micro video camera voltage ratings

[vector_vortex]

Hi,
I bought what was marketed on eBay as a wireless spy camera, with intent to use it as a UAV camera. It has an integrated 2.4Ghz transmitter built into the unit, the only plug is for power. However, it says it requires an 8V power supply. I don't want to have to build a custom DC-DC converter to operate the camera in the plane. I would like to run it off the 11.1V lipo directly, I have one lipo for comms and another for motor so the power rails should be relatively clean.

Since it's pretty much all analog circuitry I figure the 8V supply is to stay under 200mW power output laws.

Has anyone had experience running a cheap eBay wireless "spy" camera at a higher voltage than rated?

Thanks

Joel

[Blue Sky]

I usually run mine on a 2 cell lipo.
These things may draw close to 200mw but they only poop out 10 mw or so.
3 cells won't give any better performance since the camras usualy have a 5 volt regulator. All you'll do is burn more juice. The voltage needs to be close to 8
volts for the regulator to work properly.
The regulator is often built into the power plug to avoid interferance
problems. Don't remove it!

-Dave

[questtek]

I agree since I have had some experience with them. If you are up to it you can take the back off the camera and see the three wires, four if you have audio. Color coding is conventional and the circuit board is marked.

There is a 5 vdc Regulator built into the power plug, a 7805. This is a cheap, inefficient regulator so putting in around 12 volts means you burn up 7 in heat to get the 5 required. You might consider getting a switching regulator and just wire it in..this way your 3 cell LiPo voltage to camera 5 VDC is efficient and not adding to the Green House Effect.

BUT, AND HERE IS S BIG BUT. Often these cameras are highly sensitive to noise and powering it from your main battery may generate lines and hits on the video from the motor...even if it is brushless. A simple test will confirm the sensitivity.

Best, Joe

[vector_vortex]

Thanks for the replies.
I opened the camera up again, I had taken it apart to remove the IR filter previously but didn't take as much notice as I am now. I found three wires coming from the power plug, One red at 5V DC, one Black for ground and one white wire. The standard yellow and black wires connect the CMOS sensor to the RF subsection.

The odd thing is the white wire seems to be at 18V AC at a frequency of 17khz though my freq meter could be aliasing. Can anyone shed more light on how or why or what the white wire is for.

How did you go opening up the power plug, it seems pretty well sealed/encased??

The motor is run off a separate battery to the communications/TV system so I will try to reduce noise as much as possible by zoning etc.

Thanks for your responses.

Joel

[vector_vortex]

By the way,
have any of you built your own 1.2/2.4Ghz amplifiers to boost the output power levels, the little transmitter board in mine doesn't look like the most high power design! Actually it's quite strange, It's a two layer SMT board with pads on both sides but only components on one side, weird!

If you have build signal amplifiers, where did you find the schematics and what amplifying device/s did you use???

Thanks

Joel

[vector_vortex]

I seem to be answering my own questions, that white wire is a passthrough straight from the DC in, the meter must have been measuring the field in the air surrounding the antenna or something. I have found the regulation circuit board and will use a DC-DC converter from another source to power this. I am seriously considering building a more efficient 1.2 GHz power amplifier/modulator. any ideas?

thanks

Joel

[questtek]

I guess you dug the 7805 regulator out of the molded power plug.
If you want to build up your own amps look at a company called MiniCircuits (Google it)
They will have what you want interms of new lightweight chip amplifiers.
Best, Joe

PS, I found it is much easier to buy a light weight amp module and tie in a better camera. The camera in the set up you are using is very poor in terms of quality but great in terms of low price.