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Old Jun 22, 2011, 12:20 AM
Specializing in RC since 1972
Temple, GA, USA
Joined Jun 2009
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Originally Posted by Blueshy View Post
NONONONONONONONONO!!!

Do not cut the black wire anywhere before the plastic split in the cord. Go to the end of the cord and cut it there. Find the video out cable, cut the video connector off (the yellow one), cut back the ground wire inside, and only solder the inner yellow wire to your VTx Video in (the yellow one on the VTx). Omit the ground to ground connection on that wire.

Also you should unsheath your VTx out of its heavy heatsink. If you plan to run it without air cooling install a heatsink to it.

Blues
Please don't do that. Believe me, I am not trying to cause a scene here, but that only clouds the issue and will not help unless he has a very particular kind of mis-wiring problem that should be corrected the right way.
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Old Jun 22, 2011, 12:26 AM
Specializing in RC since 1972
Temple, GA, USA
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Originally Posted by efx View Post
Okay. I don't have it yet so we'll see. Also, I can use the regular 11.1v 2200mAh batteries with this correct? I don't have any other batteries at the moment aside for a sealed lead acid 12v battery. So due to this I haven't made any connectors yet since I'm not sure what I'll be using for this system.
There is only one time I can think of in FPV/RC that you need to worry about ground loops at all and that is when you have an OSD with a current sensor AND connections to your RC system, and even then the problem is much less common than some posters would claim.

Edit: I thought of another time. When you get FPV power from the flight battery and the FPV has an OSD that connects to the RC receiver (like a servo connection from the receiver).

Please do not cut any grounds anywhere.
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Old Jun 22, 2011, 12:35 AM
Specializing in RC since 1972
Temple, GA, USA
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Originally Posted by efx View Post
Sounds great, do you have any links to those voltage regulators? Sorry, I've never bought any. Not sure if HK would have something I can use. The camera, receiver and transmitter are 12v.
Voltage regulators are generally used with a higher voltage battery like a 4 cell; dropping it down to 12 volts. Some people drop down to 13 volts or even higher to run their FPV transmitter at a higher voltage for the (slight) range increase.

It takes a special kind of regulator to take 11 to 12 volts input and put out a constant 12 volts.

I have not yet had to use a 12 volt regulator in my systems. I have used one battery for motor and FPV and I have used two separate batteries.
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Old Jun 22, 2011, 12:49 AM
OSUFPV - KF7VFT
Corvallis, OR
Joined Apr 2010
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Originally Posted by theothercliff View Post
Please don't do that. Believe me, I am not trying to cause a scene here, but that only clouds the issue and will not help unless he has a very particular kind of mis-wiring problem that should be corrected the right way.
I know it works. Why? Because I did the same thing with the same setup and now it does. Unless you have had this camera you really don't know. But I'll let him fix his own problems however he chooses to. I'm willing to bet if he does what I said it will fix it. The problem solving method you gave is pretty much what I did to find this solution in the first place.
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Old Jun 22, 2011, 12:49 AM
Specializing in RC since 1972
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Originally Posted by JLager View Post
I'm planning to use a similar device once I get my FPV setup ready. Some people say it works fine and some people say there's a significant delay in the video (as it has to convert the analog video to digital to display on your computer) making it difficult to fly. I'd say give it a try first and see what happens. Perhaps do a bunch of delay tests on the ground first
There is a delay. On a properly configured system it will be about a quarter of a second IIRC. In really bad circumstances, that can be enough of a difference.

This is generally only a problem:
- with unstable airplanes
- during unstable maneuvers (take off from ground can be more difficult if you have to jump on the rudder instantly to keep it straight)

The only capture software that I have used is the EasyCap software. It is more about the codec you use any way. I use mpeg2 at 5000 to 6000 data rate for good quality, smooth, low latency because of its low CPU demand.

No, that is not true. I have used vidcap (vidcap32?), (free, simple, capture/display only) but it doesn't come with any codecs so you are stuck with what you have on the system (not the best for what we do).

Delay tests on the ground YES. Good idea. Make sure it is smooth too. Make sure it is actually capturing in 640x480 or 720x480 (or 576 instead of 480 for non-USA).

If the delay is too high or the resolution is too low (or otherwise bad) you have to play with codecs (type, data rate, and capture size).
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Old Jun 22, 2011, 01:13 AM
Specializing in RC since 1972
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Originally Posted by rcflyboynj View Post
I am not sure if this question has been asked already, but I would like to be able to use my lap top as a screen to fly from. Right now I have a pinnacle dazle, (most basic one) am running Windows 7 64 Bit, AMD Dual Core 2.1Ghz processor, 3 gigs ram, 15 in display. I basically need to know what program one would use, and/or is it possible to use this setup?

Thanks,

Nathan
One day I forgot my EasyCap but had my laptop. I called a friend that was coming out to fly and he brought his Dazzle. I got it working, although I only got 320x240 out of it. I don't know if that was all that model of Dazzle would do or whether I needed more software to configure it for 640x480.

