and just learned of this device.

I'm planning on running a CC BEC Pro directly off my 12S flight pack, to power my AR7200BX with Torq BL servos. Would you guys recommend I pick up the Scorpion Backup Guard as a backup?

Thanks

[NRPY]

Originally Posted by colcha

There seems to be conflicting advice on this point. See:

https://www.helifreak.com/showthread...99#post4426899

Anyone else want to chime in?

Not conflicting advice; rather, it is a different issue. Jive BEC can shut down for up to 250ms due to high servo back EMF. This 250ms window is unfortunately enough to cause some FBL controllers to reset (in flight ). I don't know how fast the Backup Guard can respond to changes in voltage. If it can respond within this 250ms window, it should be able to deal with the Jive BEC's "brownout".

However, the Backup Guard seems to be designed to handle BEC failures, rather than quick brownouts.

[hemp]

It really seems like a "buffer pack" is a better solution all around than a backup guard like this. First because buffer packs keep themselves charged and second because they cover both receiver brownouts and (assuming the pack is large enough) ESC failures.

The biggest downside I see with a buffer pack is weight - 5 AAA's would be a beefy addition to a 450-500, whereas a small lipo may be tolerable.

[ArguZ]

Linus Greencaps

[gixster]

i ended up making a charge cable using a 12" 2s balance lead extension cable and a jst charge cable. i cut the jst plug off and soldered it to the outside wires of the extension cable
works great

[crf69]

well not sure what the issue is with one of my backup gaurds but its blinking when i come down after a flight.

cells are still 4.18 and fully charged.

i have no idea why its doing this.

Sent from my phone using Tapatalk2...otherwise i would of sent it from my home PC.

[Libtekguy]

Interesting device. I'm running a straight 2S LiFe on my 600 Pro, and I've always been a little concerned about something coming unplugged or just straight failure. I have a DX8 running telemetry, it would be easy for me to set up an alert on my TX that I'm running at 5v rather than 2S LiFe.

Has anyone tested this device to see if it "takes over" supplying power fast enough for the FBL controller to stay on and not reset? I would like someone to completely disconnect their BEC or receiver pack and see if this takes over fast enough for their FBL (specifically an AR7200BX if possible) to keep functioning normally.

[gixster]

Originally Posted by Libtekguy

Interesting device. I'm running a straight 2S LiFe on my 600 Pro, and I've always been a little concerned about something coming unplugged or just straight failure. I have a DX8 running telemetry, it would be easy for me to set up an alert on my TX that I'm running at 5v rather than 2S LiFe.

Has anyone tested this device to see if it "takes over" supplying power fast enough for the FBL controller to stay on and not reset? I would like someone to completely disconnect their BEC or receiver pack and see if this takes over fast enough for their FBL (specifically an AR7200BX if possible) to keep functioning normally.

Iam in the middle of putting one on my trex 550 dfc.
I am currently running the beastx AR7200BX.
the backup guard works as advertised, the switch is instantaneous and the beastx does NOT reset.