I read through some of Trappy's recent thread about rules for a setup, and it got me thinking about re-planning mine. Unfortunately, it looks like his thread has turned into a battleground, so I'm reposting my question here.

I imagine this has been answered, but I didn't have much luck searching for it because I got a flood of irrelevant search results. So, here goes:

I am building a jet with a 6s flight battery and a 900/500 FPV setup. I originally planned to use a dedicated FPV battery, but Trappy's post led me to reconsider this (assuming I understood what he was saying about batteries). Here are a few questions I have:

1) Is there any reason not to use a dedicated FPV battery? Is it better to step-down the 22.2v flight battery? My concern here is that, because it's not a glider, the flight battery is depleted quickly and may cause Tx strength problems.

2) If I use a dedicated 3s battery, should I still use a voltage regulator? If so, can someone suggest one? It looks like the input voltage for most 12v step-up regulators is in the 4v-6v range. Is there a better way to provide steady 12v power to the Tx and camera?

3) I plan to rewire all the servos with twisted wire. Is there any other shielding that should be done? Should I still use Ferrite cores on all of them? If so, where should I place the cores (close to the servo, close to the Rx, or in the middle)?

Thanks,

TL

Would this voltage regulator be a good choice for the Tx and camera:

http://www.dpcav.com/xcart/product.p...5&cat=0&page=1



Would this help to maintain steady signal strength throughout the flight?

-TL

Originally Posted by wtl0715

I read through some of Trappy's recent thread about rules for a setup, and it got me thinking about re-planning mine. Unfortunately, it looks like his thread has turned into a battleground, so I'm reposting my question here.

I imagine this has been answered, but I didn't have much luck searching for it because I got a flood of irrelevant search results. So, here goes:

I am building a jet with a 6s flight battery and a 900/500 FPV setup. I originally planned to use a dedicated FPV battery, but Trappy's post led me to reconsider this (assuming I understood what he was saying about batteries). Here are a few questions I have:

1) Is there any reason not to use a dedicated FPV battery? Is it better to step-down the 22.2v flight battery? My concern here is that, because it's not a glider, the flight battery is depleted quickly and may cause Tx strength problems.

2) If I use a dedicated 3s battery, should I still use a voltage regulator? If so, can someone suggest one? It looks like the input voltage for most 12v step-up regulators is in the 4v-6v range. Is there a better way to provide steady 12v power to the Tx and camera?

3) I plan to rewire all the servos with twisted wire. Is there any other shielding that should be done? Should I still use Ferrite cores on all of them? If so, where should I place the cores (close to the servo, close to the Rx, or in the middle)?

Thanks,

TL

Since nobody seem to answer I try...

1)
Fewer components have the advantage of less risk of one failing. I think though that the biggest risk of a dedicated battery of the FPV path is that you have one battery more to handle which discharges differently than the flight battery leading to situations where you may decide to use it for another flight wehn you should not etc. So I share my opinion with what Trappy says and go for a step down regulator. Note though that such regulators often have a ripple which is too high. The one you presented in your other post seems ok except for the ripple and the fact that it's out of stock.

2)
I power my TX and camera as slaves of the OSD I'm using which takes the role of stepping up/down the input voltage given by the 3S battery. If your OSD can't do this or if you don't want to use one then you must go for a converter like the one you posted. Just also add a good filter behind it like the one available from the same site.

3)
I would not go the extra mile with the ferrite rings on all servo leads as long as you do not experience trouble when testing your system.

HTH

Markus

Originally Posted by markus123456

Note though that such regulators often have a ripple which is too high. The one you presented in your other post seems ok except for the ripple and the fact that it's out of stock.

You're right, it is out of stock. I looked around and found a few more, like this one:



It can handle (survive) up to 42v in and has adjustable V-OUT. In order to control the ripple, which I assume is the same as the initial voltage spike that the regulator may experience when first plugged in, I think that I could prevent it with a capacitor (I'm not an expert, so I hope someone will correct me if I'm wrong about this).

Any other opinions here? I'd like to hear both sides if others prefer a dedicated FPV battery.

-TL

Originally Posted by wtl0715

You're right, it is out of stock. I looked around and found a few more, like this one:



It can handle (survive) up to 42v in and has adjustable V-OUT. In order to control the ripple, which I assume is the same as the initial voltage spike that the regulator may experience when first plugged in, I think that I could prevent it with a capacitor (I'm not an expert, so I hope someone will correct me if I'm wrong about this).

Any other opinions here? I'd like to hear both sides if others prefer a dedicated FPV battery.

-TL

For your application with 6S a step down converter is surely sufficient. Make sure though that it can handle the current of all components you add to it on it's output.

Getting rid of the ripple can be difficult. A capacitor alone is most likely not sufficient. You would need at least an LC filter (a coil and capacitor) but even then it's not always that easy. If you search this forum you will find sufficient information on filters though.

How bad the ripple is depens on the regulator and also of course of what you connect to the output meaning that some devices (cameras, video tx and so on) filter good enough for their own needs. So you could try and add a filter as you go.

Markus

Ok guys, here's what I'm thinking:

6s battery - Polou 12V step down regulator - LC filter (already have the one from dpcav) - camer/tx/etc

Anyone foresee any issues with that setup?

-TL

Another thought....would this be a good setup for me to consider using an OSD? If I use an OSD, I would go with the Eagle Tree Systems setup. It appears to be pretty user-friendly and would allow me to set up antenna tracking later if I so choose. I've never used one before in three FPV setups, but maybe this is a good time to use one. Any thoughts?

-TL