Your laptop has plenty of power for what you want to do. Software and testing will be the keys to success. What are you going to use for capture software? vidcap32 works (on XP at least), but you will be limited to the codecs that come with Win7.

Get all your software figured out, configured, and tested at home, because it can take days...

For about $20 (?) you can get a new version EasyCap that works with 64bit (64 bit is important) Win7. It comes with usable software, at least the old XP version of EasyCap did. I triple boot my new laptop just so I can run XP (and Linux and Win7) with my old EasyCap's.

You will need a cardboard dark box so you can use it in daylight. I started with a closed box. Cut a slit in one end to slip the screen in against the back wall. Cut a face shaped hole in the front wall. When my face is in it, no light can get in. You don't have to go quite that radical, but I would start there, and if you don't like the face hole, cut out that whole square side.
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Old Jun 22, 2011, 01:31 AM
efx
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Interesing, thanks for all the info to both of you. This whole conversation just got me thinking about this. I haven't done anything on my end, but it did peek my curiosity.

So are you using this system as is without cutting anything cliff? I mean none of the smoke coming out of your system? He did say he got his camera off ebay and not the security2000 so I'm wondering if that may be playing a part, meaning the camera itself since that's where it looked like the wires started to melt. I wouldn't have a problem cutting the negative off, but I just wonder.

I did an interesting test though. I wrapped electrical tape around the negative side of the adapter where the video plugs wire plugs into and I then put the camera in there and it looks like that may work too without cutting off the wire if anyone is really interested. Cheap quick way to test this out before cutting anything. Wrapped the yellow outer plug in electrical tape, try the video and see if that works too. I haven't tried it, I was just doing this right now to test for continuity.


Quote:
Originally Posted by theothercliff View Post
Voltage regulators are generally used with a higher voltage battery like a 4 cell; dropping it down to 12 volts. Some people drop down to 13 volts or even higher to run their FPV transmitter at a higher voltage for the (slight) range increase.

It takes a special kind of regulator to take 11 to 12 volts input and put out a constant 12 volts.

I have not yet had to use a 12 volt regulator in my systems. I have used one battery for motor and FPV and I have used two separate batteries.
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Old Jun 22, 2011, 02:08 AM
OSUFPV - KF7VFT
Corvallis, OR
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Originally Posted by efx View Post
I did an interesting test though. I wrapped electrical tape around the video negative sides and I then put the camera in there and it looks like that may work too without cutting off the wire if anyone is really interested. Cheap quick way to test this out before cutting anything. Wrapped the yellow outer plug in electrical tape, try the video and see if that works too. I haven't tried it, I was just doing this right now to test for continuity.
Right, that's the redundant video ground connection that causes the short I was telling you to cut. I cut off all of those plugs on every single connection on my plane and either solder them directly and apply some liquid electrical tape, or combine and replace the plug with a servo plug connection instead. Those plugs are just bulky, unreliable, and annoying so I don't mux with them at all.

Blues
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Old Jun 22, 2011, 02:38 AM
If it's to be, it's up to me.
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Sydney, Australia
Joined Jan 2007
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Here's a noob question for you:

I'm planning on using a mouse cable to provide shielded wires for my camera - OSD connection and camera power. I'm making a new camera harness anyway for my new cam, so is this good practice, or more trouble than it's worth? Question is, what do I earth the shielded portion to, or do I run the -ve wire to the shield?

Just a note of thanks for those that spend their time replying to the questions on here. I thought I knew all there was to know about RC aircraft until I found this thread. I'd been ignoring it for ages thinking Ahh, that's for Noobs! Shows that you're never too old to learn!

sub.
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Old Jun 22, 2011, 02:40 AM
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United States, WA, Enumclaw
Joined Nov 2001
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Thanks for going into such detail and working overtime on my Cliff System guys!

A 4 hour drive for work this afternoon was killing me... I knew good stuff was happening here on the threads and I wasn't going to be able to participate until late

Good news is that the supplier (edogpro) has already sent me a note stating that a new cable/plug has been shipped to replace my singed component. IN the meantime, I will be insulating the exposed copper on that plug and giving it another test.

More tomorrow.

Oz
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Old Jun 22, 2011, 03:09 AM
Specializing in RC since 1972
Temple, GA, USA
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Originally Posted by efx View Post
...
So are you using this system as is without cutting anything cliff? I mean none of the smoke coming out of your system? He did say he got his camera off ebay and not the security2000 so I'm wondering if that may be playing a part, meaning the camera itself since that's where it looked like the wires started to melt. I wouldn't have a problem cutting the negative off, but I just wonder.
That is right. I cut the transmitter "power in" plug off and replaced it with something I can plug into my 3 cell lipos. I just plug it all together as described elsewhere. FYI: I actually use a JST-XH (lipo balance connector) here so that I can power my FPV from my flight battery balance connector if I want to.

Quote:
Originally Posted by efx View Post
I did an interesting test though. I wrapped electrical tape around the video negative sides and I then put the camera in there and it looks like that may work too without cutting off the wire if anyone is really interested. Cheap quick way to test this out before cutting anything. Wrapped the yellow outer plug in electrical tape, try the video and see if that works too. I haven't tried it, I was just doing this right now to test for continuity.
Imagine your camera with the video ground cut. Imagine you have a battery connected to the camera. The only cable you have coming out of the camera / battery package is the video cable, and you plug the video cable into a TV to see if the camera works. It doesn't. Because the video ground is cut.

Conceptually, ground is a single wire that runs through the whole system and all voltages are relative to the ground. It doesn't matter whether you have 2 wires or 3 connecting points A and B and doing surgery to reduce the number of wires that connect A and B is unneeded here and can cause tests in the future to fail. For full disclosure, there is a thing called a ground loop, but that just doesn't matter here at AV frequencies and small amounts of power. You have to have large enough currents flowing for there to be a detectable voltage difference between one end of a wire and the other or there has to be tuned resonance on the wire.

The plug that got hot was the one on the camera right? Then that is where the short was. If the short was closer to the battery, then there would be no power or heat at that plug. The one bad thing is that all this could be caused by an internal short in the camera.

Find what could have shorted and make sure it can't do it again. Don't let the two boards touch. Don't set the boards down on anything metal. Don't let messed up wires or pins at the plug touch each other or the boards.

Do your initial testing with a wall wart and not a battery. Make your tests very short (5 seconds) with camera directly connected to a working display on a display input that you have tested before hand with a different video source. Test your wall wart with a small 12 volt bulb afterwards to make sure it still works.
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Old Jun 22, 2011, 03:20 AM
Specializing in RC since 1972
Temple, GA, USA
Joined Jun 2009
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Quote:
Originally Posted by subsonic View Post
Here's a noob question for you:

I'm planning on using a mouse cable to provide shielded wires for my camera - OSD connection and camera power. I'm making a new camera harness anyway for my new cam, so is this good practice, or more trouble than it's worth? Question is, what do I earth the shielded portion to, or do I run the -ve wire to the shield?

Just a note of thanks for those that spend their time replying to the questions on here. I thought I knew all there was to know about RC aircraft until I found this thread. I'd been ignoring it for ages thinking Ahh, that's for Noobs! Shows that you're never too old to learn!

sub.
Once you get past the "just plug it in" stage and want to get rid of that extra weight, some re-wiring is in order. I personally am not that weight constrained so I leave my cables alone. Testing and re-configuration is easier for me that way.

Mouse cable sounds great. I have bought some small (Panasonic CX-161) cameras and plan to do something similar if HK ever ships my airplanes.

If you are re-wiring anyway the mouse cable sounds great, but do you need to re-wire or even just want to re-wire?

I would connect the shield to the circuit ground (as long as there is a wire associated with the shield to make it easy), but you could use one of the internal wires for ground too.
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Old Jun 22, 2011, 04:02 AM
OSUFPV - KF7VFT
Corvallis, OR
Joined Apr 2010
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Quote:
Originally Posted by theothercliff View Post
Imagine your camera with the video ground cut. Imagine you have a battery connected to the camera. The only cable you have coming out of the camera / battery package is the video cable, and you plug the video cable into a TV to see if the camera works. It doesn't. Because the video ground is cut.
Right, but in the relevant situation the VTx already shares a common ground with the battery and camera so there is no need. If you were going to hook it up to a TV you would obviously need a ground so that the signal would have a relative reference voltage. The problem here is that for some reason when you use that ground from the video out cable and the power together a short occurs.
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Old Jun 22, 2011, 09:33 AM
Specializing in RC since 1972
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Originally Posted by Blueshy View Post
Right, but in the relevant situation the VTx already shares a common ground with the battery and camera so there is no need. If you were going to hook it up to a TV you would obviously need a ground so that the signal would have a relative reference voltage. The problem here is that for some reason when you use that ground from the video out cable and the power together a short occurs.
I'm sorry but this is wrong.

If you have a voltage regulator wired in the circuit, then I suspect that it is wired in a way that requires you to cut the video ground, and that is the cause of this discussion.

A negative 5 volt regulator for a 5 volt camera would require you to cut the ground in the video cable as you have done. Negative regulator circuits are uncommon and not recommended because of this. A positive 5 volt regulator would not have this problem.

From the description of the cut in the wiring and the fact that it works, I am guessing that you have the positive power lead for your (5 volt) camera connected to +12v (the battery positive terminal) and the negative power lead for your camera connected to the voltage regulator output.

Is this the case?

It is either that or the video cable shield is connected to plus volts at the camera side or connected to plus volts at the vtx side when it should be connected to ground on both sides.
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Old Jun 22, 2011, 09:38 AM
efx
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I also agree with what cliff said about the wiring. Now I'll have to wait for my camera case so I don't take any chance on shorting it while testing.
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Last edited by efx; Jun 22, 2011 at 09:43 AM.
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